3FL11829ACAAWBZZA_02

Introduction to GPRS and E-GPRS QoS Monitoring - B10 - Page 1All Rights Reserved © Alcatel-Lucent 2008

All Rights Reserved © Alcatel-Lucent 2008

EVOLIUMIntroduction to GPRS and E-GPRS QoS Monitoring - B10

STUDENT GUIDE

3FL11829ACAAWBZZA2 Issue 02

All rights reserved © Alcatel-Lucent 2008 Passing on and copying of this document, use and communication of its contents not permitted without written authorization from Alcatel-Lucent



Introduction to GPRS and E-GPRS QoS Monitoring - B10EVOLIUM

2

Empty page

Switch to notes view!

This page is left blank intentionally




3

Terms of Use and Legal Notices

Switch to notes view!1. Safety Warning

Both lethal and dangerous voltages may be present within the products used herein. The user is strongly advised not to

wear conductive jewelry while working on the products. Always observe all safety precautions and do not work on the

equipment alone.

The equipment used during this course may be electrostatic sensitive. Please observe correct anti-static precautions.

2. Trade Marks

Alcatel-Lucent and MainStreet are trademarks of Alcatel-Lucent.

All other trademarks, service marks and logos (“Marks”) are the property of their respective holders, including Alcatel-

Lucent. Users are not permitted to use these Marks without the prior consent of Alcatel-Lucent or such third party owning

the Mark. The absence of a Mark identifier is not a representation that a particular product or service name is not a Mark.

Alcatel-Lucent assumes no responsibility for the accuracy of the information presented herein, which may be subject to

change without notice.

3. Copyright

This document contains information that is proprietary to Alcatel-Lucent and may be used for training purposes only. No

other use or transmission of all or any part of this document is permitted without Alcatel-Lucent’s written permission, and

must include all copyright and other proprietary notices. No other use or transmission of all or any part of its contents may

be used, copied, disclosed or conveyed to any party in any manner whatsoever without prior written permission from

Alcatel-Lucent.

Use or transmission of all or any part of this document in violation of any applicable legislation is hereby expressly

prohibited.

User obtains no rights in the information or in any product, process, technology or trademark which it includes or

describes, and is expressly prohibited from modifying the information or creating derivative works without the express

written consent of Alcatel-Lucent.

All rights reserved © Alcatel-Lucent 2008

4. Disclaimer

In no event will Alcatel-Lucent be liable for any direct, indirect, special, incidental or consequential damages, including

lost profits, lost business or lost data, resulting from the use of or reliance upon the information, whether or not Alcatel-

Lucent has been advised of the possibility of such damages.

Mention of non-Alcatel-Lucent products or services is for information purposes only and constitutes neither an

endorsement, nor a recommendation.

This course is intended to train the student about the overall look, feel, and use of Alcatel-Lucent products. The

information contained herein is representational only. In the interest of file size, simplicity, and compatibility and, in some

cases, due to contractual limitations, certain compromises have been made and therefore some features are not entirely

accurate.

Please refer to technical practices supplied by Alcatel-Lucent for current information concerning Alcatel-Lucent equipment

and its operation, or contact your nearest Alcatel-Lucent representative for more information.

The Alcatel-Lucent products described or used herein are presented for demonstration and training purposes only. Alcatel-

Lucent disclaims any warranties in connection with the products as used and described in the courses or the related

documentation, whether express, implied, or statutory. Alcatel-Lucent specifically disclaims all implied warranties,

including warranties of merchantability, non-infringement and fitness for a particular purpose, or arising from a course of

dealing, usage or trade practice.

Alcatel-Lucent is not responsible for any failures caused by: server errors, misdirected or redirected transmissions, failed

internet connections, interruptions, any computer virus or any other technical defect, whether human or technical in

nature

5. Governing Law

The products, documentation and information contained herein, as well as these Terms of Use and Legal Notices are

governed by the laws of France, excluding its conflict of law rules. If any provision of these Terms of Use and Legal

Notices, or the application thereof to any person or circumstances, is held invalid for any reason, unenforceable including,

but not limited to, the warranty disclaimers and liability limitations, then such provision shall be deemed superseded by a

valid, enforceable provision that matches, as closely as possible, the original provision, and the other provisions of these

Terms of Use and Legal Notices shall remain in full force and effect.




4

Blank Page






5

Course Outline

About This CourseCourse outline

Technical support

Course objectives

1. Topic/Section is Positioned HereXxx

Xxx

Xxx

2. Topic/Section is Positioned Here






1. EGPRS QoS

1. Role of the BSS in GPRS QoS Monitoring

2. Recalls on the Main BSS GPRS Telecom Procedures

3. Description of the Main BSS GPRS QoS Counters and Indicators

4. Detection of the Main BSS GPRS QoS Problems

5. Analysis of the Main BSS GPRS QoS Problems

6. Appendix




6

Course Outline [cont.]






7

Course Objectives


Welcome to Introduction to GPRS and E-GPRS QoS Monitoring - B10

Upon completion of this course, you should be able to:

� Describe the scope of work of BSS GPRS QoS monitoring

� Interpret the BSS GPRS QoS indicators attached to each BSS GPRS procedure or algorithm

having an impact on QoS

� Interpret the BSS GPRS PM counters used in the computation formulae of QoS indicators

� Detect the main BSS QoS problems

� Analyse the main BSS QoS problems

� Correlate with BSS GSM QoS problems

� List the probable causes of BSS GPRS QoS degradation




8

Course Objectives [cont.]






9

About this Student Guide

� Switch to notes view!Conventions used in this guide

Where you can get further information

If you want further information you can refer to the following:

� Technical Practices for the specific product

� Technical support page on the Alcatel website: http://www.alcatel-lucent.com

Note

Provides you with additional information about the topic being discussed.

Although this information is not required knowledge, you might find it useful

or interesting.

Technical Reference (1) 24.348.98 – Points you to the exact section of Alcatel-Lucent Technical

Practices where you can find more information on the topic being discussed.

WarningAlerts you to instances where non-compliance could result in equipment

damage or personal injury.




10

About this Student Guide [cont.]

� Switch to notes view!





11

Self-assessment of Objectives

� At the end of each section you will be asked to fill this questionnaire

� Please, return this sheet to the trainer at the end of the training


Instructional objectives Yes (or globally yes)

No (or globally no)

Comments

1 To be able to XXX

2

Contract number :

Course title :

Client (Company, Center) :

Language : Dates from : to :

Number of trainees : Location :

Surname, First name :

Did you meet the following objectives ?

Tick the corresponding box

Please, return this sheet to the trainer at the end of the training

��




12

Self-assessment of Objectives [cont.]


Instructional objectives Yes (or Globally yes)

No (or globally no)

Comments

Thank you for your answers to this questionnaire

Other comments

��

Section 1 � Module 1 � Page 1


3JK10237AAAAWBZZA Issue 01

Do not delete this graphic elements in here:

1�1All Rights Reserved © Alcatel-Lucent 2008

Module 1Role of the BSS in GPRS QoS Monitoring


Section 1EGPRS QoS


3FL11829ACAAZZZZA2 Issue 02





EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Role of the BSS in GPRS QoS Monitoring

1 � 1 � 2

Blank Page


First editionLast name, first nameYYYY-MM-DD01

RemarksAuthorDateEdition

Document History






1 � 1 � 3

Module Objectives

Upon completion of this module, you should be able to:

� Describe the role of the BSS in the End-user GPRS QoS and the dependencies between Global (BSS+GSS) and BSS GPRS QoS on one hand and between BSS GSM and GPRS QoS on the other hand






1 � 1 � 4

Module Objectives [cont.]







1 � 1 � 5

Table of Contents

Switch to notes view!Page

1 Distinction between BSS/BSS+GSS/End-user GPRS QoS 72 Implementation of GPRS QoS Profiles at BSS Level 133 Source of Information for GPRS QoS Monitoring 264 Dependencies between BSS GSM and GPRS QoS 365 Impact of GMM/SM Signaling on BSS QoS Interpretation 396 Indicators Classification 43






1 � 1 � 6

Table of Contents [cont.]








1 � 1 � 7

1 Distinction between BSS/BSS+GSS/End-user GPRS QoS






1 � 1 � 8


Different Levels of QoS

GGSN

GPRS GPRS BackboneBackbone

PacketPacketDataData

NetworkNetwork

Gb

SGSN

MFS

AterAbis

BSS

BSS+GSS QoS

Gn GiUmR

BSS QoS

End-user QoS

TETE

BSC

BTS

3 types of QoS are involved in the overall analysis of the GPRS QoS :

� Radio QoS

� It must be considered from the R interface to the Gb interface. It belongs mainly to the radio

environment as well as the proper functioning of the PCU implemented inside the BSS.

� It is defined in terms of throughput, service precedence, RLC reliability mode, transfer delay.

� GPRS QoS

� It must be considered from the R interface (MS access to the GPRS) to the Gi interface (exit from

the GPRS Network).

� It includes the Radio QoS and the GSS QoS.

� It is defined in terms of service precedence, transfer delay, mean and peak throughputs and

reliability.

� End-User QoS

� This is the QoS as the user feels it.

� It includes the GPRS QoS as well as the QoS of the external networks and their connection to the

GPRS GSS.

� Even if it does not belong to the operator, it should still be monitored as it can generate customer

complaints.






1 � 1 � 9


Dependencies between QoS Levels

End-user QoS

BSS+GSS QoS

BSS QoS

A bad BSS GPRS QoS (Radio QoS) will lead to a bad GPRS QoS and a bad End-user QoS.

A bad End-user performance can be due to a bad GSS behaviour without any BSS GPRS QoS degradation.

A bad End-user QoS can also be due to a bad PDN performance.






1 � 1 � 10


Impact of UE

� Different data applications are multiplexed over the GPRS radio layers: FTP, WEB/HTTP, WAP, MMS, etc.

� Data applications have very different traffic characteristics (amount of data, duration between LLC PDUs) leading to different ways of triggering radio layers algorithms

� Therefore Parameters setting in the GPRS network will lead to different performance according to the service

A bad end-user QoS can also be due to the setting of TE protocol layers parameters which can not have

optimal values to get the best GPRS performance.






1 � 1 � 11


Impact of UE: Example

� Data applications use TCP/IP protocol layers which have a great impact on the end-user QoS

(*)

First IP router Last IP router

GTP

relay

SNDCPP

BSSGPRLC BSSGP

relay

relay

SNDCPP

PPP

FTP

TCP

IP

PPP

LLC

RLC

MAC

RF

MAC

RF

NS

L1

NS

L1

LLC UDP

IP-Gn

L2

L1’

UDP

IP-Gn

L2

L1’

IP

relay

IP

GTP

IP

relay

IP

relay

IP

UmRGb

Gn GiTE (PC,PDA …)

MSBSS

SGSNGGSN

Possible repartition on the end to end path of the TCP flight size

TCP data segment

TCP acknowledgement

(*) this graphical representation is used toexpress the fact that many data segments arecurrently waiting to be transmitted on therepresented link and are stored in buffers of thedevice handling the link . It doesn’t mean thatsimultaneous segments are being transmitted.

FTP above TCP/IP layers

A bad end-user QoS can also be due to the setting of TE protocol layers parameters which can not have

optimal values to get the best GPRS performance.






1 � 1 � 12


Understand BSS GPRS QoS

� GPRS QoS is not an isolated topic:

� It is necessary to use GSM indicators in order to complete the analysis of GPRS QoS

� It is necessary to use GSM counters in order to complete the analysis of the impact of GPRS traffic on GSM QoS

� The BSS QoS does not allow to have a complete understanding of the end to end QoS seen by the user

� Indeed, upper protocol layers (TCP for example) have a great impact on the global QoS

� The GSS also has a great impact on the global QoS






1 � 1 � 13

2 Implementation of GPRS QoS Profiles at BSS Level






1 � 1 � 14

Location services• Traffic Conditions• Itineraries• Nearest Restaurant, Cinema, Chemist, Parking, ATM, etc..

Fun• Games (Hangman, Poker, Quiz, …)• Screen Saver• Ring Tone• Horoscope• Biorhythm

MediaAlways-on

M-commerce

Mobile Office• Voice (!)• E-mail• Agenda• IntraNet/InterNet• Corporate Applications• Database Access

Transportation• Flight/train Schedule

• reservation

Vertical application

• Traffic Management

• Automation

•Mobile branches

• Health

Music• Downloading ofmusic files orvideo clips

News(general/specific)• International/National News

• Local News• Sport News• Weather• Lottery Results• Finance News• Stock Quotes• Exchange Rates

Physical• on-line shopping• on-line food

Non physical• on-line Banking• Ticketing• Auction• Gambling• Best Price• e-Book

Directories• Yellow/White Pages• International Directories

• Operator Services


Data Services

Different services can be found in the 3 categories:

� Teleservices provide the full capabilities for communications by means of a terminal equipment, network functions and possibly functions provided by dedicated centers.

� Multimedia teleservices support the transfer of several types of information.

� M-commerce:

� Non-physical = electronic goods (e-banking, e-flight ticketing, etc).

� Physical = electronic payment of physical goods (food, supplies, hardware, etc).

Retrieval servicesProvide the capability of accessing information stored in data base centers. The information is sent to the user on demand only. An example of one such service in the Internet's World Wide Web (WWW).

Messaging services Offer user-to-user communication between individual users via storage units with store-and-forward mailbox, and/or message handling (e.g., information editing, processing and conversion) functions;

Conversational servicesProvide bi-directional communication by means of real-time (no store-and-forward) end-to-end information transfer from user to user. An example of such a service is the Internet's Telnet application;

Tele-action servicesCharacterized by low data-volume (short) transactions, for example credit card validations, lottery transactions, utility meter readings and electronic monitoring and surveillance systems.

Distribution servicesCharacterized by the unidirectional flow of information from a given point in the network to other (multiple) locations. Examples may include news, weather and traffic reports, as well as product or service advertisements;

Dispatching servicesCharacterized by the bi-directional flow of information from a given point in the network (dispatcher) and other (multiple) users. Examples include taxi and public utility fleet services;

Conferencing servicesProvide multi-directional communication by means of real-time (no store-and-forward) information transfer between multiple users.






1 � 1 � 15


QoS Requirements - Exercise

� Different applications require different QoS

� Exercise: find qualitatively the QoS requirements of the following data services

+: low sensitivity, ++: medium, +++: high

Service Transfer Delay Throughput Reliability

web

video streaming

ftp

location based advertising

audio streaming

email

wap

fax

e-commerce

interactive games

SMS

Data applications have very different traffic characteristics (amount of data, duration between LLC

PDUs) leading to different ways of triggering radio layers algorithms. This has a direct impact on the

follow-up of some QoS indicators at OMC-R level: number of DL/UL TBF establishment requests, DL/UL

TBF duration, coding scheme distribution.






1 � 1 � 16

� 2 R’97/98 GPRS QoS attributes supported in the Alcatel-Lucent BSS

� Precedence Class: relative importance of service under congestion; 3 values

are defined

� Reliability Class: mainly linked to Ack / Not Ack modes at RLC and LLC

levels and within the backbone network; 5 values are defined

� 4 R’99 GPRS QoS attributes supported in the Alcatel-Lucent BSS

� Traffic Class: Conversational, Streaming, Interactive, Background

� Traffic Handling Priority: From 1 (highest priority) to 3 (lowest priority)

� Guaranteed bit rate for Uplink: From 0 to 8640 kbps

� Guaranteed bit rate for Downlink: From 0 to 8640 kbps


GPRS QoS Profile

Precedence classes: high, normal, low

Delay classes:

� class 1 (average delay<0.5 s, 95% delay<1.5 s)

� class 2 (average delay<5 s, 95% delay<25 s)

� class 3 (average delay<50 s, 95% delay<250 s)

� class 4: not specified = “best effort

The Mean Throughput class range is smaller than the Peak Throughput class one because:

� The later is considered per interface (the purpose being to maximize the use of the transmission

capacity over each interface according to its physical characteristics).

� The former is considered end to end and must take into account the weaker interface characteristics,

the air interface one.

Reliability: Five classes are defined according to the tolerable BER (from 1 = lowest BER required to 5 =

highest tolerated BER and no acknowledgement or error checking).






1 � 1 � 17

� ETSI R’97 principles:

� GPRS QoS is negotiated between the MS and the SGSN, at PDP context activation

� The BSS is not involved in QoS negotiation

� But the BSS should be able to do its best...

� No absolute QoS can be guaranteed by the BSS

� The SGSN and the GGSN play the main role in QoS management

� ETSI R’99 principles

� As in R’97, the QoS negotiation is initiated by the MS at the PDP context activation

� The BSS is involved in this negotiation if EN_PFC_FEATURE= Enabled� Then a Packet Flow Context is created

� The BSS can guarantee the required QoS or downgrade to Best Effort

� E.g. in case of lack of resource


ETSI Principles






1 � 1 � 18


QoS Profile at BSS Level

GGSN

GPRS GPRS BackboneBackbone

PacketPacketDataData

NetworkNetwork

Gb

SGSN

MFS

AterAbis

BSS

GPRS QoS

Gn GiUmR

Radio QoS

End-user QoS

TETE

BSC

BTS

Throughput: not managed by Alcatel-Lucent BSS. Best effort is supported.

Service precedence: partly managed by Alcatel-Lucent BSS.

RLC reliability mode: managed by the BSS.

Transfer delay: not managed by Alcatel-Lucent BSS. Best effort is supported.

See next pages for details.






1 � 1 � 19


Precedence

� Precedence:

� Defines the priority for maintaining service in a congestion situation

� Specified on:

� The DL path: in the DL BSSGP PDU header

� The UL path: radio priority in “Packet resource request” (2-phase access)

� If EN_PFC_FEATURE=Disabled� Not managed in the Alcatel-Lucent BSS, but the operator can configure, in case of GPRS cell configured with a Master PDCH the persistence level of each radio priority and therefore control the uplink TBF establishment delay

� If EN_PFC_FEATURE=Enabled� The precedence is taken into account for the Interactive and Background classes

� It impacts the way of scheduling the RLC data blocks at MS and TRX level (Weighted Round Robin algorithm)

Service precedence:

� The management of the persistence levels in the Alcatel-Lucent BSS is the following. When there is a

PBCCH allocated in the cell, the MFS broadcasts on the PBCCH four persistence levels P(i), defined by

O&M, each of them corresponding to a given radio priority i (i = 1, 2, 3, 4), where P(i) ∈{0, 1, …14, 16}. For each access attempt, the MS draws a random value R in the set {0, 1, …14, 15}. The MS is allowed to send a Packet Channel Request message only if the P(i), where i is the radio priority of the TBF being

established, is lower or equal to R. This method allows the operator to differentiate the access

probability of the MSs as a function of their radio priority.

� There is no preemption of an on-going TBF to establish a new one with a higher service precedence

level.






1 � 1 � 20


Reliability

� Reliability:

� Defines the transmission characteristics that are required by an application in terms of SDU loss probability, duplication of SDU, mis-sequencing of SDU or corruption of SDU

� Implemented at BSS level as RLC Acknowledged (Ack) mode or RLC Not acknowledged (Nack) mode

� Specified on

� The DL path: in the DL BSSGP PDU header

� The UL path: in “Packet resource request” (2-phase access)

� Default mode: Ack






1 � 1 � 21


Traffic class with EN_PFC_FEATURE=Enabled

� Conversational class (not supported)

� Video conference

� Streaming class

� Live video retransmission

� The MFS reserves radio and transmission resources at the PFC creation

� Interactive class

� Web browsing

� No resource reservation

� RLC data blocks are scheduled with a certain priority

� Background class

� email, FTP

� No resource reservation

� RLC data blocks are scheduled with a low priority

Delay

sensitive

+

-

Data

Integrity

sensitive

-

+

Conversational class:

� The most well known use of this scheme is telephony speech (e.g., GSM). But with the Internet and

multimedia, a number of new applications will require this scheme, for example voice over IP and video

conferencing tools.

� Real-time conversation is always performed between peers (or groups) of live (human) end users. This

is the only scheme where the required characteristics are strictly given by human perception.

Streaming class:

When the user is looking at (listening to) real time video (audio) the scheme of real time streams applies.

The real time data flow is always aiming at a live (human) destination. It is a one way transport.

Interactive class:

� When the end user, that is either a machine or a human, is on line requesting data from a remote

equipment (e.g., a server), this scheme applies.

� Examples of human interaction with the remote equipment are: web browsing, data base retrieval,

server access. Examples of machines interaction with the remote equipment are: polling for

measurement records and automatic data base enquiries (tele-machines).

Background class:

� When the end user, that typically is a computer, sends and receives data files in the background, this

scheme applies.

� Examples are background delivery of E-mails, SMS, download of databases and reception of

measurement records.






1 � 1 � 22


Traffic Handling Priority

� THP:

� From 1 (highest priority) to 3 (lowest priority)

� THP1

� THP2

� THP3

� The THP is associated only with the Interactive class (if EN_PFC_FEATURE=Enabled)

According to 3GPP TS 23.107, the Traffic Handling Priority specifies the relative importance for handling of

all SDUs belonging to the bearer compared to the SDUs of other bearers.






1 � 1 � 23


Guaranteed Bit Rate

� UL/DL Guaranteed bit rate (R’99)

� From 0 to 8640 kbps

� 3 ranges are usable with 3 different step sizes

� The Guaranteed Bit Rate (GBR) is associated with the Streaming class, if � EN_PFC_FEATURE = Enabled at BSC level

� and EN_STREAMING = Enabled at cell level

64 kbps8640 kbps576 kbps

8 kbps568 kbps64 kbps

1 kbps63 kbps0 kbps

Step sizeMaxMin

According to 3GPP TS 23.107, the Traffic Handling Priority specifies the relative importance for handling of

all SDUs belonging to the bearer compared to the SDUs of other bearers.






1 � 1 � 24


Alcatel-Lucent QoS Offer - R’97/98 QoS Compliance

BE = Best-Effort

ETSI R’97/98 QoS attributes Alcatel-Lucent Offer

Precedence class Mean throughputclassDelay class Resulting QoS class

(4) Best Effort

1, 2 or 3

1,. 2 or 3

1,. 2 or 3

1,. 2 or 3

any

(3) Low priority

Normal, High priority

(2) Normal priority

(1) High priority

any

any

Best Effort

specified, except BE

specified, except BE

Best-Effort

Best-Effort

Best-Effort

Normal

Premium

Reliability class: as required by the MS

The QoS attributes are associated with a PDP context performed by an R’97/98 MS.

The five QoS parameters of the standard define more than 60 combinations! This is too much and must be simplified:

� Too complex to implement,

� Many of the combinations have no meaning!

� The standard "allows" simpler QoS implementations.

� “-” = any value.

� In green, the main criterion for the definition of the resulting QoS.

Alcatel-Lucent implementation: 3 QoS classes are defined:

� Best effort: Inexpensive, comparable to the Internet (no commitment). Ideal for foraging on the internet.

� Normal: Comparable to an intranet.

� Premium: Expensive, high performance.






1 � 1 � 25


Alcatel-Lucent QoS Offer - R’97/98 QoS Mapping into R'99 QoS

� There is a mapping between R'99 Traffic class and Alcatel-Lucent QoS class

Traffic handling priorityR'99 Traffic class R’97/98 Bearer QoS class

Premium

Premium

Premium

Normal

Normal

Conversational

Streaming

Interactive

Interactive

Interactive

-

-

1

2

3

Best EffortBackground -

The mapping of R’97/98 QoS attributes to R'99 QoS is applicable in the following cases:

� hand-over of PDP context from GPRS R’97/R'98 SGSN to GPRS R'99 or UMTS SGSN.

� when an R'99 MS performs a PDP context activation in an R'99 SGSN with an R'97/98 GGSN.

When GGSN responds to the PDP Context Activation, mapping of the changed R97/98 QoS attributes

received from the GGSN to R99 QoS attributes is performed in the serving SGSN.

� when the SGSN has received an R’97/98 QoS subscribed profile, but the MS is R'99.

The mapping of R'99 QoS attributes to R'97/98 QoS is applicable in the following cases:

� the PDP context is handed over from GPRS R'99 to R'97/R'98.

� when an R'99 MS performs a PDP context activation in an R'99 SGSN while the GGSN is R'97/98.

In this case the SGSN shall perform mapping of the R99 QoS attributes to the R97/98 QoS attributes;

� when the SGSN sends user data to the BSS for an R'99 MS.

� when the SGSN has received R'99 QoS subscribed profile but the MS is R'97/98.

� in the new SGSN, during an inter-SGSN RA_update procedure, or an inter-system change, on receipt of

the R'99 QoS attributes from the old SGSN.






1 � 1 � 26

3 Source of Information for GPRS QoS Monitoring






1 � 1 � 27


PM Counters

PacketPacket

DataData

NetworkNetworkGPRS GPRS

BackboneBackboneSGSN GGSN

Gb

MFS BSC

HLR

COUNTERS

PM counters retrieval and post-processing is the cheapest solution.






1 � 1 � 28


Trace User Data Transfer

� Transmission plane

RLC

MAC

RLC

MACL2

L1

MS BSS SGSN GGSNUm Gb Gn

L1bis

IP / X.25

GTP

UDP/TCP

IP

L1

SNDCP

LLC

BSSGP

NS

GTP

UDP/TCP

IP

L2NS

L1bisGSM-RF

RRM

Application

IP / X.25

SNDCP

LLC

RRM

GSM-RF

BSSGPRelay

Relay

NS

L1bis

BSSGPRRM

L2-(M)EGCH

L1-GCH

L2-(M)EGCH

BTS MFSAbis Ater(mux)

GSM-RFL1-GCH

RLC

MACRelay

RelayRelay

Air tra

ces

GCH tra

ces

Gb tra

ces

Interfaces traces are of good complementary information but expensive:

� used for problem investigation

� used when lack of PM counters






1 � 1 � 29


Trace Signaling

� Signaling plane with CCCH use

L1

SGSN Gn GGSN

RRM

MS Um BSS Gb

GSM-RF GSM-RF L1bis L1bis

IP

L1

IP

NS NS L2 L2

BSSGP BSSGP

BSCGP / RRM

LLC LLC UDP UDP

GMM/SM GMM/SM GTP GTP

Relay

Relay

BSCGP

BSSGP

NS

L1bisL2-GSL

L1-GSL

RR BSCGP

MFSAbis

L2-RSL

L1-RSL L1-GSL

BSC Ater(mux)

L2-RSL

L1-RSL

L2-GSL

BTS

GSM-RF

Relay

Relay

BSC Relay

Air tra

ces

GSL tra

ces

Gb tra

ces

GCH tra

ces

2 GSL at 64Kbit/s per GPU

RSL: refer to the Dimensioning rules for GSM






1 � 1 � 30


End-User QoS

� End-user performances are obtained through measurements carried out for different end-user services:

� Ping

� FTP

� WAP

� WEB (HTTP)

� Traces must be performed at both Air interface and Application levels

� These performances must be interpreted with a maximum of information concerning the context of the measurements

� Use of a database to register performance results

FTP tests:

� Static cell measurements:

� DL transfer of an uncompressible file of 500 KB size

� UL transfer of an uncompressible file of 200 KB size

� Drive measurements:

� DL transfer of an uncompressible file of 1MB minimum size

� UL transfer of an uncompressible file of 200 KB minimum size

PING Tests: Series of 100 pings

HTTP tests: Static cell and drive measurements:

� HTTP browsing of an html page of 400 KB minimum size






1 � 1 � 31


End-User QoS Measurements Principles

� GPRS performance tests performed

� with PDN (real end-user QoS)

� without PDN (BSS+GSS QoS: use of a local server on the Gi interface just after the GGSN)

� Use of a too old or too new mobile can be risky

� Reference mobiles are Nokia N95 for B10 features

� Use of the NEMO software (Anite)

� to pick up the transferred frames

� to calculate the throughput at RLC layer

� to monitor lower layers

� Use of Wireshark software

� to detect IP retransmissions, TCP lost frames, …

� to monitor application layers (IP, FTP, etc.)

� Use of database to register performance results

NOKIA 6220 and 6230 are EDGE mobiles.

Tests configuration set-up needs some specific data for like:

� APN of the operator to be declare in the Properties of the Modem connection on client PC (the one

with Agilent NITRO installed)

� IP address of the Internet/WAP gateway or of the Application server connected to GGSN

� DNS server address if necessary

� user name and password for GPRS connection

� Name or the URL of the WEB page to be downloaded for HTTP tests






1 � 1 � 32


End-User QoS Measurements Results

� Applications server accessibility (PING)

� Server accessibility success rate

� Round Trip Time (RTT) in seconds per ping command

� FTP

� FTP session success rate

� Application layer throughput in kbit/s per file

� WAP

� WAP gateway access time

� WAP page download success rate

� Application throughput

� HTTP (WEB)

� WEB page download success rate

� Application throughput

MMS tests:

� MMS emission success rate

� MMS notification success rate

� MMS reception success rate

� MMS time to send

� Time to receive the MMS notification

� Time to retrieve the MMS

Optional RLC/MAC statistics during end-user QoS tests:

� CS distribution : % of CSx RLC blocks and total time of CSx usage

� CS changes: number of CS changes per minute

� Retransmissions: % of RLC blocks retransmitted

� BLER: % of RLC blocks in error

Usually QoS indicators giving throughput or time values are provided with 4 detailed indicators:

� minimum

� maximum

� average

� standard deviation






1 � 1 � 33


GSS QoS

� Counters:

� in the SGSN

� in the GGSN

� in the HLR

� Traces:

� BSS-SGSN interface (Gb)

� GGSN-PDN interface (Gi)

� intra-GSS interface (Gn)






1 � 1 � 34


BSS QoS

� Counters:

� in the MFS (specific to GPRS)

� in the BSC (in relation to GSM)

� Traces:

� Air interface (Um)

� Ater interface (GCH)

� MFS-BSC interface (GSL)

� BSS-SGSN interface (Gb)

Tool chain = OMC-R + NPO

Trace MS + NEMO

Protocol analyzer + COMPASS(K12 Viewer)






1 � 1 � 35


BSS QoS Measurements Principles

BTS

Internet/Intranet

SGSN GGSNMFSBSCFirewall

OtherPLMNPacket domain

Core network

GnGbAterAbis

IP layer

Application layer SERVERe.g.

FTP, HTTP

Measurement

LLC layer

BTS

Internet/Intranet

SGSN GGSNMFSBSCFire-wall

OtherPLMNPacket domain

Core network

GnGbAterAbis

Physical layer

RLC/MAC layer

SERVERe.g.

FTP, HTTP

Measurement Trace SWAnite NEMO

Application

Presentation

Session

Physical

Transport

Data Link

Network

Protocol Analyzer K1205

AMI Compass GNNettest

OMC-R network statisticswith OMC-R network counters

Gb Statistics

GPRS Air Interface Statistics

EGPRS MSNOKIA N95

OSI Layers

For the Air interface trace:

� Use of a too old or too new mobile can be risky

� Reference mobiles are Sagem (OT290), Motorola (T280), NOKIA ( 6230)

� Use of a PC preferably with Windows 2000

� Use of the Agilent software E6474A Nitro

� Use of end-user QoS monitoring tool (DEUTRIP, DMS)

For the GCH, GSL, Gb interface trace:

� Use of a protocol analyzer with the Alcatel-Lucent BSCGP stack

� The reference analyzer is Tektronix K1205 v2.40

� Use of a post-processing tool

� The reference tool is COMPASS GPRS






1 � 1 � 36

4 Dependencies between BSS GSM and GPRS QoS






1 � 1 � 37


Impacts

GSM QoS

GPRS QoS

Bad radio conditions like coverage or interference problems degrading GSM QoS also provoke BSS GPRS

QoS problems.

Bad BSS GPRS performance is not always correlated to GSM QoS problems:

� Congestion can be due to a lack of resource specific to GPRS.

� A low throughput can be due to a bad setting of radio algorithms specific to GPRS.

On the other hand GPRS traffic can induce or worsen GSM QoS performance:

� PS traffic can increase CS congestion.

� PS signaling using CCCH channels can induce a PS AGCH and/or PCH overload and eventually an SDCCH

congestion.






1 � 1 � 38


Exercise

� Among the following list of typical problems in a GSM network, find the ones having an impact on BSS GPRS QoS

Typical BSS GSM problem Impact on BSS GPRS QoS

Coverage

Interference

path unbalanced at cell fringe

TRX HW degradation

Abis MW problem

A interface congestion

SDCCH congestion

TCH congestion

Rate of LU/call too high

Handover failure too high

Time allowed:

10 minutes






1 � 1 � 39

5 Impact of GMM/SM Signaling on BSS QoS Interpretation






1 � 1 � 40


GPRS Protocol Layers

Physicallayer

L2-GCHL1-GCH

MS BTS MFS SGSN

relay

relayBSSGP

Um Abis/Ater Gb

Physical

layerPhysicallayer

Frame

relay

RLC

L2-GCHL1-GCH

MACMAC

RLC

Physicallayer

Frame

relay

BSSGP

PCU

IP

LLC

GMMSNDCP SM

LLC

SNDCPSMGMM

User data in IP packets

SM signaling messages

GMM signaling messages

LLC frames

For a PS service the BSS simply relays the LLC frames between the MS and the SGSN. GPRS GMM/SM

signaling messages are transferred through the BSS as User data.

Therefore a BSS Data transfer procedure (called TBF) is carried out either to transfer user data or to

transmit MS-SGSN signaling message. BSS GPRS QoS indicators have to be carefully interpreted especially

in the case of a high load of GPRS signaling.

BSS GPRS Protocol (BSSGP)

Its function is to relay LLC frames over the Gb interface, with no guarantee of integrity (relaying user

data and GMM / SM messages: session, RA_update and paging procedures).

There is 1 BSSGP frame for 1 LLC frame.






1 � 1 � 41


GMM/SM Signaling Load

� There are a lot of GPRS signaling message in case of:

� cell update

� RA update (Normal, Periodic)

� There are less GPRS signaling message in case of:

� GPRS attach

� GPRS detach

� PDP context activation

� PDP context de-activation

BSS GPRS QoS indicators must be carefully interpreted knowing that TBFs are used for both data and

signaling transfer.

Gb traces might be needed for a better understanding of QoS problems.






1 � 1 � 42

6 Indicators Classification






1 � 1 � 43


QoS Family

� Traffic Load

� Quality Of Service

Evaluation of the rate of success or failure per interface:

� (Radio, AterMux, Gb)

or per telecom procedure:

� TBF UL/DL establishment, UL/DL Data transfer, radio resource allocation or re-allocation

� Resource Availability and Usage

� Abis interface (abis nibbles)

� AterMux interface (GCH, LapD)

� Gb interface (PVC, Bearer Channel)

� GPU object (CPU and DSP usage)






1 � 1 � 44


QoS Sub-families

GPU






1 � 1 � 45

Self-assessment on the Objectives

� Please be reminded to fill in the formSelf-Assessment on the Objectivesfor this module

� The form can be found in the first partof this course documentation






1 � 1 � 46


Exercise

� A customer complains about the fact that transferring a file from his laptop to his home computer using GPRS connected to internet takes too much time.

� What will you do if you have to investigate this customer complaint?

Time allowed:

10 minutes






1 � 1 � 47

End of ModuleRole of the BSS in GPRS QoS Monitoring






Module 2Recalls on the Main BSS GPRS Telecom Procedures


Section 1EGPRS QoS







EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Recalls on the Main BSS GPRS Telecom Procedures

1 � 2 � 2

Blank Page




Document History






1 � 2 � 3

Module Objectives


� Describe the main BSS GPRS procedures and algorithms having an impact on QoS






1 � 2 � 4








1 � 2 � 5

Table of Contents


1 GPRS Logical Channels 72 TBF: Data Transfer Procedure between the MS and the BSS 93 Gb: BSSGP Protocol and Frame 17






1 � 2 � 6









1 � 2 � 7

1 GPRS Logical Channels






1 � 2 � 8

1 GPRS Logical Channels

Organization

PDCH

Master PDCH Slave PDCH

PBCCH PCCCH

PDTCH PACCH

PTCH PTCCH

Primary MPDCH

PPCH PAGCH

Secondary MPDCH

physical channel

control channel

traffic channel

signaling associated control channel

logical channel category

logical channel






1 � 2 � 9

2 TBF: Data Transfer Procedure between the MS and the BSS






1 � 2 � 10


Radio Resources

� Temporary Block Flow (TBF): unidirectional flow of data between the MS and the MFS for the transfer of one or more LLC PDUs

� Radio resources allocated to a TBF are:

� DL TBF

� UL TBF

PDCH 1

B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11

PDCH 2

B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11

PDCH 3

B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11

TBF with TFI = 5 TBF with TFI = 17 TBF with TFI = 24

A Temporary Block Flow is a temporary, unidirectional physical connection across the Um interface,

between one mobile and the BSS. The TBF is established when data units are to be transmitted across

the Um interface. It is released as soon as the transmission is completed.






1 � 2 � 11


TBF Phases

� The TBF procedure can be split as represented below

� During an on-going TBF (progress) in one direction, a TBF in the other direction can be established quicker than usually

establishment progress release

Radio resources to be

used during the data

transfer are reserved by

the BSS and are assigned

to the MS

Data transfer through

RLC blocks

transmission

Radio resources are

freed






1 � 2 � 12


UL TBF, Delayed Final PUAN without Extended UL TBF

� In order to establish a DL TBF faster the release of a UL TBF can be delayed

� is the time during which a DL TBF can be established using the UL TBF radio resources before they are freed T_DELAYED_FINAL_PUAN

UL TBF

establishment progress release

T_DELAYED_FINAL_PUAN

default: 400ms






1 � 2 � 13


UL TBF, Delayed Final PUAN with extended UL TBF

� Extended UL TBF mode

� UL TBF is maintained during after the last block ( CV=0) has been acknowledged

releaseTBF active TBF extendedTBF establishment

UL TBF

T_MAX_EXTENDED_UL

default : 2 seconds

T_MAX_EXTENDED_UL






1 � 2 � 14


DL TBF, Delayed DL TBF Release

� The release of a DL TBF is delayed after all the DL RLC blocks have been transferred in order to be able to:

� establish a UL TBF faster

� resume the DL data transfer (new LLC PDU coming from the SGSN) without having to establish a new DL TBF

DL TBF

progress release

T_NETWORK_RESPONSE_TIME

default : 1.6 seconds

TBF active TBF delayed






1 � 2 � 15


DL TBF, Fast Establishment

� A DL TBF can be re-established faster during a short time after a DL TBF release using the radio resources of the previous TBF

� It is possible because the MS still monitors the radio resources during timer after the DL TBF has been released

DL TBF

release

T3192

default : 500ms

TBF active TBF delayed

Fast DL TBF establishment

on PACCH

possible

T3192






1 � 2 � 16


DL TBF, Establishment in DRX Mode

� After T3192, a DL TBF has to be established on Control Channels:

� faster during DRX_TIMER_MAX when the MS is in Non-DRX mode

� slower afterwards when the MS is in DRX mode

DL TBF

TBF release

DRX_TIMER_MAX

default : 2 seconds

TBF active

TBF delayed

T3192

on PCH of MS paging group

DL TBF establishment

possible

on AGCH,

or PCH of MS paging group






1 � 2 � 17

3 Gb: BSSGP Protocol and Frame






1 � 2 � 18


L1bis

� Bearer Channels: consecutive n timeslots of a 2Mb/s link

� with n = 0 … 31

L1

NS (SNS)

NS (NSC)

BSSGP

MFS

L1

NS (SNS)

NS (NSC)

BSSGP

SGSN

Gb interface

PCM BC i

BC j

PCM

BC y

BC x

The Gb physical interface is made up of one or more 64-Kbit/s channels on one or more physical lines at

2048 Kbit/s.

Both individual 64-Kbit/s and n*64-Kbit/s channels are supported by the MFS.

A Bearer Channel (BC) is an n*64-Kbit/s channel (1 ≤ n ≤ 31).

NB: among the 16 PCM links offered per PCU, only 8 are dedicated to the Gb interface, 4 for the upload and 4 for the download. The maximum point-to-point transfer capacity over the Gb interface in one

direction is then 31*64 Kbit/s*4 = 8192 Kbit/s.






1 � 2 � 19


Network Service

� The Sub-Network Service (SNS):

� Routing of the BC onto the Frame Relay, thanks to Permanent Virtual Connections (PVC)

� Only 1 PVC per BC

L1

NS (SNS)

NS (NSC)

BSSGP

MFS

L1

NS (SNS)

NS (NSC)

BSSGP

SGSN

Frame Relay NetworkPVCaDLCIx

PVCmDLCIαααα

PVCbDLCIy

PVCnDLCIββββ

Gb interface

Concept of PVC:

� A PVC is a synchronous access line, semi-permanent connection.

� The PVC allows the multiplexing on a BC.

� It is not an end to end link between the MFS and the SGSN.

� At MFS side a PVC is identified by its Data Link Connection Identifier (DLCI) which is

independent from the one defined at SGSN side. DLCI 0 is used for signaling.

� There is one PVC per BC.

The SNS layer, layer 2.1 in the OSI model, offers the Frame Relay technology. The NSC layer, layer 2.2 in

the OSI model, offers the point to point data transfer in both directions.

The PVC standards are not specific to GPRS. Please refer to the « Frame Relay Forum » organization, the

ITU-T and ANSI (T1S1.1 workshop) specifications.






1 � 2 � 20


Network Service [cont.]

� The Network Service Control (NSC)

� Manages n Virtual Connections (NS-VCs) per GPU, with 2 ≤ n < 120

� Share the load within 1 GPU

L1

NS (SNS)

NS (NSC)

BSSGP

MFS

L1

NS (SNS)

NS (NSC)

BSSGP

SGSNNSVC

NSVCi=11

NSVCNSVCi=12

Gb interface

Concept of NS-VC:

� A NS-VC is an end to end logical link between the MFS and the SGSN.

� Each NS-VC is identified by its NSVCI which has an end to end significance on the Gb interface.

� There is a one to one relation between one NS-VC and one PVC.

� Sub-network service function: ordered data transfer.

The main functions of the NSC layer (2.2 layer) are: sequencing of the data transmission, flow control,

lost frame management.

When a MS performs a GPRS ATTACH, it is allocated on one NS-VC and only one. There is no change of NS-

VC afterwards, until cell reselection or GPRS DETACH.






1 � 2 � 21


Network Service [cont.]

� Concept of Network Service Entity (NSE):

� 1 NSE groups several NS-VCs (≥ 2 NS-VCs per NSE)

� � 1 NSE = 1 GPU

� The NSE is identified by an NSEi which has an end-to-end significance over the Gb interface

� Load sharing: the NS-VCs of the NSE are shared among the BVC's associated to the NSE

NSVCNSVCi=11

NSVCNSVCi=12L1

NS (SNS)

NS (NSC)

BSSGP

PCU

NSENSEi = 1

Note: for MM purposes, the SGSN needs a 1:1 correspondence between the NSEI and the RAI.

Physical layer

SNS sub-layer

NSC sub-layer

BVCBSSGP layer

Cell

BSS

BVC

Cell

2 Mbit/s

BC BC

PVC PVC

NS-VC NS-VC

NSE

BVC

Cell

BVC

Cell

2 Mbit/s

BC BC

PVC PVC

NS-VC NS-VC

NSE






1 � 2 � 22


BSSGP

� BSSGP Virtual Connection (BVC)

� End-to-end link between the MFS and the SGSN

� 1 BVC = 1 cell

� n BVC within 1 GPU

SNS

NSC

BSSGP

SGSN

L1

SNS

NSC

BSSGP

MFS

L1

Gb interface

NSVC

BVCi=1BVCi=2

BVCi=nBVCi=1

BVCi=2

BVCi=n

Two types of BVC:

� point-to-point BVC dedicated to the PS traffic of one cell (BVCi ≠ 0).

� signaling BVC (BVCi=0) which is the signaling circuit of all the point to point BVCs of one NSE

(GPU).

For NM reason, the duplet BVCi/NSEi must be unique within an SGSN.

To activate a new cell in an SGSN, it is only needed to add a new BVCi in an NSEi. No update of the NSEi

information is necessary.






1 � 2 � 23

NSE2

SGSN

NSE1NSE1

NSE2

F.RF.RNetworkNetwork

PCM


Gb Interface - Manageable Entities

PCM

PCM

BVCI=2

BVCI=1

BVCI=3

BVCI=5

BVCI=6

BVCI=4

BSC1

BSC2

GPRS Core Network sideBSS side

BC PCMBCPVC

BC BCPVC

NSVC1

NSVC2

PCM

PCM

PCM

BC PCMBCPVC

BC BCPVC

NSVC3

NSVC4

BVCI=2BVCI=2

BVCI=1BVCI=1

BVCI=3BVCI=3

BVCI=5BVCI=5

BVCI=4BVCI=4

BVCI=6BVCI=6

Number of PDCH per GP board in the MFS Evolution B10:

(note 1 and note 2: with Gb over IP only)






1 � 2 � 24


Gb Interface - Protocol Model and Entities

SGSNPacket Control Unit function

(PCU)

BSS GPRS Protocol

(BSSGP)BSS GPRS Protocol

(BSSGP)

Network Service Control

(NSC)Network Service Control

(NSC)

BVCI=2BVCI=2

BVCI=1BVCI=1

BVCI=3BVCI=3

BVCI=5BVCI=5

BVCI=6BVCI=6

BVCI=4BVCI=4

BSC1

BSC2

GPRS Core Network sideBSS side

Sub-Network Service

(SNS)

Physical layer

Sub-Network Service

(SNS)

Physical layer

Frame Relay

BVC

NS-VCNSE

PVCBC

Dimensioning rules MFS Evolution B10:

Note 1:Both maximum number of E1 and maximum number of GP for stand-alone MFS cannot be reached simultaneously. The operator has to make the following choice at commissioning:

- 16 E1 with up to 8 GP with one shelf and up to 16 GP with two shelves.

- 12 E1 with up to 9 GP for the first shelf and up to 21GP with two shelves.

Note 2: In case of MFS in centralized clock mode, two 2 E1 ports are reserved for clock distribution. In this case the maximum number of E1 is reduced to 14.






1 � 2 � 25


BSSGP Frame

� One BSSGP PDU includes one and only one LLC PDU

GPRS Traffic or signalingTLLIBVCI

LLC frame

BSSGP frame

LLC header

BSSGP header

LLC payload

In case of data traffic the LLC PDU contains an SNDCP PDU.

In case of signaling, the LLC PDU contains a GMM or an SM message.






1 � 2 � 26









1 � 2 � 27

End of ModuleRecalls on the Main BSS GPRS Telecom Procedures






Module 3Description of the Main BSS GPRS QoS Counters and Indicators


Section 1EGPRS QoS







EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Description of the Main BSS GPRS QoS Counters and Indicators

1 � 3 � 2

Blank Page




Document History






1 � 3 � 3

Module Objectives


� Interpret the BSS GPRS QoS indicators attached to each BSS GPRS procedure or algorithm having an impact on QoS

� Interpret the BSS GPRS PM counters used in the computation formulae of QoS indicators






1 � 3 � 4








1 � 3 � 5

Table of Contents


1 Data Transfer Establishment 72 Data Transfer Progress 563 Data Transfer Release 884 MS Sessions / Transfers 1185 Resource Usage 1276 CS and MCS Adaptation 1657 Cell Reselection 179






1 � 3 � 6








1 � 3 � 7

1 Data Transfer Establishment






1 � 3 � 8


TBF Establishments

Data Transfer establishment

UL TBF establishment DL TBF establishment

MS in PIM MS in PTM

(DL TBF)

MS in PIM MS in PTM

(UL TBF)

MS in MM Ready state MS in MM Standby state

MS in MM Ready state

on CCCH

2-Phase

on CCCH

Non-DRX

UL TBF running

DL TBF running T3192

running

1-Phase

PS Paging

DRX

on PACCHon PACCH

oror or

There are 3 types of UL TBF establishment:

� 1-phase access on CCCH : when the MS is in Packet Idle Mode and the MS does not need more than 1 PDCH and wants to transfer blocks in RLC acknowledge mode.

� 2-phase access on CCCH : when the MS is in Packet Idle Mode and the MS needs more than 1 PDCH or wants to transfer blocks in RLC unacknowledge mode.

�During a DL TBF: when the MS is in Packet Transfer Mode in DL.

There 4 types of DL TBF establishment:

� On CCCH DRX mode: when the MS is in Packet Idle Mode and the MS is listening to all PCH channels of its CS paging group.

� On CCCH Non-DRX mode: when the MS is in Packet Idle Mode and the MS is listening to all AGCH channels.

�During a UL TBF: when the MS is in Packet Transfer Mode in UL.

� When T3192 is running: when a DL TBF has been released at the MS side and before the previously used radio resources are released (at T3192 expiry).






1 � 3 � 9

P49


UL TBF Establishment 1-Phase Access on CCCH, Success

MS BTS BSC MFS

TA calculationRACH Channel request (TA)

(EGPRS Packet)

Channel request

AGCH

Immediate assignment

Channel assignment UL (IA)PDCH, TFI, USF, TAI, TA, CS

(MCS, EGPRS window size) MS switches

on assigned

PDCH USF Scheduling

PDTCH

USF Scheduling

RLC data block

PACCH

Packet UL Ack/Nack

PDTCH

TLLI, TFI

T_USF_Scheduling_AGCHexpiry

P62c

P30cContention

resolution

T_GPRS_ASSIGN_AGCH

RLC data block

TLLI, TFI

Packet UL Ack/Nack

P62d

GPRS EGPRS

P30d

GPRS EGPRS

GCH allocation

Channel required

(TA)

Imm. assign. command

In case a Channel Request or an EGPRS Packet Channel Request is received from the mobile station, an Immediate Assignment message is sent to the MS assigning the radio resources (the PDCH id, the USF value, the TFI value, the TAI value).

In case a Channel Request is received on a RACH, the BSS does not know the multislot class of the MS. Consequently, the Alcatel BSS assigns only one PDCH to the MS.

In case an EGPRS Packet Channel Request message is received from the mobile station, the EGPRS multislot class of the MS is known by the BSS. However only one PDCH is allocated due to the limitation of the Immediate Assignment message:

� If the PDCH is allocated on a non-EGPRS capable TRX an Immediate Assignment message in GPRS mode is sent to the MS including the PDCH id, the USF value, the TFI value, the TAI value, the TA value, and the GPRS coding scheme to be used.

� If the PDCH is allocated on an EGPRS capable TRX, an Immediate Assignment message in EGPRS mode TA value and the EGPRS modulation and coding scheme to be used.

Timers

� T_USF_scheduling_AGCH: Time between the sending of the Assignment Command message to the BTS and the scheduling of the first UL block on the PDCH. This internal MFS timer is always expiring in order to leave time to the MS to switch from a CCCH to a PDCH time slot.

� T_GPRS_ASSIGN_AGCH – T_USF_scheduling_AGCH: Started at T_USF_scheduling_AGCH expiry, stopped when receiving the first UL block from the MS.

� T_GPRS_ASSIGN_AGCH = 0.8 s (default value) but computed as a function of the CCCH configuration in the cell. It cannot be set at the OMC-R level.

� T_USF_scheduling_AGCH = 0 ms (default value). It cannot be set at OMC-R level.

� T_GPRS_ASSIGN_AGCH" is the HMI name of "T_ul_assign_ccch" present in BSS telecom parameters catalogue

A contention resolution procedure is used in order to avoid that two MSs sending a Channel Request at the same time use the same allocated radio resource to send data:

� Each MS sends its TLLI in the first RLC Data Block.

� The TLLI of the MS chosen by the BSS is present in the Packet UL Ack/Nack from the MFS.

� The other MS will stop using the radio resource when receiving the Packet UL Ack/Nack with another TLLI.






1 � 3 � 10


UL TBF Establishment 2-Phase Access on CCCH, Success

MS BTS BSC MFS

RACH

Channel request

(TA)

(EGPRS Packet)

Channel request

AGCHImmediate assignment PDCH id, TBF starting time,

TA, 1 (multiple) block(s)

MS switches

on assigned

PDCHs

PACCHPacket resource request

Packet UL assignmentPACCH

Packet resource request

Packet UL assignmentTLLI, PDCHs, USFs, TFI, TAI, TA, CS

(MCS, EGPRS window size)

PDTCHUSF Scheduling USF Scheduling

TLLI, MS Radio Access Capability, QoS

(Additional Radio Access Capability)

RLC data block

PDTCH

P49

T_GPRS_ASSIGN_AGCH

T_ACK_WAIT

Contention

resolution

RLC data block

MS switches

on allocated

RLC block(s)

T3168

P62c P62d

GPRS EGPRS

P30c P30d

GPRS EGPRS

GCH allocation

GCH allocationTA calculation

Channel required

(TA)

Channel assignment UL (IA)Imm. assign. command

A 2-phase access is initiated in one of the following cases:

� When a GPRS MS wants to use the TBF to send user data in RLC unacknowledged mode.

� When a GPRS or EGPRS MS wants to precise QoS parameters (e.g., Peak_Throughput_Class, Radio_Priority).

� When a GPRS MS wants to provide the BSS with its multislot class in case of an uplink access done on CCCH.

� When an GPRS MS wants to establish the TBF to send user data in RLC acknowledged mode and the amount of data to send takes more than 8 RLC/MAC blocks (Note 1 and Note 2).

� If the EGPRS PACKET CHANNEL REQUEST is not supported in the cell (Note: the Alcatel BSS always supports the EGPRS PACKET CHANNEL REQUEST), when an EGPRS MS wishes to send user data or signaling data.

� If the EGPRS PACKET CHANNEL REQUEST is supported in the cell, when an EGPRS MS wants to use the TBF to send user data in RLC unacknowledged mode.

� If the EGPRS PACKET CHANNEL REQUEST is supported in the cell, when an EGPRS MS wants to establish the TBF to send user data in RLC acknowledged mode and the amount of data to send takes more than 8 RLC/MAC blocks (Note 3 and Note 4).

Note 1: The number of blocks must be calculated assuming channel coding scheme CS-1.Note 2: The mobile station can also request a 1-phase access.Note 3: The number of blocks must be calculated assuming modulation and channel coding scheme

MCS-1.Note 4: If the cell is EGPRS capable, the mobile station can also request 1-phase access.

The MS Radio Access Capability IE includes the Multislot class of the MS as well as the QoS required for the transferTimers� T_GPRS_ASSIGN_AGCH, controls the duration between (EGPRS Packet) Channel Request message and the UL radio block allocated to the MS.� T_ACK_WAIT: Started when the first UL block is scheduled to the MS, stopped when receiving the first UL block.

� T_ACK_WAIT = 1.2 s (default value). It cannot be set at OMC-R level.� T3168: MS timer started when sending the Packet Resource Request message and stopped when receiving the Packet UL Assignment. It is broadcast in the SI13 message.

� T3168 = 1 s (default value). It can be set at the OMC-R level but 1 s is the minimum value.






1 � 3 � 11


UL TBF Establishment 1-Phase Access on PCCCH, Success

MS BTS BSC MFS

TA calculationPRACH (4 A.B.)

(EGPRS)

Packet Channel request

MS switches

on assigned

PDCHs

Packet UL assignment

PAGCH


PDCHs, USFs, TFI, TAI, TA, CS (MCS, EGPRS window

size)


RLC data block

T_ACK_WAIT

PDTCH

RLC data block

Contention

resolution

TLLI, TFI

PACCH

Packet UL Ack/Nack

TLLI, TFI

Packet UL Ack/Nack

(EGPRS)


(TA)

(EGPRS) Multislot class

P30a P30d

GPRS EGPRS

P62a P62d

GPRS EGPRS

GCH allocation

(EGPRS)


(TA)

Possible causes for the one phase access for GPRS:

� 1-phase access (MS multislot class provided)

� Short access (less than 8 RLC blocks)

� Paging response

� Cell update

� MM procedures (GPRS Attach, GPRS Detach, RA update)

� Single block without TBF establishment

Note: The access indicating “Single Block Without TBF Establishment” is supported by the Alcatel BSS: such

an access is used by the MS to report a Packet Measurement Report message or a Packet Cell Change Failure

message in Packet Idle Mode

Possible causes for the one phase access for EGPRS:

� 1-phase access

� Short access

� Signaling

A EGPRS mobile provides both its GPRS multislot class and its EGPRS multislotclass. If the TBF can not be

established in EGPRS mode it will then be established in GPRS mode if possible. In this case the EGPRS

multislot class is used by the BSS to allocate the corresponding number of PDCHs. If the GPRS multislot class

is higher than the EGPRS one then the TBF is a candidate for a subsequent radio resource re-allocation to

extend the number of PDCHs.






1 � 3 � 12


UL TBF Establishment 2-Phases Access on PCCCH, Success

MS BTS BSC MFS

TA calculation

MS switches

on assigned

PDCHs

PACCHPacket resource request


PACCHPacket UL assignment

TLLI, PDCHs, USFs, TFI, TAI, TA, CS



Packet resource requestTLLI, MS Radio Access Capability, QoS

(Additional Radio Access Capability)

T_ACK_WAIT

Contention

resolution

RLC data block

PDTCH

RLC data block

MS switches

on allocated

RLC block(s)

PRACH (4 A.B.)

(EGPRS)



PAGCH


T_UL_Assign_PCCCH

PDCH id, TBF starting time, TA, 1

(multiple) block(s)


T3168

P62a P62d

GPRS EGPRS

P30a P30d

GPRS EGPRS

PDCH & GCH

allocation

(EGPRS)


(TA)

(EGPRS)


(TA)

Timer

T_UL_ASSIGN_PCCCH controls the duration between (EGPRS) Packet Request message and the UL radio

block allocated to the MS.

T_UL_ASSIGN_PCCCH = 0.4 s (default value). It can be set at the OMC-R level.

2-phase access is used when the MS wants specific QoS attribute values to be taken into account (e.g., RLC

Nack mode).






1 � 3 � 13


UL TBF Establishment during a DL TBF, Success

MS BTS BSC MFS

P30b

T_ACK_WAIT

DL transfer

RLC data block, pollingRLC data block

PDTCH

Packet DL Ack/Nack

PACCH(EGPRS) Packet DL Ack/Nack with Channel request


PACCH


PDCHs, USFs, TFIUL,TAI, CS (MCS, EGPRS window size)

P62b

T3168

PDTCH

USF Scheduling USF Scheduling

RLC data block

PDTCH

RLC data block

GPRS EGPRS

GPRS EGPRS

GCH allocation

This scenario corresponds to a UL TBF establishment in PTM without re-allocation of the on-going DL TBF.

The Packet UL Assignment message is repeated N_SIG_REPEAT times because if the MS has not decoded the

Packet UL Assignment then the MS tries again to establish the UL TBF only after T3168 expiry.

N_SIG_REPEAT = 1 (default value). It cannot be set at the OMC-R level. Therefore the Packet UL Assignment

is sent 2 times in a row.






1 � 3 � 14


UL TBF Establishment, Exercise

� Exercise 1: Identify the type of UL TBF establishment procedure among the provided traces 1, 2, 3, 9

� Exercise 2: Using the trace 2 , find how many TBFs are established and when?

� Exercise 3: Using the trace 2, identify the values of:

� TFIUL� TFIDL� PDCHs allocated for the UL TBF

Time allowed:

30 minutes






1 � 3 � 15

UL TBF Establishment Success Rate

TBF Establishment Efficiency TBF Establishment Preparation Success

TBF EstablishmentFailure BSS

TBF EstablishmentFailure Gb

TBF EstablishmentFailure Radio

Radio Congestion

Abis Congestion

Ater Congestion

DSP Congestion

DSP in load/overload

CPU Congestion

Too many TBF

TBF Estab Congestion Rate

Radio Congestion Duration

GPU congestion


UL TBF Establishment, Failures

Note:

� GPU congestion means that the maximum capacity of at least one DSP on the GPU is reached in terms of

resources GCH and/or PDCH.

� A lack of Ater resources occurs when there is not enough Ater nibbles to serve the UL TBF request.

� A lack of Abis transmission resources occurs when there is not enough Abis nibbles to serve the UL TBF

request.

The GPU is split into two sub-units : the Packet Management Unit (PMU) and the Packet Traffic Unit (PTU).

The functions managed by the PMU are implemented on the PowerPC (CPU) processor

The functions managed by the PTU are implemented on 4 Digital Signalling Processors (DSP) for a GPU board






1 � 3 � 16


UL TBF Establishment, Failures, Congestion

� Radio Congestion

1. maximum number of MSs per slave PDCH in uplink is reached

2. no TAI or TFI left in the MFS

3. no PDCH are granted to MFS due to a CS congestion and max_pdch_high_load=0

� Abis Congestion

UL TBF establishment fails due to a lack of Abis resources

� Ater Congestion

UL TBF establishment fails due to a lack of Ater resources

� Too Many TBF's

UL TBF establishment fails due to a too low number of available GCH, compared to the number of TBF's.

� DSP Congestion

maximum capacity of at least one DSP on the GPU is reached in terms of resources GCH and/or PDCH.

� DSP in load/overload state

UL TBF establishment fails due to the

internal cause CPU_DSP_LOAD

� CPU Congestion

UL TBF cannot be established due to CPU processing power limitations of the GPU

This slide is also valid for the description of the different causes of congestion during a DL TBF

establishment.






1 � 3 � 17


UL TBF Establishment, Failures, Congestion [cont.]

MS BTS BSC MFS

RACH

(EGPRS Packet)

Channel request

AGCH

Immediate assignment rejectImm. assign. command

(Imm. assign. Reject) Wait indication

No resource available (radio+Abis+Ater+Too

many TBF+DSP+ GPU+GPU-CPU)

P27+P105j+P105h+P105l+P204+P105d+P105f(EGPRS)

Packet Channel

request

PACCH

Packet access reject Packet access reject

Wait indication

or Packet resource request

or Packet DL Ack/Nack with

Channel request



Channel request

Channel request (TA)Channel required

(TA)

(EGPRS)


(TA)



Channel request

(EGPRS)


(TA)

Channel assignment UL

(Imm. assign. Reject)

Packet access reject

No resource available (radio+Abis+Ater+Too

many TBF+DSP+

GPU+GPU-CPU)

The first scenario corresponds to:

� the impossibility to allocate the resources for a UL TBF establishment 1-phase access on CCCH.

� the impossibility to allocate the UL block(s) for a UL TBF establishment 2-phase access on CCCH.

The second scenario corresponds to:

� the impossibility to allocate the resources for a UL TBF establishment 2-phase access on CCCH.

� the impossibility to allocate the resources for a UL TBF establishment during a DL TBF.






1 � 3 � 18


UL TBF Establishment on CCCH, Failures, Radio

MS BTS BSC MFS

RACHChannel request + TA

(EGPRS Packet)

Channel request

AGCH

Immediate assignment PDCH, TFI, USF, TAI, TA, CS


USF Scheduling

PDTCH

USF Scheduling

RLC data block

PDTCHT_GPRS_ASSIGN_AGCH

expiryP28


PACCH


TLLI, PDCHs, USFs, TFI, TAI, TA,

CS

(MCS, EGPRS window size)PDTCH

USF Scheduling

USF SchedulingT_ACK_WAIT

expiry

P28

Channel required

(TA)Channel assignment UL (IA)

Imm. assign. command

The first scenario corresponds to a radio failure occurring during a UL TBF establishment 1-phase access on

CCCH.

The second scenario corresponds to a radio failure occurring during a UL TBF establishment 2-phase access

on CCCH.

If the contention resolution fails, the MS will try to establish the UL TBF up to 4 times.

The radio problems counted are usually due to interference or bad coverage but Abis microwave

transmission problems or some BSS problems (RSL overload) can be counted as radio problems.






1 � 3 � 19


UL TBF Establishment on PCCCH, Failures, Radio

MS BTS BSC MFS

PRACH (4 A.B.)

(EGPRS)


Packet UL assignmentPAGCH

Packet UL assignmentPDCHs, USFs, TFI, TAI, TA, CS (MCS, EGPRS window size)


P28T_ACK_WAIT expiry


PDTCH

RLC data block

Packet UL assignmentPACCH

Packet UL assignmentTLLI, PDCHs, USFs, TFI, TAI, TA, CS



P28T_ACK_WAIT expiry

(EGPRS)


(EGPRS)


(TA)

The first scenario corresponds to a radio failure occurring during a UL TBF establishment 1-phase access on

PCCCH.

The second scenario corresponds to a radio failure occurring during a UL TBF establishment 2-phase access

on PCCCH.








1 � 3 � 20


UL TBF Establishment during a DL TBF, Failures, Radio

MS BTS BSC MFS

P28

DL transfer / Active or Delayed phase

RLC data block, pollingRLC data block

PDTCH

Packet DL Ack/Nack

PACCH(EGPRS) Packet DL Ack/Nack with Channel request


PACCH

Packet UL Assignment

PDCHs, USFs, TFIUL,TAI, CS (MCS, EGPRS window size)

T3168

PDTCH


T_ACK_WAIT expiry

If a DL TBF re-allocation is triggered upon a UL TBF establishment and if the DL TBF re-allocation fails due

to a radio problem then counter P28 is also incremented.








1 � 3 � 21

� Problem at Gb interface level

� When the CELL is in the operational state “disabled” in the BSS

� O&M problem

� Problem at BSS level

� which is not linked to Congestion, Radio, Gb

� no specific counter


UL TBF Establishment, Failures, Gb, BSS

MS MFS SGSN

<< UL establishment request >>

Cell identity

Cell BVC unavailable

P66

A problem at BSS level can be linked to a Hardware or a Software failure.






1 � 3 � 22


DL TBF Establishment on CCCH, MS in Ready State

MS BTS BSC MFS LLC PDU

PDCH, TFI, TAI, (EGPRS)Immediate assignment

PCH/AGCH (DRX/Non-DRX)

Packet DL assignment, polling

PDCHs, TFI, TAI, (EGPRS window size)PACCH

Packet DL assignment

PACCH (4 A.B.)

Packet control AckPacket control AckTA calculation

Timing Advance / Power control

PACCH

TA / PC

PDTCH

RLC data block

MS

switches

on

assigned

PDCH

P91f, P91c

T3190

t_assign_agch_paccht_assign_pch_pacch

expiry & restart

P90f, P90c

P91g

GPRS

EGPRS

P90g

GPRS

EGPRS

P53c, P49

GCH allocation

Channel assignment DL (IA)Imm. assign. command

If the MFS does not receive the Packet Control Ack message from the MS:� it sends again the Packet Downlink Assignment message up to MAX_GPRS_ASSIGN_PCH_RETRANS if the MS is

in DRX mode or up to MAX_GPRS_ASSIGN_AGCH_RETRANS if the MS is in Non-DRX mode.� if the Maximum number of retransmission of Packet Downlink Assignment message is reached then the MFS

restarts the whole DL TBF establishment procedure up to MAX_DL_RETRANS times.� MAX_GPRS_ASSIGN_PCH_RETRANS = 3 (default value)� MAX_GPRS_ASSIGN_AGCH_RETRANS = 3 (default value)� MAX_DL_RETRANS = 3 (default value)

� The other establishment attempts of the same TBF are not counted, only the first attempt is counted.

Timers� T_GPRS_ASSIGN_AGCH: controls the reception of the Packet Control Ack message from the MS in Non-DRX

mode.� T_GPRS_ASSIGN_AGCH = 0.8 s (default value) but computed as a function of the CCCH configuration

in the cell. It cannot be set at the OMC-R level.� T_GPRS_ASSIGN_AGCH" is the HMI name of "T_ul_assign_ccch" described in the BSS telecom

parameters catalogue.� T_GPRS_ASSIGN_PCH: controls the reception of the Packet Control Ack message from MS in DRX mode.

� T_GPRS_ASSIGN_PCH = 1.4 s (default value) but computed as a function of the BS_PA_MFRMS CCCH parameter in the cell. It cannot be set at the OMC-R level.

� T_GPRS_ASSIGN_PCH" is the HMI name of "T_dl_assign_ccch" described in the BSS telecom parameters catalogue.

� t_assign_agch_pacch: is the time the MFS waits for the Packet Control Ack message after having sent the Packet Downlink Assignment message to the MS in Non-DRX mode before repeating the Packet Downlink Assignment message.

� Its value is computed as T_GPRS_ASSIGN_AGCH / (MAX_GPRS_ASSIGN_AGCH_RETRANS + 1).� t_assign_pch_pacch: is the time the MFS waits for the Packet Control Ack message after having sent the

Packet Downlink Assignment message to the MS in DRX mode before repeating the Packet Downlink Assignment message.

� Its value is computed as T_GPRS_ASSIGN_PCH / (MAX_GPRS_ASSIGN_PCH_RETRANS + 1).� T3190: if this timer expires, the MS returns into Packet Idle Mode.

� T3190 = 5s (default value).






1 � 3 � 23


DL TBF Establishment on PCCCH, MS in Ready State

MS BTS BSC MFS LLC PDU

PPCH

(first/paging group)


PDCHs, TFI, TAI, (EGPRS window size)


PACCH (4 A.B.)

Packet control AckPacket control AckTA calculation

Timing Advance / Power control

PACCH

TA / PC

PDTCH

RLC data block

T3190

P90d, P90a

MS

switches

on

assigned

PDCH

T_ACK_WAIT

T_ACK_WAIT_DRX_PCCCH

P91g

GPRS

EGPRS

P91d, P91a

P90g

GPRS

EGPRS

GCH allocation

If the MFS does not receive the Packet Control Ack message from the MS:

� the MFS restarts the whole DL TBF establishment procedure up to MAX_DL_RETRANS times.

� MAX_DL_RETRANS = 3 (default value)


Timers

� T_ACK_WAIT: controls the reception of the Packet Control Ack message from the MS in Non-DRX mode.

� T_ACK_WAIT = 1.2 s (default value). It cannot be set at the OMC-R level.

� T_ACK_WAIT_DRX_PCCCH: controls the reception of the Packet Control Ack message from the MS in DRX

mode.

� T_ACK_WAIT_DRX_PCCCH = 2.5 s (default value). It cannot be set at the OMC-R level.

� T3190: if this timer expires, the MS returns into Packet Idle Mode.

� T3190 = 5 s (default value)






1 � 3 � 24

T3190


DL TBF Establishment during a UL TBF

MS BTS BSC MFS

UL transfer


PACCH

Packet DL assignment, po

lling

PDCH(s), TFIDL, TAI, (EGPR

S window

size)

P91b

P90b

T_ACK_WAITPacket control AckPacket control Ack

RRBP

LLC PDU

PDTCHRLC data blo

ck

RRBP+

40 ms

GCH allocation

This scenario corresponds to a DL TBF establishment in PTM without re-allocation of the on-going UL TBF.






1 � 3 � 25

semantic

0

1

The SDU contains signaling (e.g., related to GMM)

The SDU contains data

coding

“T bit” coding


DL TBF Establishment, Radio Resource Optimization

MFS

BSSGP PDUn PDCHs

allocated

according to

MS multislot

class

SGSN

(QoS profile, LLC PDU)

Only 1 PDCH allocated

n PDCHs allocated

according toMS multislot class

8

octet 1

octet 2.2a

octet 3-4

octet 5

IEI

Length Indicator

Peak bit rate provided by the network, coded as the value part in Bucket Leak Rate/R IE/ GSM 08.18 a)

7 6 5 4 3 2 1

SPARE C/R T A Precedence

QoS Profile IE from BSSGP message GSM 08.18






1 � 3 � 26


DL TBF Establishment, Exercise

� Exercise 1: Identify the type of DL TBF establishment procedure among the provided traces 6, 6bis, 8 and 9

� Exercise 2: identify trace 6bis if the DL TBF is established for data or signaling transfer

Time allowed:

30 minutes






1 � 3 � 27


DL TBF establishment, Failures

DL TBF Establishment Success Rate

TBF Establishment Efficiency TBF Establishment Preparation Success

TBF EstablishmentFailure BSS

TBF EstablishmentFailure Gb

TBF EstablishmentFailure Radio

Radio Congestion

Abis Congestion

Ater Congestion

DSP Congestion

DSP in load/overload

CPU Congestion

Too many TBF

TBF Estab Congestion Rate

Radio Congestion Duration

GPU congestion






1 � 3 � 28

� BSS resource congestion: radio (PDCH, TAI, TFI), Ater, GPU

� Problem at Gb interface level

� When the CELL is in the operational state “disabled” in the BSS

� O&M problem


DL TBF Establishment, Failures, Cong and Gb

MFS

LLC PDUsNo resource available: (radio+Abis+Ater+DSP+CPU)+ CPU_LOAD + too many TBFs

P14+ P105i+ P105g+P105c+P105e+P203+

P105k

SGSN

LLC Discarded

MFS

LLC PDUs

Cell BVC unavailable

P65

SGSN

LLC Discarded






1 � 3 � 29

� Radio problem


� what is not Congestion, Radio, Gb…



DL TBF Establishment, Failures, Radio

MSBTS BSC MFS

Packet control Ack

t_assign_agch_pacch expiry

or t_assign_pch_pacch expiry

or T_ACK_WAIT expiry

for the last attempt of the same DL TBF establishment


PDCHs, TFI, TAI, (EGPRS window size)


PACCH or PPCH

PACCH

P15

If a UL TBF re-allocation is triggered upon a DL TBF establishment and if the UL TBF re-allocation fails due

to a radio problem then counter P15 is also incremented.








1 � 3 � 30


Fast DL TBF Re-establishment, Success

T3192

MS BTS BSC MFS

DL transfer


PACCH

Packet DL assignment, po

lling

PDCH(s), TFIDL, TAI, (EGPR

S window

size)

P91e

P90e

T_ACK_WAITPacket control AckPacket control Ack

RRBP

LLC PDUSame resources

allocation

PDTCHRLC data blo

ck

RRBP+

40 ms

end

begin

T3192&

T3192n

T3190

If the MFS does not receive the Packet Control Ack message from the MS:

� the MFS restarts the whole DL TBF establishment procedure up to MAX_DL_RETRANS times.

� MAX_DL_RETRANS = 3 (default value)


Timers

� T_ACK_WAIT: controls the reception of the Packet Control Ack message from the MS in Non-DRX mode.

� T_ACK_WAIT = 1.2 s (default value). It cannot be set at the OMC-R level.

� T3190: if this timer expires, the MS returns into Packet Idle Mode.

� T3190 = 5 s (default value)






1 � 3 � 31


Fast DL TBF Re-establishment, Failures

� All types of failures are counted in the same counters as for other kinds of DL TBF establishment

� BSS resource congestion

� radio (PDCH, TAI, TFI): P14

� Abis: P105i

� Ater: P105g

� GPU DSP Congestion: P105c

� GPU CPU processing power limitations: P105e

� DSP Load/Overload: P203

� Too many TBFs: P105k

� radio: P15

� Gb: P65

� BSS: no specific counter






1 � 3 � 32


PS Paging

MS BTS BSC MFSSGSN

LLC PDU

MS inStandby

PS Paging

PCH/PPCH

Paging Request/Packet Paging Request

RACH/PRACH

Channel Request/Packet Channel Request

cause =?/cause =?

AGCH/PAGCH

Immediate Assignment/Packet Uplink Assignment

MS Ready

DL UNITDATA PDU

USF Scheduling

PDTCH

PDTCH

Sending of an LLC PDU (RLC blocks)

containing GMM Paging response message

Procedure 1 ?

Procedure 2 ?

P53a/P61a

P53b/P61b

P391a

P391b

PS

PS

CSCS

� Identify the procedures 1 and 2 on the following diagram

A CS Paging Request can be sent by the SGSN to the MS through the GMM PS Paging message if the GS

interface exists (GPRS network configured in NMO I).

In the case a CS Paging Request sent on PCH or PPCH the MS performs a CS Radio Link Establishment

procedure.






1 � 3 � 33


PS Paging, Exercise

� Exercise: Using the trace 7, find the cell in which the MS is located

Time allowed:

30 minutes






1 � 3 � 34


Reduction of the Ping Duration B10

MS BTS BSC MFS

DL transfer (delayed state)

Packet DL Ack/Nack (EGPRS) Packet DL Ack/Nack with Channel request

Packet UL assignmentPacket UL assignment


RLC data block RLC data block

SGSN


LCC (Echo Req)

LCC (Echo Rep)RLC data block RLC data block


Key Improvements, compared to B9:

PDAN to PUAS delay reduction

DL LLC PDU to DL RLC block delay reduction

Last DL RLC block sent in the same radio block as the other blocks

Improvement for EDGE mobiles, with BSC/MFS Evolution

Duration of Ping 32 bytes 0 second:

B9: 255~247ms

B10: 208~197ms






1 � 3 � 35


PS Paging, Exercise (Reduction of Ping Time)

� Exercise: In the following trace measure the PING duration

� Trace 18

� Can you find the same case as in the previous slide?

� In which state is the UL TBF before the ping?

� Exercise 2: Identify the length of the echo request message

Time allowed:

30 minutes

B10






1 � 3 � 36


TBF Establishments: Dual Transfer Mode

MS in dedicated mode

UL TBF establishment DL TBF establishment

TCH change Same TCH TCH change Same TCH

MS in MM Ready state MS in MM Standby stateMS in MM Ready state

PS Paging

B10

MS in Dual Transfer Mode






1 � 3 � 37


UL TBF Establishment in Dedicated Mode B10

DTM Request (2)[main DCCH]

Packet Assignment (5)

BSC Shared DTM Info Indication

BSCGP DTM Request (3)

Assignment Complete (6)

[FACCH]

UL radio blocks (7)

UL LLC PDUs[PDCH]

USF … USF … USF

T3148n (BSC)T3148n (MFS)

T_ACK_WAIT

MS BTS BSC MFS

P507

P508

MC927c

T3148 (IMSI, PUAS)

(TFI, TAI, USFs, PDCHs)

(TLLI, QoS, cause)(IMSI, current TCH)

BSCGP DTM Assign CMD (4)

Dedicated mode (TCH) (1)

1. It is assumed that the MFS has been informed that the MS is in dedicated mode.

2. The MS requests the establishment of a PS session by sending a DTM Request message and starts timer T3148. This message contains:

� TLLI of the MS� Radio priority (four possible values)� RLC mode associated with the packet transfer (RLC acknowledged mode or RLC unacknowledged

mode)� LLC frame type (whether or not the first LLC PDU is SACK or ACK)� Establishment cause (User data, Page response, Cell update, or MM procedure)� Peak Throughput Class and RLC_OCTET_COUNT field (indicating the number of RLC data volume

to be transferred)� Optionally the PFI

3. The BSC forwards the request to the MFS through a new message called BSCGP DTM Request. This message contains the references of the MS (i.e., IMSI and BSC reference) and the identity of the radio timeslot currently allocated to the MS. The radio timeslot identity is used to know whether or not the TCH needs to be re-assigned.

4. The MFS sends to the BSC a new message called BSCGP DTM Assignment Command. This message contains the references of the MS (i.e., IMSI), and the RR Packet Uplink Assignment IE that will be transparently sent in the 44.018 Packet Assignment message. This IE provides the MS with information required for the UL TBF allocation (TFI, TAI, USF and PDCHs). USF(s) are scheduled as soon as the BSCGP DTM Packet Assignment message is sent and the timer T_ACK_WAIT is started to monitor the beginning of the UL TBF.

5. The BSC builds the Packet Assignment message based on the information retrieved from the MFS and sends it to the MS on the main DCCH. The BSC starts timer T3107 to monitor the receipt of the Assignment Complete message. On receipt of the 44.018 Packet Assignment message, the MS stops timer T3148.

6. On receipt of the Assignment Complete message, the BSC stops timer T3107 and sends a BSC Shared DTM Info Indication message to the MFS, indicating the successful end of the DTM assignment procedure.

7. The MS starts sending UL RLC blocks on the new assigned PDCH(s).






1 � 3 � 38


UL TBF Establishment in Dedicated Mode – TCH Change B10

DTM Request (2)[old main DCCH]

Chan. Act. (new TCH)

Chan. Act. ACK

DTM Assignment Command (5)


BSCGP DTM Request (3)


Assignment Complete (6)[new FACCH]

UL radio blocks (7)

UL LLC PDUs[PDCH]

USF … USF … USF


T_ACK_WAIT

MS BTS BSC MFS

P507

P508

MC927a

T3148 (IMSI, TCH, PUAS)

(TCH, TFI, TAI, USFs, PDCHs)


T3107


1. It is assumed that the MFS has been informed that the MS is in dedicated mode.

2. The MS requests the establishment of a PS session by sending a DTM Request message and starts timer T3148. This message contains:

� TLLI of the MS� Radio priority (four possible values)� RLC mode associated with the packet transfer (RLC acknowledged mode or RLC unacknowledged

mode)� LLC frame type (whether or not the first LLC PDU is SACK or ACK)� Establishment cause (User data, Page response, Cell update, or MM procedure)� Peak Throughput Class and RLC_OCTET_COUNT field (indicating the number of RLC data volume

to be transferred)� Optionally the PFI

3. The BSC forwards the request to the MFS through a new message called BSCGP DTM Request. This message contains the references of the MS (i.e., IMSI and BSC reference) and the identity of the radio timeslot currently allocated to the MS. The radio timeslot identity is used to know whether or not the TCH needs to be re-assigned.

4. The MFS sends to the BSC a new message called BSCGP DTM Assignment Command. This message contains the reference of the MS (i.e. IMSI), the new TCH to be assigned to the MS, and the RR Packet Uplink Assignment IE that will be transparently sent in the 44.018 DTM Assignment Command message. This IE provides the MS with information required for the UL TBF allocation (TFI, TAI, USF and PDCHs). USF(s) are scheduled as soon as the BSCGP DTM Assignment Command is sent and the timer T_ACK_WAIT is started to monitor the beginning of the UL TBF.

5. The BSC activates the new TCH, builds the DTM Assignment Command message based on the information retrieved from the MFS and sends it to the MS on the old main DCCH. The BSC starts timer T3107 to monitor the receipt of the Assignment Complete message. On receipt of the 44.018 DTM Assignment Command message, the MS stops timer T3148.

6. On receipt of the Assignment Complete message, the BSC stops timer T3107 and sends a BSC Shared DTM Info Indication message to the MFS, indicating the successful end of the DTM assignment procedure.

7. The MS starts sending UL RLC blocks on the new assigned PDCH(s).






1 � 3 � 39


UL TBF Establishment in Dedicated Mode, Failures

� DTM


� what is not Congestion, Radio


DTM UL TBF

establishment FAILURE

Radio Resource Congestion

Radio failure BSS pb

B10






1 � 3 � 40


UL TBF Establishment in Dedicated Mode, Failure, Cong B10

DTM Request[main DCCH]BSCGP DTM Request

expiry


MS BTS BSC MFS

P507

T3148


BSCGP DTM Reject

Dedicated mode (TCH)

P512

P507: Number of UL TBF establishment requests on DCCH for MS operating in DTM.

P512: Number of UL TBF establishment failures on DCCH for MS operating in DTM due to a lack of radio resources.






1 � 3 � 41


UL TBF Establishment in Dedicated Mode, Failure, Radio B10

DTM Request[main DCCH]

Packet Assignment

BSCGP DTM Request

[FACCH]

USF … USF … USF


T_ACK_WAIT

MS BTS BSC MFS

P507

MC927c

T3148 (IMSI, PUAS)

(TFI, TAI, USFs, PDCHs)


BSCGP DTM Assign CMD


expiry

P28

UL RLC Block


P28: Number of UL TBF establishment failures at the expiry of T_ACK_WAIT timer (typical UL TBF Establishment Failure due to Radio problems, not specific to DTM)






1 � 3 � 42


UL TBF Establishment in Dedicated Mode, Failure, Radio B10

DTM Request[main DCCH]BSCGP DTM Request

Data Indication

(DTM Assign Failure)

[FACCH]

USF … USF … USF


MS BTS BSC MFS

P507

MC927c

T3148 (IMSI,TCH, PUAS)


BSCGP DTM Assign CMD


expiry

P28

� With TCH change

BSCGP DTM Assign Failure

T3107


(TCH, TFI, TAI, USFs, PDCHs)

DTM Assign Failure

Establish Indication

MC927e

T_ACK_WAIT

stop

or


P28: Number of UL TBF establishment failures at the expiry of T_ACK_WAIT timer.

MC927e: Number of UL TBF establishment in DTM with reallocation of the TCH with execution failures due to MS access problem.






1 � 3 � 43


DL TBF Establishment in Dedicated Mode B10

Packet Assignment (4)


[FACCH]

DL radio blocks (5)

DL LLC PDUs (2)

[PDCH]

T_DTM_ASSIGN

MS BTS BSC MFS


P505

P506

MC927d

(IMSI, PDAS)

(TFI, TAI, PDCHs)

(IMSI)

T_ACK_WAIT

PDAN

expiry

BSCGP BSCShared DTM Info Indication

(IMSI's of all DTM MS'sin dedicated mode)

BSCGP BSCShared DTM Info Indication

8s.

Note: the "Shared DTM Info Indication" is sent periodically to the MFS (every T_SHARED_DTM_INFO = 8s), to

ensure the PS paging co-ordination for DTM MS in dedicated mode.

1. While the MS is in GMM ready state, the MFS receives a DL LLC PDU including the IMSI of the MS.

2. It is assumed here that the identity of the TCH used by the MS is known by the MFS (i.e. there is a TCH assigned to the MS). The MFS first checks whether the TCH needs to be re-assigned. It prepares accordingly the radio (TCH and PDCH) and transmission (PDCH only) resources required to serve the DL request.The MFS sends to the BSC the new BSCGP DTM Assignment Command message. This message contains the references of the MS (i.e. IMSI and BSC reference) and the contents of the 44.018 Packet Assignment message. This IE provides the MS with information required for the DL TBF establishment (DL TFI, TAI, and PDCHs). The MFS also starts T_DTM_ASSIGN.

3. The BSC sends to the MS the 44.018 Packet Assignment message on the main DCCH.

4. At T_DTM_ASSIGN expiry, the MFS starts sending DL RLC data blocks and starts T_ACK_WAIT to monitor DL TBF establishment (at the first occurrence of PACCH, the MFS polls the MS). Note that the MFS does not need to provide the MS with the GPRS timing advance since this value is ignored by the MS when the MS is in dual transfer mode. T_ACK_WAIT will be stopped at reception of the first PDAN.






1 � 3 � 44


DL TBF Establishment in Dedicated Mode – TCH Change B10

Chan. Act. (new TCH)

Chan. Act. ACK




Assignment Complete (5)

[old FACCH]

DL radio blocks (6)

DL LLC PDUs (2)

[PDCH]

T_DTM_ASSIGN

MS BTS BSC MFS


P505

P506

MC927b

(IMSI, TCH, PDAS)

(TCH, TFI, TAI, PDCHs)T3107

(IMSI)

T_ACK_WAIT

[new FACCH]

PDAN

expiry

1. The MS is in dedicated mode and in GMM ready state.

2. While the MS is in GMM ready state, the MFS receives a DL LLC PDU including the IMSI of the MS.

3. It is assumed here that the identity of the TCH used by the MS is known by the MFS (i.e. there is a TCH assigned to the MS). The MFS first checks whether the TCH needs to be re-assigned. It prepares accordingly the radio (TCH and PDCH) and transmission (PDCH only) resources required to serve the DL request.The MFS sends to the BSC the new BSCGP DTM Assignment Command message. This message contains the references of the MS (i.e. IMSI and BSC reference), the identify of the new TCH, and the RR Packet Downlink Assignment IE that will be transparently sent in the 44.018 DTM Assignment Command message. This IE provides the MS with information required for the DL TBF establishment (DL TFI, TAI, and PDCHs).The MFS also starts T_DTM_ASSIGN.

4. The BSC activates the new TCH, builds the DTM Assignment Command message based in the information retrieved from the MFS and sends it on the old main DCCH. The BSC starts timer T3107 to monitor the receipt of the Assignment Complete message.

5. On receipt of the Assignment Complete message, the BSC stops timer T3107, releases the old TCH and sends a BSC Shared DTM Info Indication message to the MFS, indicating the successful end of the DTM assignment procedure.

6. At T_DTM_ASSIGN expiry, the MFS starts sending DL RLC data blocks and starts T_ACK_WAIT to monitor DL TBF establishment (at the first occurrence of PACCH, the MFS polls the MS). Note that the MFS does not need to provide the MS with the GPRS timing advance since this value is ignored by the MS when the MS is in dual transfer mode.T_ACK_WAIT will be stopped at reception of the first PDAN.






1 � 3 � 45


DL TBF Establishment in Dedicated Mode, Failures

� DTM


� what is not Congestion, Radio


DL TBF establishment FAILURE

Radio Resource Congestion

Radio pb BSS pb

B10

P511 MC927f






1 � 3 � 46


PS Paging in Dedicated Mode B10

Packet Notification (4)

BSCGP DTM Packet Notification (3)

[FACCH]

PS paging (2)

MS BTS BSC MFS


(CI, IMSI)

(IMSI)

BSCGP DTM Packet Notification ACK (4)

UL LLC PDUs

Packet Paging Response (5)

T_WAIT_DTM

1. The MS is in dedicated mode and in GMM standby state.

2. As the MS is in GMM Standby state, if the SGSN has something to send to the MS, the SGSN shall first page the MS in the routing area where the MS is located.

3. Upon receipt of the PS paging, the MFS first checks whether the concerned MS is in dedicated mode (based on information provided by the BSC). If this is the case, the MFS sends to the BSC a BSCGP DTM Packet Notification message providing the BSC with the cell identity, the references of the MS (i.e. IMSI and BSC reference) and the contents of the 44.018 Packet Notification message.

4. Then, the BSC forwards the 44.018 Packet Notification message to the MS on the main DCCH and sends a BSCGP DTM Packet Notification ACK to the MFS for acknowledgement.

5. On receipt of the Packet Notification message, the MS shall answer to the notification with a cell update procedure, i.e. by sending an LLC frame acting as a Packet Paging Response. Two cases can then occur:

� If the UL LLC frame does not convey user data information and is short enough (according to the value of the MAX_LAPDM parameter), the MS uses the GTTP to send the dummy UL LLC frame to the SGSN.

� Otherwise, the MS requests the establishment of an UL TBF with a 44.018 DTM Request message and sends the UL LLC PDU on the established UL TBF.






1 � 3 � 47

� DL and UL TBF establishment:

TBF establishment

startNumber of requestsNumber of successes

Success rate

Failure causes

time

TBF establishment

end

Congestion

Radio

BSS

Gb

Distribution of number of TSs requested / obtained

Radio

Abis

Ater

Different cases:

• DL/UL: idle & transfer mode

• DL/UL: MPDCH or not

• DL: DRX & non-DRX

• DL: T3192 running

•DL/UL: MS EGPRS capableAllocation rate


QoS Indicators

DSP

CPU

The number of TBF establishment requests gives an idea of the GPRS traffic. It is therefore a KPI.

Nb of Allocation successes = Nb of Requests - Nb of Congestions

A radio pb can be specific to GPRS (no radio pb for GSM): it can be due to the MS behavior (bad handling of

Polling from the BSS).

Some tests on Ping have shown that RTT (Round Trip Time) is varying from one MS to another. Some MSs are

considered to be slow, others to be fast. Round Trip Time is the time duration of data transmission from

mobile to data server then back from server to mobile. Usually RTT is assessed using a PING command of 32

bytes data transmission. If the data server is connected to the Gi interface RTT will be a measurement of

twice the time duration needed to send data across the GPRS network.






1 � 3 � 48

� DL and UL TBF establishment: requests/successes

Transfer phase Fast DL TBF re-establishment T3192 Non-DRX mode DRX mode

time

GPRS/EGPRSrequest/success

GPRS/EGPRSrequest/success

OnlyEGPRS

OnlyEGPRS


QoS Indicators, Request/Success

DL TBF establishment requests DL TBF establishment successes Transfer mode P91b Transfer mode P90b While T3192 running P91e While T3192 running P90e Idle mode + non-DRX mode + MPDCH P91d Idle mode + non-DRX mode + MPDCH P90d Idle mode + non-DRX mode + no MPDCH P91f Idle mode + non-DRX mode + no MPDCH P90f Idle mode + DRX mode + MPDCH P91a Idle mode + DRX mode + MPDCH P90a Idle mode + DRX mode + no MPDCH P91c Idle mode + DRX mode + no MPDCH P90c Idle mode + with / without MPDCH P91g Idle mode + with / without MPDCH P90g

UL TBF establishment requests UL TBF establishment successesIdle mode + MPDCH P62a Idle mode + MPDCH P30aIdle mode + no MPDCH P62c Idle mode + no MPDCH P30cTransfer mode P62b –

P438cTransfer mode P30b

Idle mode + with / without MPDCH P62d Idle mode + with / without MPDCH P30d

All other counters have been modified in order to take into account the TBFs established in EGPRS mode.






1 � 3 � 49

� DL and UL TBF establishment: failures

% TBF establishment failures Downlink Uplink

Congestion rate (radio-Abis- Ater-GPU)

(P14 + P105g + P105c + P105e+P105i) / (P91a +P91b+ P91c + P91d + P91e + P91f)

Congestion (radio-Abis-Ater-GPU) rate

(P27 + P105h + P105d + P105f+P105j) / (P62a + P62b + P62c)

Radio congestion rate P14 / (P91a + P91b + P91c + P91d + P91e + P91f) Radio congestion rate P27 / (P62a + P62b + P62c) % of time during which PDCH allocation for DL TBF is not possible due to congestion

(P13 / 10) / GP % of time during which PDCH allocation for UL TBF is not possible due to congestion

(P26 / 10) / GP

Abis congestion rate (P105i) / (P91a + P91b + P91c + P91d + P91e + P91f) Abis congestion rate (P105j) / (P62a + P62b + P62c - P438c) ATer congestion rate P105g / (P91a + P91b + P91c + P91d + P91e + P91f) ATer congestion rate P105h / (P62a + P62b + P62c) DSP congestion rate P105c / (P91a + P91b + P91c + P91d + P91e + P91f) DSP congestion rate P105d / (P62a + P62b + P62c) CPU congestion rate P105e / (P91a + P91b + P91c + P91d + P91e + P91f) CPU congestion rate P105f / (P62a + P62b + P62c) Radio problem rate P15 / (P91a + P91b + P91c + P91d + P91e + P91f) Radio problem rate P28 / (P62a + P62b + P62c) Gb problem rate P65 / (P91a + P91b + P91c + P91d + P91e + P91f) Gb problem rate P66 / (P62a + P62b + P62c) BSS problem rate (P91a + P91b + P91c + P91d + P91e + P91f - P14 -

P15 - P90a - P90b - P90c- P90d - P90e - P90f - P105e - P105c - P105g - P105i - P203) / (P91a + P91b + P91c + P91d + P91e + P91f)

BSS problem rate ((P62a + P62b + P62c - P438c - P27 - P28 - P30a - P30b - P30c - P66 - P105h - P105f - P105d - P105j - P204) / (P62a + P62b + P62c - P438c))


QoS Indicators, Failure

A CPU load state is managed per GPU. When the CPU load state reaches the maximum (crosses a high

threshold) then no new TBF can be established on this GPU.

Radio congestion is often low. When high, it is often linked to a GPU reset or to a problem at BSS level.

Therefore Indicators based on distribution of nb of TSs allocated/requested give a better idea of the

“congestion” situation.

On DL TBF establishment failure: a RADIO STATUS message is sent to the SGSN.






1 � 3 � 50

� DL and UL TBF establishment: success rate


QoS Indicators, KPI

((P62a + P62b + P62c - P438c + P507) - (P105d + P105f + P27 + P105h + P105j + P105l + P204 + P512)/ (P62a + P62b + P62c - P438c + P507))

((P91a + P91b + P91c + P91d + P91e + P91f + P505) - (P105c + P105e + P14 + P105g + P105i + P105k + P203 + P511)) / (P91a + P91b + P91c + P91d + P91e + P91f + P505)

TBF establishment allocated rate

(P30a + P30b + P30c + P508) / (P62a + P62b + P62c - P438c + P507)

(P90a + P90b + P90c + P90d + P90e + P90f + P506) / (P91a + P91b + P91c + P91d + P91e + P91f + P505)

TBF establishment success rate

P30a + P30b + P30c + P508P90a + P90b + P90c + P90d + P90e + P90f + P506

nb of TBF establishment successes

P62a + P62b + P62c - P438c + P507P91a + P91b + P91c + P91d + P91e + P91f + P505

nb of TBF establishment requests

uplinkdownlinkIndicator

TBF establishment requests and successes

KPI

KPI






1 � 3 � 51

� Thresholds:

� Significant traffic is reached for 2000 DL TBF requests/cell/day

(less when a Delayed downlink TBF release is activated)

� A UL/DL TBF establishment success rate is seen as good above 95%(except if CS2 is used at the beginning of a DL TBF)

Downlink TBF Establishment

02000400060008000

10000120001400016000

14/08

/2003

16/08

/2003

18/08

/2003

20/08

/2003

22/08

/2003

24/08

/2003

26/08

/2003

28/08

/2003

30/08

/2003

01/09

/2003

03/09

/2003

05/09

/2003

07/09

/2003

09/09

/2003

11/09

/2003

13/09

/2003

90

92

94

96

98

100

102 BSS fail

Gb fail

Radio fail

Congestion

Request

% Allocated

% Success


QoS Indicators, DL TBF Establishment, Graph

Typical values of DL establishment success rate when CS2 is used at the beginning of DL TBF: 94%, 96%.

TBF establishment indicators should be provided on a per DL and UL basis because the procedures are very

different and QoS has to be assessed and interpreted differently.

The UL TBF establishment can be degraded because of ghost Random Access messages.

The amount of bytes transferred at RLC or LLC level should be considered as a significant traffic indicator

(more Web browsing usage than WAP).

The nb of DL TBF establishment requests can should be considered as a GPRS activity indicator.






1 � 3 � 52

� DL and UL TBF establishment while MS is in dedicated mode:

TBF establishment

start

Number of requestsNumber of successes

Success rate

Failure causes

time

TBF establishment

end

Congestion

Radio

BSS

Radio

Allocation rate


QoS Indicators, DTM B10






1 � 3 � 53

� DL and UL TBF establishment while MS is in dedicated mode:


QoS Indicators, TBF Establishment in Dedicated Mode B10

P508Number of UL TBF establishment successes on DCCH for MS operating in DTM

NB_DTM_UL_TBF_EST_SUCC

MC927aNumber of UL TBF establishment attempts in DTM with reallocation of the TCH (sending of DTM Assignment Command with UL TBF)

NB_DTM_UL_TCH_ASS_ATPT

MC927aNumber of DL TBF establishment attempts in DTM with reallocation of the TCH (sending of DTM Assignment Command with DL TBF)

NB_DTM_DL_TCH_ASS_ATPT

MC927cNumber of UL TBF establishment attempts in DTM without reallocation of the TCH (sending of Packet Assignment Command with UL TBF)

NB_DTM_UL_PACKET_ASS_ATPT

MC927dNumber of DL TBF establishment attempts in DTM without reallocation of the TCH (sending of Packet Assignment Command with DL TBF)

NB_DTM_DL_PACKET_ASS_ATPT

P501Number of DTM contexts createdNB_DTM_MS_CONTEXT_CELL

P507Number of UL TBF establishment requests on DCCH for MS operating in DTM.

NB_DTM_UL_TBF_EST_REQ

P506Number of DL TBF establishment successes on DCCH for MS operating in DTM

NB_DTM_DL_TBF_EST_SUCC

P505Number of DL TBF establishment requests on DCCH for MS operating in DTM

NB_DTM_DL_TBF_EST_REQ

RefdefinitionIndicator name

P505:This counter is incremented when the MFS receives the first DL LLC PDU for a MS in dedicated mode (and in GMM ready state).

Note:

� This counter applies only to DTM capable mobiles.

� DL LLC PDU sent with BSCGP DTM GPRS information are not taken into account.

P927a: this counter is incremented whenever the BSC sends (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the "Description of the Uplink Packet Channel Assignment" optional IE

P927d: this counter is incremented whenever the BSC sends (through the BTS) 44.018 PACKET ASSIGNMENT message that includes the "Description of the Downlink Packet Channel Assignment" optional IE.

P506: This counter is incremented when the MFS receives the first Packet Downlink ack (following the reception of a DL LLC PDU for a MS in dedicated mode). This counter applies only to DTM capable mobiles.

P508: This counter is incremented when the MFS receives the first UL RLC data block for a MS in dedicated mode. This counter applies only to DTM capable mobiles.

P927a: This counter is incremented whenever the BSC sends (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the "Description of the Uplink Packet Channel Assignment" optional IE.

P927c: This counter is incremented whenever the BSC sends (through the BTS) 44.018 PACKET ASSIGNMENT message that includes the "Description of the Uplink Packet Channel Assignment" optional IE.

P509: This counter is incremented for DTM capable MS with ongoing DL TBF established, when an abnormal DL TBF release, occurs:

� When the DTM mode is leaved ( release of the CS connection in DTM mode).

� When in DTM mode an intercell or an intracell handover occurs.

� When in PTM the dedicated mode is entered.






1 � 3 � 54

� DL and UL TBF establishment failure while MS is in dedicated mode:


QoS Indicators, TBF Failure in Dedicated Mode B10

MC927eNumber of UL TBF establishment in DTM with reallocation of the TCH - execution failures due to MS access problem

NB_DTM_UL_TCH_ASS_EXEC_FAIL_RADIO

P512Number of UL TBF establishment failures on DCCH for MS operating in DTM due to a lack of radio resources

NB_DTM_UL_TBF_FAIL_CONG

MC927fNumber of DL TBF establishment in DTM with reallocation of the TCH - execution failures due to MS access problem

NB_DTM_DL_TCH_ASS_EXEC_FAIL_RADIO

P511Number of DL TBF establishment failures on DCCH for MS operating in DTM due to a lack of radio resources

NB_DTM_DL_TBF_FAIL_CONG


P511: This counter is incremented when MFS has no suitable radio resources to enter in DTM mode.

P927f: This counter is incremented:

� Whenever the BSC receives from the BTS a DATA INDICATION (DTM ASSIGNMENT FAILURE) message after

having sent (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the "Description of

the Downlink Packet Channel Assignment" optional IE.

� After having sent (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the

"Description of the Downlink Packet Channel Assignment" optional IE, upon T3107 expiry, the BSC does not

receive neither DTM ASSIGNMENT FAILURE (on the old channel) nor ASSIGNMENT COMPLETE (on the new

channel) messages.

P512: This counter is incremented when the MFS sends the BSCGP DTM reject message in case of lack of radio resources available.

P927e: This counter is incremented:

� Whenever the BSC receives from the BTS a DATA INDICATION (DTM ASSIGNMENT FAILURE) message after

having sent (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the "Description of

the Uplink Packet Channel Assignment" optional IE.

� After having sent (through the BTS) 44.018 DTM ASSIGNMENT COMMAND message that includes the

"Description of the Uplink Packet Channel Assignment" optional IE, upon T3107 expiry, the BSC does not

receive neither DTM ASSIGNMENT FAILURE (on the old channel) nor ASSIGNMENT COMPLETE (on the new

channel) messages.






1 � 3 � 55

� UL TBF in EDA mode:


QoS Indicators, EDA Mode B10

P596Number of UL TBF that have used at least one time the EDA mode during their lifetime

NB_EDA_USED_UL_TBF

P597Number of UL TBF belonging to mobile stations allowed to use the EDA mode

NB_EDA_ALLOWED_UL_TBF

P598Number of reallocations between DA and EDA modes for UL TBFNB_DA_EDA_REALLOC_UL_TBF

P595Cumulated overall time of UL TBF in active state operating in EDA modeCUMULATED_TIME_ACTIVE_UL_CONNECTED_TIME_EDA_MODE







1 � 3 � 56


Dual Transfer Mode (DTM), Exercise

� In configuration GPRS_B10-2.s

� Open Scenario 2, Scenario 3, Scenario 4

� In each case, is this an UL or a DL TBF establishment ?

� In each case, is there a TCH change ?

Time allowed:

30 minutes

B10






1 � 3 � 57

2 Data Transfer Progress






1 � 3 � 58


TBF Progress

Data Transfer established

Data Transfer released

Data transfer resumption(DL TBF and UL)

TBF resource re-allocation

RLCs blocks transfer

A TBF is considered “in progress” after it has been allocated successfully and before a release of this TBF is

triggered.

When a TBF is in progress, the following processes are or can be performed:

� The transfer of data is on-going:

� useful RLC blocks.

� LLC dummy commands

� The TBF resources are re-allocated.

� The transfer of data is resumed






1 � 3 � 59


Data Transfer Resumption during a DL TBF in Delayed Phase

DL transfer / Active phase

DL transfer / Delayed phase

MS MFS

DL transfer / Active phase

last useful RLC data block, polling

(EGPRS) Packet DL Ack/Nack

one but last useful RLC data block

Dummy block, polling

Packet DL Ack/Nack

Dummy block, polling

Packet DL Ack/Nack

T_DELAYED_DL_TBF_POL

LLC PDU

SGSN

new useful last RLC data block

useful last RLC data block

P422

T_DELAYED_DL_TBF_REL=


P421

P421

T_DELAYED_DL_TBF_POL_INITIAL


stop stop

start

A data transfer resumption is not a real TBF establishment since the TBF established previously with the MS

being in Delayed phase is re-activated. During the Delayed DL TBF phase, the BSS sends Dummy LLC UI

commands to the MS leading to periodic sending of RLC blocks containing these dummy LLC data.

As the application data transfer is burstly in a GPRS network (download of a web page made of a lot of

components (text, pictures)), it is very important to provide the way to resume a DL transfer of LLC PDUs

using the same radio resources already established rather than to re-establish again the DL TBF with the MS.

Timers

� T_DELAYED_DL_TBF_POL_INITIAL is the duration between the last useful RLC block sent to the MS

(eventually completed with a Dummy UI command) and the first Dummy UI command block sent during the

DL TBF delayed phase.

� T_DELAYED_DL_TBF_POL_INITIAL = 60 ms (default value). It cannot be set at the OMC-R level. The Min value of 60 ms is needed to ensure that T_DELAYED_DL_TBF_POL_INITIAL >= T_MIN_POLL

� T_DELAYED_DL_TBF_POL is the duration between the 2 consecutive Dummy UI command blocks

sent during the DL TBF delayed phase.

� T_DELAYED_DL_TBF_ POL = 200 ms (default value). It cannot be set at the OMC-R level.

� t_delayed_dl_tbf_rel is the maximum time during which the DL TBF stays in Delayed phase before being

actually released. It corresponds to the typical response time of a network server as seen from this MFS.

� t_delayed_dl_tbf_rel = T_NETWORK_RESPONSE_TIME = 1600 ms (default value). It can be set at

the OMC-R level.

� T_MIN_POLL: Minimum time between two consecutive polling requests .






1 � 3 � 60

� The UL transfer can resume at any time during the extended phase


Data Transfer Resumption during a UL TBF in Extended Phase

P. UL Ack/Nack (FAI=0, SSN = n+1)

RLC/MAC block (BSN=n, CV=0)

LLC PDU (last LLC)

T_MAX_EXTENDED_UL

USF

Dummy RLC data block

MS MFS SGSN

USF


USF

RLC/MAC block (BSN=n+1)

start

stop

USF

RLC/MAC block (BSN=n+2)

...

Active UL data transfer

Extended UL data transfer

Active UL data transfer

LLC PDU

P462

P462






1 � 3 � 61


TBF Resources Re-allocation

� 4 different TBF reallocations are permanently activated:

� T1: reallocation to maintain a TBF alive despite the CS preemption of someRTSs or of some GCHs in the cell

� T2: reallocation of an on-going TBF when establishing a concurrent TBF

� T3: reallocation useful to� Establish a new M-EGCH link for one of the TRXs of the cell

� Perform a “radio de-fragmentation” process

� Provide a higher throughput, if it is possible, to a TBF

� T4: reallocation to move a UL GPRS TBF sharing one PDCH with a DL EGPRS TBF onto PDCHs which do not support a DL EGPRS TBF. It concerns only GPRS TBFs

The scope of the T3 reallocation has been extended:

� To establish a new M-EGCH link for one of the TRXs of the cell.

� To perform a “radio defragmentation” process (i.e. to improve the TBF’s radio resource usage in the cell. The goal is that the PDCHs supporting the TBFs in the cell are always the first (or “left-most”)

allocated PDCHs of the cell). In particular, this will limit the risks that the TBFs are impacted by a CS

preemption.

� To provide a higher throughput, if it is possible, to any TBF in the cell.

� A higher throughput can be provided to a TBF by just changing its PDCH allocation (even if its

number of RTSs keeps the same). Typically, the throughput will be higher if the TBF is less

multiplexed (with other TBFs) on the new PDCHs.

� But the T3 reallocation will also enable to increase the number of RTSs of a TBF in the following

cases:

� for the MSs whose traffic type was “signalling” and has passed to “data” in RRM-PCC,

� or following the reception of an RR Allocation Indication message from the BSC allocating some

new RTSs in the cell






1 � 3 � 62


TBF Re-allocation of the 2 UL and DL TBFs on-going

MS_TIME_TO_SWITCH_TO_NEW_PDCH+

RRBP delay

DL:P403aUL:P404a

T1

DL:P405aUL:P406a

DL:P403cUL:P404c

T3

DL:P405cUL:P406c

DL:P403dUL:P404d

T4

DL:P405dUL:P406d

UL and DL Data transfer (new resources)

UL and DL Data transfer (old resources)

RLC data block

RLC data block

Packet timeslot reconfigure, polling

Packet control ack

the MS switches to the new resources

(max. 40 ms)

MS MFS

RLC data block

RLC data block

PACCHDL of DL TBF

PDTCHUL

PDTCHDL

PACCHUL of DL TBF

During the re-allocation procedure, the set of PDCHs allocated to the UL or/and DL TBF are modified. The following resources can be modified as well:

� the timing advance slot and index of the UL or/and DL TBFs,

� the PACCH slot of the UL or/and DL TBFs,

� the USFs allocated to the UL TBF,

� the UL or/and DL TFI.

During the radio resource re-allocation procedure:

� the TBF mode can not be modified.

� the EGPRS window size cannot be decreased. However the EGPRS window size in the DL (resp. UL) must be increased in case the number of time slots allocated to the MS in the DL (resp. UL) increases.

Timers

MS_TIME_TO_SWITCH_TO_NEW_PDCH: the time a Mobile Station needs to switch to the assigned PDCHs after acknowledging a (re)assignment message (PACKET DOWNLINK ASSIGNMENT, PACKET UPLINK ASSIGNMENT or PACKET TIMESLOT RECONFIGURE).

� MS_TIME_TO_SWITCH_TO_NEW_PDCH = 40 ms (default value). It cannot be set at the OMC-R level.

�The 3GPP standard mandates the MS to switch to the new resources in 40 ms but some MSs can take more time.

Let us consider that an MS has 2 TBFs on-going in both UL and DL directions but is candidate for re-allocation in the UL direction only (T1 or T3 or T4):

� then the counter of re-allocation request in the DL direction is also incremented .

� At the end of the UL re-allocation procedure, the counter of DL re-allocation success is incremented whether the UL re-allocation has been successful or not because the counter of re-allocation request in the DL direction has been previously incremented.

Same consideration can be done when an MS has 2 TBFs on-going in both UL and DL directions but is candidate for re-allocation in the DL direction only (T1 or T3 or T4).

The MFS starts timer T_ACK_WAIT after sending a Packet Timeslot Reconfigure message to wait for MS acknowledgement (Packet Control Ack message).

� If Packet Control Ack is not received, the MS resends the Packet Timeslot Reconfigure message.

� If after the MAX_RETRANS_DL+1 attempts the MS has not acknowledged the resource re-allocation then both DL and UL are released.






1 � 3 � 63


TBF Re-allocation of the Only TBF On-Going (DL or UL)


RRBP delay

DL:P403aUL:P404a

T1

DL:P405aUL:P406a

DL:P403cUL:P404c

T3

DL:P405cUL:P406c

DL:P403dUL:P404d

T4

DL:P405dUL:P406d

DL/UL Data transfer (new resources)

DL/UL Data transfer (old resources)

RLC data block

RLC data block

Packet downlink/uplink Assignment, polling

Packet control ack

the MS switches to the new resources (max. 40 ms)

MS MFS

RLC data block

RLC data block

PACCHDL of DL TBF / PACCHDL of UL TBF

PDTCHUL

PDTCHDL

PACCHUL of DL TBF / PACCHUL of UL TBF

The MFS starts timer T_ACK_WAIT after sending a Packet Downlink/Uplink Assignment message to wait for

MS acknowledgement (Packet Control Ack message):

� If Packet Control Ack is not received the MS resends the Packet Downlink/Uplink Assignment message.

� If after the MAX_RETRANS_DL+1 attempts the MS has not acknowledged the resource re-allocation then

the on-going DL/UL is released.






1 � 3 � 64


TBF Re-alloc of On-Going UL TBF on DL TBF Establishment


RRBP delay

P404b

T2

P406b


UL Data transfer (old resources)

RLC data block


Packet control ack


MS MFS

RLC data block

RLC data block

PACCHDL of UL TBF

PDTCHUL

PACCHUL of UL TBF

LLC PDU

PDTCHUL

PDTCHDL

The MFS starts timer T_ACK_WAIT after sending a Packet Timeslot Reconfigure message to wait for MS

acknowledgement (Packet Control Ack message):

� If Packet Control Ack is not received the MS resends the Packet Timeslot Reconfigure message.


both DL and UL are released.






1 � 3 � 65


TBF Re-alloc of On-Going DL TBF on UL TBF Establishment


RRBP delay

P403b

T2

P405b


DL Data transfer (old resources)

RLC data block


Packet control ack


MS MFS

RLC data block

RLC data block

PACCHDL of DL TBF

PDTCHDL

PACCHUL of DL TBF

PDTCHUL

PDTCHDL

Packet DL Ack/Nack with Channel requestPACCHUL of DL TBF

The MFS starts timer T_ACK_WAIT after sending a Packet Timeslot Reconfigure message to wait for MS

acknowledgement (Packet Control Ack message).

� If Packet Control Ack is not received the MS resends the Packet Timeslot Reconfigure message.


both DL and UL are released.






1 � 3 � 66


Exercise

� Exercise: Using the trace 3, find the time when the DL transfer is

resumed

Time allowed:

30 minutes






1 � 3 � 67


TBF Resource Re-allocation, Failures

TBF resource re-allocation FAILURE

no new PDCH allocation can

be foundRadio pb BSS pb

External TBF release request

SuspendCell

reselection






1 � 3 � 68

� T1 case

� counter =

� if no new PDCH allocation can be found then the TBF marked for soft preemption will be released at T_PDCH_PREEMPTION expiry

� T2/T3/T4 cases

� counter =

� if no new PDCH allocation can be found then the on-going TBF continue with its current PDCH allocation

DL:P423a

UL:P424b/P424c/P424d

UL:P424a

DL:P423b/P423c/P423d


TBF Resources Re-allocation, Failures, no New PDCH

T3 re-allocation conditions






1 � 3 � 69


TBF Resources Re-allocation, Failures, Radio

DL:P407aUL:P408a

T1

DL:P407cUL:P408c

T3

DL:P407dUL:P408d

T4

UL and/or DL Data transfer (old resources)

RLC data block

RLC data block

Packet timeslot reconfigure, polling or,Packet downlink assignment or,Packet uplink assignment

Packet control ack

MS MFS

PDTCCHUL

PDTCHDL

PACCHUL of DL TBF

T_ACK_WAITexpiry

DL:P407bUL:P408b

T2

All these counters are incremented when the last MAX_DL_RETRANS+1 re-allocation attempt has failed

(Packet Control Ack message not received from the MS).

Re-allocation failures due to radio can be due to a problem on the DL path.

In case of trigger T2, the re-allocation failure of the TBF also leads to an establishment failure due to radio

of the TBF to be established in the opposite direction.






1 � 3 � 70


TBF Resources Re-alloc, Fail, External Req., BSS

� External request



UL and/or DL Data transfer (old resources)

RLC data block

RLC data block

Packet timeslot reconfigure, polling or,Packet downlink assignment or,Packet uplink assignment

MS suspend

MS MFS

PDTCCHUL

PDTCHDL

GSL

T_ACK_WAIT

BSC SGSN

Flush-LLOROR

DL:P425aUL:P426a

T1

DL:P425cUL:P426c

T3

DL:P425dUL:P426d

T4

DL:P425bUL:P426b

T2

"External Stop"

Re-allocation failures due to radio can be due to a problem on the DL path.

In case of trigger T2, the re-allocation failure of the TBF also leads to an establishment failure due to radio

of the TBF to be established in the opposite direction.






1 � 3 � 71


QoS Indicators

� DL and UL TBF progress

TBF establishment

TBF statistics:

-duration, number, throughput,

- distribution

time

TBF release

Delayed DL TBF: active/delayed phase,

transfer resumption

TBF resources re-allocation

Triggers T1. T2. T3.T4

Number of candidate TBFs

Number of successes and success rate

Failures: congestion, radio, BSS,

external request

modified B10






1 � 3 � 72

� DL and UL TBF progress: TBF statistics


QoS Indicators, TBF Statistics

TBF statistics Downlink Uplink

Average GPRS TBF duration in ack mode

(P52a / 10) / (P90a + P90b + P90c + P90d + P90e + P90f)

Average GPRS TBF duration in ack mode

(P129a / 10) / (P30a + P30b + P30c)

Average GPRS TBF duration in nack mode

(P52b / 10) / (P90a + P90b + P90c + P90d + P90e + P90f)

Average GPRS TBF duration in nack mode

(P129b / 10) / (P30a + P30b + P30c)

Average EGPRS TBF duration in ack mode

(P52c / 10) / (P90a + P90b + P90c + P90d + P90e + P90f)

Average EGPRS TBF duration in ack mode

(P129c / 10) / (P30a + P30b + P30c)

Average EGPRS TBF duration in nack mode

(P52d / 10) / (P90a + P90b + P90c + P90d + P90e + P90f)

Average EGPRS TBF duration in nack mode

(P129d / 10) / (P30a + P30b + P30c)

Maximum number of TBF simultaneously established

p35 Maximum number of TBF simultaneously established

p39

Average number of TBF simultaneously established

p36 / 10 Average number of TBF simultaneously established

p40 / 10

Average useful throughput in kbit/s at RLC level per TBF

Σ CELL (P55a*160 + P55b*240 + P55c*288 + P55d*400 + P55e*176 + P55f*224 + P55g*296 + P55h*352 + P55i*448 + P55j*592 + (P55k*896 + P55l*1088 + P55m*1184)/2) / ((P52a + p52c)*1000)

Average useful throughput in kbit/s at RLC level per TBF

Σ CELL (P57a*160 + P57b*240 + P57c*288 + P57d*400 + P57e*176 + P57f*224 + P57g*296 + P57h*352 + ( P57i*448 + P57j*592 + (P57k*896 + P57l*1088 + P57m*1184)/2)) / ((P129a + P129c)*1000)

KPI KPI

The max nb of TBFs simultaneously established is meaningful per hour or per day.

The average nb of TBFs simultaneously established is less reliable due to the difference between the gauge

polling period and the average TBF duration.

Note : The RLC blocks retransmissions are not counted in both directions.






1 � 3 � 73


QoS Indicators, TBF Statistics [cont.]

� DL and UL TBF progress: TBF statistics

B10

P461Cumulated overall time of UL TBF connections (in active state or extended phase).

CUMULATED_ACT_EXT_UL_CONNECTION_TIME

P452

Cumulated time during which a DL TBF established for GMM signalling purposes uses a PDCH (in GPRS or EGPRS mode), for all TBFs of the cell.

CUMULATED_TIME_PDCH_DL_TBF_GMM_SIG_CELL

P595Cumulated overall time of UL TBF in active state operating in EDA mode

CUMULATED_TIME_ACTIVE_UL_CONNECTED_TIME_EDA_MODE

P451bCumulated time during which an DL TBF uses one PDCH, for all PDCHs of the TBF, and for all TBFs of the cell (in GPRS or EGPRS mode).

CUMULATED_TIME_PDCH_DL_TBF_CELL

P451aCumulated time during which an UL TBF uses one PDCH, for all PDCHs of the TBF, and for all TBFs of the cell (in GPRS or EGPRS mode).

CUMULATED_TIME_PDCH_UL_TBF_CELL


new B10

P452:

For a given DL TBF, this counter is started at the establishment of the DL TBFs established to carry GMM

signaling traffic to the MS. It is stopped at the end of the active phase of the DL TBF or on receipt of a DL

LLC PDU without the T-bit set.

P451:

Note: Active , delayed, extended phases of the TBF are taken into account (only).






1 � 3 � 74


QoS Indicators, Distributions

� Distribution based on TBF duration

DefinitionULDL

P453a_1

P453a_2

P453a_3

P453a_4

P453a_5

P453a_6

P453a_7

P453a_8

P453a_9

P453a_10

Tenth interval of the distribution on duration of DL/UL TBFs.

For DL It contains :

number of DL TBFs whose duration is in duration band 10

Duration band 10 is defined by :

PD_DL_TBF_DURATION_THR_9<= duration < PD_DL_TBF_DURATION_THR_10

P453b_10

Third cell of the duration on DL/UL TBF duration.P453b_3

Second cell of the duration on DL/UL TBF duration.P453b_2

Seventh cell of the duration on DL/UL TBF duration.P453b_7

Sixth cell of the duration on DL/UL TBF duration.P453b_6

Fifth cell of the duration on DL/UL TBF duration.P453b_5

Fourth cell of the duration on DL/UL TBF duration.P453b_4

First cell of the duration on DL/UL TBF duration.P453b_1

Eighth cell of the duration on DL/UL TBF duration.P453b_8

Ninth cell of the duration on DL/UL TBF duration.P453b_9

Note:

DL TBF in GPRS and EGPRS mode, in RLC acknowledged and in RLC unacknowledged mode are taken into

account. Only the active phase of the TBF is taken into account.

Default OMC-R parameter values in seconds:

� PD_DL_TBF_DURATION_THR_1 = 1639

� PD_DL_TBF_DURATION_THR_2 = 3277.5








� PD_DL_TBF_DURATION_THR_10 = 16384 (cannot be modified at the OMC-R)






1 � 3 � 75


QoS Indicators, Distributions [cont.]

� Distribution based on LLC volume

DefinitionULDL

P454a_1

P454a_2

P454a_3

P454a_4

P454a_5

P454a_6

P454a_7

P454a_8

P454a_9

P454a_10

Tenth interval of the distribution on volume of DL/UL TBFs.


number of DL TBFs whose LLC volume (in RLC ack mode only) is in LLC volume band 10.

LLC volume band 10 is defined by :

PD_DL_TBF_VOLUME_THR_8<= LLC volume < PD_DL_TBF_VOLUME_THR_9

P454b_10

Third cell of the distribution on volume of DL/UL TBF.P454b_3

Second cell of the distribution on volume of DL/UL TBF.P454b_2

Seventh cell of the distribution on volume of DL/UL TBF.P454b_7

Sixth cell of the distribution on volume of DL/UL TBF.P454b_6

Fifth cell of the distribution on volume of DL/UL TBF.P454b_5

Fourth cell of the distribution on volume of DL/UL TBF.P454b_4

First cell of the distribution on volume of DL/ULTBF.P454b_1

Eighth cell of the distribution on volume of DL/UL TBF.P454b_8

Ninth cell of the distribution on volume of DL/UL TBF.P454b_9

Only the active phase of the TBF is taken into account.

Default OMC-R parameter values in bytes:

� PD_DL_TBF_VOLUME_THR_1 = 10 000 000

� PD_DL_TBF_ VOLUME _THR_2 = 20 000 000








� PD_DL_TBF_ VOLUME _THR_10 = 100 000 000 (cannot be modified at the OMC-R)






1 � 3 � 76



� Distribution based on GPRS LLC Throughput per session

B10

DefinitionULDL

P532a_1

P532a_2

P532a_3

P532a_4

P532a_5

P532a_6

P532a_7

P532a_8

P532a_9

P531a_10

Tenth class of the distribution on number of GPRS DL/UL LLC throughput.

It contains :

1) number of GPRS DL/UL LLC throughput whose throughput is in EGPRS LLC throughput class 10.

GPRS LLC throughput class 10 is defined by :

GPRS_LLC_throughput_THR_9<= LLC throughput < GPRS_LLC_throughput_THR_10

P532b_10

Third class of the distribution on number of GPRS DL/UL LLC throughputP532b_3

Second class of the distribution on number of GPRS DL/UL LLC throughputP532b_2

Seventh class of the distribution on number of GPRS DL/UL LLC throughputP532b_7

Sixth class of the distribution on number of GPRS DL/UL LLC throughputP532b_6

Fifth class of the distribution on number of GPRS DL/UL LLC throughputP532b_5

Fourth class of the distribution on number of GPRS DL/UL LLC throughputP532b_4

First class of the distribution on number of GPRS DL/UL LLC throughputP532b_1

Eighth class of the distribution on number of GPRS DL/UL LLC throughputP532b_8

Ninth class of the distribution on number of GPRS DL/UL LLC throughputP532b_9

Parameter values in kbits/s (cannot be modified at the OMC-R):

� GPRS_LLC_THROUGHPUT_THR_1= 10

� GPRS_LLC_THROUGHPUT _THR_2 = 20














1 � 3 � 77



� Distribution based on EGPRS LLC Throughput per session

B10

tenth class of the distribution on number of EGPRS DL/UL LLC throughputP531a_10P531b_10

DefinitionULDL

P531a_1

P531a_2

P531a_3

P531a_4

P531a_5

P531a_6

P531a_7

P531a_8

P531a_9

P531a_11

Eleventh class of the distribution on number of EGPRS DL/UL LLC throughput.

It contains :

1) number of EGPRS DL/UL LLC throughput whose throughput is in EGPRS LLC throughput class 11.

EGPRS LLC throughput class 11 is defined by :

EGPRS_LLC_throughput_THR_10<= LLC throughput < EGPRS_LLC_throughput_THR_11

P531b_11

Third class of the distribution on number of EGPRS DL/UL LLC throughputP531b_3

Second class of the distribution on number of EGPRS DL/UL LLC throughputP531b_2

Seventh class of the distribution on number of EGPRS DL/UL LLC throughputP531b_7

Sixth class of the distribution on number of EGPRS DL/UL LLC throughputP531b_6

Fifth class of the distribution on number of EGPRS DL/UL LLC throughputP531b_5

Fourth class of the distribution on number of EGPRS DL/UL LLC throughputP531b_4

First class of the distribution on number of EGPRS DL/UL LLC throughputP531b_1

Eighth class of the distribution on number of EGPRS DL/UL LLC throughputP531b_8

Ninth class of the distribution on number of EGPRS DL/UL LLC throughputP531b_9

Parameter values in kbits/s (cannot be modified at the OMC-R):

� EGPRS_LLC_THROUGHPUT_THR_1= 20

� EGPRS_LLC_THROUGHPUT _THR_2 = 40















1 � 3 � 78



� Distribution based on PDCH usage

DefinitionULDL

P455a_1

P455a_2

P455a_3

P455a_4

P455a_5

P455a_6

P455a_7

P455a_8

P455a_9

P455a_10

Tenth interval of the distribution on units of PDCH allocated to DL/UL TBFs.


number of DL TBFs whose number of PDCH allocated units is in PDCH units band 10.

PDCH units band 10 is defined by :

PD_DL_PDCH_UNIT_ALLOC_THR_9<= allocated PDCH units < PD_DL_PDCH_UNIT_ALLOC_THR_10

P455b_10

Third cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_3

Second cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_2

Seventh cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_7

Sixth cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_6

Fifth cell of the distribution on units of PDCH allocated to DL/UL TBFs.P454b_5

Fourth cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_4

First cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_1

Eighth cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_8

Ninth cell of the distribution on units of PDCH allocated to DL/UL TBFs.P455b_9

UL

This distribution measures the number of PDCH units assigned to the MS in UL at the release of the UL TBF.

An UL PDCH unit represents the percentage of the PDCHs that is used by the assigned UL TBF.

This distribution is computed at the release of each UL TBF (i.e. indication of reception of

acknowledgement of final

PUAN).

DL

This distribution measures the number of PDCH units assigned to the MS in DL at the release of the DL TBF.

A DL PDCH unit represents the percentage of the PDCHs that is used by the assigned DL TBF.

This distribution is computed at the release of each DL TBF (i.e. at the expiry of timer T3192).






1 � 3 � 79


QoS Indicators, Delayed DL TBF

� DL and UL TBF progress: Delayed DL TBF

Delayed DL TBFCumulated time of active DL GPRS TBFconnections

P52a + P52b

Cumulated time of active DL EGPRS TBFconnections

P52c + P52d

Percentage of time during which the DL TBFconnections are in the “active” state

(P52a+P52b+P52c+P52d) / P16 * 100

Percentage of time during which the DL GPRSTBF connections are in the “active” state

(P52a + P52b) / P16 *100

Percentage of time during which the DLEGPRS TBF connections are in the “active”state

(P52c + P52d) / P16 * 100

Number of DL TBF transfer resumptions indelayed release state

P422

Rate of DL TBF transfer resumptions perestablished DL TBF

P422 / (P90a + P90b + P90c + P90d + P90e + P90f)

Number of DL RLC blocks containing onlydummy LLC UI Command PDU on PDTCH

P421

Number of DL RLC blocks sent on PDTCH P350aRate of RLC blocks containing only dummyLLC UI commands on DL PDTCH

P421 / P350a






1 � 3 � 80


QoS Indicators, Other Throughput Statistics

INDICATOR AVERAGE USEFUL THROUGHPUT PER CELL

DEFINITION Average of useful throughput on DL or UL PDTCH at RLC layer

FORMULA DOWNLINK Σ CELL (P55a*160 + P55b*240 + P55c*288 + P55d*400 + P55e*176 + P55f*224 + P55g*296 + P55h*352 +

P55i*448 + P55j*592 + (P55k*896 + P55l*1088 + P55m*1184)/2) / (PERIOD*1000)

FORMULA UPLINK Σ CELL (P57a*160 + P57b*240 + P57c*288 + P57d*400 + P57e*176 + P57f*224 + P57g*296 + P57h*352 +

P57i*448 + P57j*592 + (P57k*896 + P57l*1088 + P57m*1184)/2)) / (PERIOD*1000)

THRESHOLD

COMMENT New formulas in B9 to take into account the new coding schemes in UL.

DL: The DL retransmitted blocks and blocks containing LLC dummy UI commands are not counted.

UL: The UL retransmissions are not counted. RLC ack mode only is considered.

REF NAME TRPDDA, TRPDUA UNIT Kbits/second

INDICATOR AVERAGE USEFUL THROUGHPUT PER PDCH

DEFINITION Average of useful throughput on DL or UL PDTCH at RLC level per PDCH in RLC acknowledged mode.

FORMULA DOWNLINK Σ CELL (P55a*160 + P55b*240 + P55c*288 + P55d*400 + P55e*176 + P55f*224 + P55g*296 + P55h*352 +

P55i*448 + P55j*592 + (P55k*896 + P55l*1088 + P55m*1184)/2) / (P38e*1000)

FORMULA UPLINK Σ CELL (P57a*160 + P57b*240 + P57c*288 + P57d*400 + P57e*176 + P57f*224 + P57g*296 + P57h*352 +

P57i*448 + P57j*592 + (P57k*896 + P57l*1088 + P57m*1184)/2) / (P38f*1000)

THRESHOLD

COMMENT New formula in B9 to take into account the new coding schemes in UL.The RLC blocks retransmissions are not

counted in both directions. Reference Time: Cumulated time during which the PDCHs are established.

REF NAME TRPDDPDA, TRPDUPDA UNIT Kbits/second






1 � 3 � 81

DL TBF state

05000

100001500020000250003000035000400004500050000

14/08

/2003

16/08

/2003

18/08

/2003

20/08

/2003

22/08

/2003

24/08

/2003

26/08

/2003

28/08

/2003

30/08

/2003

01/09

/2003

03/09

/2003

05/09

/2003

07/09

/2003

09/09

/2003

11/09

/2003

13/09

/2003

01020304050607080 Delay-

>ActiveSuccess

% Efficiency

% Active

� On RNO graphs:

� % Efficiency = Rate of DL TBF resumptions per DL TBF establishment

� % Active = Percentage of time during which the DL TBF connections are in the active state


QoS Indicators, DL TBF states, Graph

The typical values of the Efficiency rate and Active rate:

� Efficiency rate = 40%, 60%

� Active rate = 15%, 20%






1 � 3 � 82

� TBF resource re-allocation for each trigger

time

Resource re-allocation Request

Preparation efficiency rateFailures cause

• No PDCH can be found

Resource re-allocation Attempt

Nb of TBF candidate resource re-allocations

Resource re-allocation Success

Ratio of triggers


QoS Indicators, TBF Resources Re-allocation

Execution efficiency rateFailures causes

• Radio problems (real drop)

• External Stop

• BSS problem (real drop)

External requests: FLUSH_LL received from the SGSN, Suspended from the MS.

Split between Preparation and Execution phases is driven by the fact that the problems to be interpreted

during re-allocation are relating to the Trigger type.

A TBF Re-allocation is analogue to an Intra cell HO in GPRS.






1 � 3 � 83

� DL and UL TBF progress: Resources re-allocation T1

TBF resources re-allocation : trigger T1 Downlink Uplink

Nb of TBF candidate for resource realloc P403a Nb of TBF candidate for resource realloc P404a Resource realloc ratio due to trigger T1 P403a / (P403a + P403b +

P403c + P403d) Resource realloc ratio due to trigger T1 P404a / (P404a + P404b +

P404c + P404d) Nb of resource realloc successes P405a Nb of resource realloc successes P406a Resource realloc success rate P405a / P403a Resource realloc success rate P406a / P404a Nb of resource realloc exec fail due to radio problems

P407a Nb of resource realloc exec fail due to radio problems

P408a

Resource realloc exec fail rate due to radio problems

P407a / P403a Resource realloc exec fail rate due to radio problems

P408a / P404a

Nb of resource realloc preparation failures because no PDCH could be found

P423a Nb of resource realloc preparation failures because no PDCH could be found

P424a

Resource realloc preparation fail rate due to lack of radio resources

P423a / P403a Resource realloc preparation fail rate due to lack of radio resources

P424a / P404a

Resource realloc prep efficiency rate (P403a - P423a) / P403a Resource realloc prep efficiency rate (P404a - P424a) / P404a Nb of resource realloc failures due external request (suspension request or Flush message) during exec of the realloc procedure

P425a Nb of resource realloc failures due external request (suspension request or Flush message) during exec of the realloc procedure

P426a

Nb of resource realloc failures due to BSS pb during exec of the realloc procedure

P403a - P423a - P425a - P407a - P405a

Nb of resource realloc failures due to BSS pb during exec of the realloc procedure

P404a - P424a - P426a - P408a - P406a

Exec fail rate due to BSS pb (P403a - P423a - P425a - P407a - P405a) / P403a

Exec fail rate due to BSS pb (P404a - P424a - P426a - P408a - P406a) / P404a

Resource realloc exec efficiency rate P405a / (P403a - P423a) Resource realloc exec efficiency rate P406a / (P404a - P424a)


QoS Indicators, TBF Resources Re-allocation, Trigger T1






1 � 3 � 84


TBF resources re-allocation : trigger T2Downlink Uplink

Nb of TBF candidate for resource realloc P403b Nb of TBF candidate for resource realloc P404bResource realloc ratio due to trigger T1 P403b/ (P403a + P403b +

P403c + P403d)Resource realloc ratio due to trigger T1 P404b / (P404a + P404b +

P404c + P404d)Nb of resource realloc successes P405b Nb of resource realloc successes P406bResource realloc success rate P405b / P403b Resource realloc success rate P406b / P404bNb of resource realloc exec fail due toradio problems

P407b Nb of resource realloc exec fail due toradio problems

P408b

Resource realloc exec fail rate due to radioproblems

P407b / P403b Resource realloc exec fail rate due to radioproblems

P408b / P404b

Nb of resource realloc preparation failuresbecause no PDCH could be found

P423b Nb of resource realloc preparation failuresbecause no PDCH could be found

P424b

Resource realloc preparation fail rate dueto lack of radio resources

P423b / P403b Resource realloc preparation fail rate dueto lack of radio resources

P424b / P404b

Resource realloc prep efficiency rate (P403b - P423b) / P403b Resource realloc prep efficiency rate (P404b - P424b) / P404bNb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P425b Nb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P426b

Nb of resource realloc failures due to BSSpb during exec of the realloc procedure

P403b - P423b - P425b -P407b - P405b


P404b - P424b - P426b -P408b - P406b

Exec fail rate due to BSS pb (P403b - P423b - P425b -P407b - P405b) / P403b

Exec fail rate due to BSS pb (P404b - P424b - P426b -P408b - P406b) / P404b

Resource realloc exec efficiency rate P405b / (P403b - P423b) Resource realloc exec efficiency rate P406b / (P404b - P424b)








1 � 3 � 85



Nb of TBF candidate for resource realloc P403c Nb of TBF candidate for resource realloc P404cResource realloc ratio due to trigger T1 P403c / (P403a + P403b +

P403c + P403d)Resource realloc ratio due to trigger T1 P404c / (P404a + P404b +

P404c + P404d)Nb of resource realloc successes P405c Nb of resource realloc successes P406cResource realloc success rate P405c / P403c Resource realloc success rate P406c / P404cNb of resource realloc exec fail due toradio problems

P407c Nb of resource realloc exec fail due toradio problems

P408c


P407c / P403c Resource realloc exec fail rate due to radioproblems

P408c / P404c


P423c Nb of resource realloc preparation failuresbecause no PDCH could be found

P424c


P423c / P403c Resource realloc preparation fail rate dueto lack of radio resources

P424c / P404c

Resource realloc prep efficiency rate (P403c - P423c) / P403c Resource realloc prep efficiency rate (P404c - P424c) / P404cNb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P425c Nb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P426c


P403c - P423c - P425c -P407c - P405c


P404c - P424c - P426c -P408c - P406c

Exec fail rate due to BSS pb (P403c - P423c - P425c -P407c - P405c) / P403c

Exec fail rate due to BSS pb (P404c - P424c - P426c -P408c - P406c) / P404c

Resource realloc exec efficiency rate P405c / (P403c - P423c) Resource realloc exec efficiency rate P406c / (P404c - P424c)








1 � 3 � 86



Nb of TBF candidate for resource realloc P403d Nb of TBF candidate for resource realloc P404dResource realloc ratio due to trigger T4 P403d / (P403a + P403b +

P403c + P403d)Resource realloc ratio due to trigger T4 P404d / (P404a + P404b +

P404c + P404d)Nb of resource realloc successes P405d Nb of resource realloc successes P406dResource realloc success rate P405d / P403d Resource realloc success rate P406d / P404dNb of resource realloc exec fail due toradio problems

P407d Nb of resource realloc exec fail due toradio problems

P408d


P407d / P403d Resource realloc exec fail rate due to radioproblems

P408d / P404d


P423d Nb of resource realloc preparation failuresbecause no PDCH could be found

P424d


P423d / P403d Resource realloc preparation fail rate dueto lack of radio resources

P424d / P404d

Resource realloc prep efficiency rate (P403d - P423d) / P403d Resource realloc prep efficiency rate (P404d - P424d) / P404dNb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P425d Nb of resource realloc failures due externalrequest (suspension request or Flushmessage) during exec of the reallocprocedure

P426d


P403d - P423d - P425d -P407d - P405d


P404d - P424d - P426d -P408d - P406d

Exec fail rate due to BSS pb (P403d - P423d - P425d -P407d - P405d) / P403d

Exec fail rate due to BSS pb (P404d - P424d - P426d -P408d - P406d) / P404d

Resource realloc exec efficiency rate P405d / (P403d - P423d) Resource realloc exec efficiency rate P406d / (P404d - P424d)








1 � 3 � 87


QoS Indicators

� DL and UL TBF progress for DTM capable MS

TBF establishment

time

TBF release

Cumulated time of DTM operation

for DTM capable MS

Cumulated time of dedicated mode

operation for DTM capable MS

Cumulated time of PTM operation for

DTM capable MS

B10

DTM ser

vice

penetra

tion !






1 � 3 � 88


QoS Indicators, Cumulated Time of Operation for DTM MS

� DL and UL TBF progress for DTM capable MS

B10

P504Cumulated time during which a DTM capable MS is operating in packet transfer mode

CUMULATED_DTM_PTM_TIME

P503Cumulated time during which a DTM capable MS is operating in dedicated mode

CUMULATED_DTM_DEDICATED_TIME

P502Cumulated time during which a DTM capable MS is operating in DTM mode

CUMULATED_DTM_TIME


P502:

� Starting: when in dedicated mode on the establishment of the first UL or DL TBF. (the first UL RLC data Blocks are

received from the MS (case of UL TBF) or the first Packet downlink Ack/Nack message is received from the MS (case of

DL TBF)).

� Stopping: when in DTM mode the CS session or PS session are , normally or abnormally, released.

Note:

� The common duration during which a UL and a DL are established is counted as one duration (UL and DL

common time durations are not cumulated).

� The time duration of all periods (active and delayed/extended) is taken into account.

P503:

� Starting: when the indication of start of a CS session is received (first BSCGP BSC Shared DTM Info Indication with

CS=1 received) or when, in DTM mode, PS session is, normally or abnormally, released.

� Stopping: when in dedicated mode, the first UL RLC data Blocks are received from the MS (case of UL TBF) or the

first Packet downlink Ack/Nack message is received from the MS (case of DL TBF) or when in dedicated mode, an

indication of stop of CS session is received (BSCGP BSC Shared DTM Info Indication with CS=0 received) or when in

dedicated mode, an indication of stop of CS session is received.

P504:Cumulated time duration of all UL / DL TBFs established over the Granularity period.

� Note: DTM capability of the MS is given in RA capabilities, which are known only:

� in case a DL LLC PDU has been received for this MS

� in case only an UL TBF exists, once the procedure for RA capability update is finished (provided

EN_RA_CAP_UPDATE=1)

� Note 1: This counter applies only to DTM capable MS not in dedicated mode.

� Note 2: This counter applies to both GPRS and EGPRS TBFs and to both ACK or UNACK mode.

� Note 3 : The time duration of all periods (active and delayed/extended) is taken into account.

� Note 4 : UL and DL TBF duration are not cumulated.

The time is provided in seconds with one significant value after the comma (i.e. ROUND(10x) / 10).






1 � 3 � 89

3 Data Transfer Release






1 � 3 � 90


TBF Release B10

TBF ReleaseTBF Release

Normal Release Acceptable Release Abnormal Release

Cell reselectionCell reselection

SuspendSuspend

PDCH FastPre-emption


Due to CS operationin DTM

Due to CS operationin DTM

RadioRadio

Re-allocationexecution failure

Re-allocationexecution failure

OthersOthers

BSSBSS

GbGb

new B10






1 � 3 � 91


Normal TBF Release

Normal TBF release

UL TBF release DL TBF release

Without Delayed Final PUAN

With Delayed Final PUAN

With Delayed DL TBF release

Without DL TBF Extension

With DL TBF Extension

With extended

UL TBF

DL TBF is said to have been extended in case of an UL TBF establishment during the DL TBF delayed release;

the DL delayed phase is extended up to the release of the UL TBF and restarted afterwards






1 � 3 � 92

� In case no DL TBF is established, it is better to delay the UL TBF release to be able to establish quickly a subsequent DL TBF on the PACCHDL of the delayed UL TBF rather than on CCCH or PCCCH

Active UL Data transfer

Packet uplink ack/nack (FAI=1)

all blocks acknowledged

P22

one but last useful RLC data block (CV=1)

MS MFS

PDTCHUL

SGSN

last useful RLC data block (CV=0)

PACCHDL

Packet control ack

last LLC PDU

P22

Packet uplink ack/nack (FAI=1), polling


UL TBF, Normal Release, without Delayed Final PUAN






1 � 3 � 93


T_DELAYED_FINAL_PUANexpiry

last block not acknowledged


P22

Packet uplink ack/nack (FAI=1), pollingPACCHDL last block acknowledged

Packet control ack


UL TBF, Normal Release, with Delayed Final PUAN

one but last useful RLC data block (CV=1)

MS MFS

PDTCHUL

SGSN


PACCHDL

last LLC PDU

Timer T_DELAYED_FINAL_PUAN corresponds to the duration during which the UL is maintained “alive” in

order to be able to establish a DL TBF on PACCH:

� T_DELAYED_FINAL_PUAN = 0.4 s (default value). It can be set at the OMC-R level.

� It should be long enough to let the server send its response to the uplink PDUs received from the MS,

while remaining short enough in order not to jeopardize the sending of further uplink PDUs by the MS.

� Setting T_DELAYED_FINAL_PUAN = 0 s leads to disable this feature.






1 � 3 � 94


T_MAX_EXTENDED_ULexpiry

last block not acknowledged


P22

Packet uplink ack/nack (FAI=1), pollingPACCHDL last block acknowledged

Packet control ack

one but last useful RLC data block (CV=1)PDTCHUL


PACCHDL

last LLC PDU

USF


USF



UL TBF, Normal Release, with Extended UL TBF






1 � 3 � 95

not last acknowledgement

Packet downlink ack/nack (FAI=0)

P9


DL TBF, Normal Release, Delayed DL TBF no Extension

one but last useful RLC data block (FBI=0)

MS MFS

PDTCHDL

last useful RLC data block (FBI=0), polling

PACCHULT_DELAYED_DL_TBF_REL

T_DELAYED_DL_TBF_POL_INITIALlast block not mentioned


Dummy UI command (FBI=0), pollingT_DELAYED_DL_TBF_POL


Dummy UI command (FBI=0), polling




T_DELAYED_DL_TBF_RELexpirylast block mentioned

last acknowledgement

Active DL data transfer

Delayed DL data transfer

DL TBF released

As soon as all the useful blocks have been transferred, the Delayed DL TBF release procedure is triggered in

order to allow:

� to send a coming LLC PDU frame using the same radio resources without being obliged to establish the DL

TBF again (T3192 running or not).

� the MS to establish a UL TBF on PACCH rather than on CCCH or PCCCH.

The DL TBF goes from Active state to Delayed state.

As the MS will trigger a local DL TBF release if it does not receive DL RLC data blocks (T3190 is running) the

MFS is scheduling Dummy UI command blocks in DL according to the following timers:

� T_DELAYED_DL_TBF_POL_INITIAL is the duration between the last useful RLC block sent to the MS

(eventually completed with a Dummy UI command) and the first Dummy UI command block sent during the

DL TBF delayed phase.

� T_DELAYED_DL_TBF_POL_INITIAL = 60 ms (default value). It cannot be set at the OMC-R level.

� 2 timers are used to define the period between 2 DL Dummy UIs sent to the MS:

� T_MIN_POLL (=60ms), in case of the MS is “alone” on the PDCH which carries the PACCH

� T_DELAYED_DL_TBF_POL (=200ms) in case of the MS is “multiplexed” on the PDCH which carries

the PACCH

� A global timer t_delayed_dl_tbf_rel monitors the whole Delayed DL TBF release procedure. At

t_delayed_dl_tbf_rel expiry, the DL TBF stays in Delayed phase before being actually released. This timer

corresponds to the typical response time of a network server as seen from this MFS.

� t_delayed_dl_tbf_rel = T_NETWORK_RESPONSE_TIME = 1600 ms (default value). It can be set at

the OMC-R level.






1 � 3 � 96


DL TBF, Normal Release, Delayed DL TBF with Extension

MS MFS

T_DELAYED_DL_TBF_RELis stopped

Packet downlink ack/nack (FAI=0)with Channel request

Dummy UI command (FBI=0), pollingT_DELAYED_DL_TBF_POL

Packet uplink ack/nack (FAI=1), polling

T_DELAYED_DL_TBF_POL_UL

T_DELAYED_DL_TBF_RELis restarted

Delayed DLTBF releaseis on-going

T_ACK_WAIT


USF Scheduling

UL RLC data block



T_DELAYED_DL_TBF_POL_UL

Delayed DLTBF releaseis extended

Packet control ack



UL TBF establishme

nt

UL TBF is

releasedDelayed DL TBF release is resumed from beginning

UL RLC data block

If a UL TBF is established during a Delayed DL TBF release phase then:

� the countdown of this Delayed DL TBF release phase is stopped (timer t_delayed_dl_tbf_rel).

� the Dummy UI command blocks are sent in the DL in order that the MS does not release the DL TBF.

The Delayed DL TBF release phase is said to be extended.

Two cases of UL TBF should be considered:

� “question-answer” traffic: corresponds to WAP services or WEB browsing where the UL command induced by the user are small and usually lead to a transfer of only one LLC PDU:

� The UL polling period induced by Dummy UI command scheduling is kept to T_DELAYED_DL_TBF_ POL.

� T_DELAYED_DL_TBF_POL_INITIAL = 60ms (default value). It cannot be set at the OMC-R level.

� Other cases: correspond to applications like UL FTP file transfer where a lot of LLC PDUs have to be transferred during the same TBF:

�The UL polling period induced by Dummy UI command sending is increased to T_DELAYED_DL_TBF_ UL in order to decrease the UL load due to the Delayed DL TBF release phase in favor of the UL FTP throughput .

� T_DELAYED_DL_TBF_POL_UL = 2 s (default value). It cannot be set at the OMC-R level.

As soon as the UL TBF is released, the Delayed DL TBF:

� the countdown of the Delayed DL TBF release procedure is resumed from the beginning (t_delayed_dl_tbf_rel restarted).

� the scheduling period of Dummy UI command blocks for the Delayed DL TBF is set back to T_DELAYED_DL_TBF_ POL.

At the end of a Delayed DL TBF procedure, the DL TBF is released and the counter P9 is incremented whether the Delayed DL TBF phase has been extended or not.






1 � 3 � 97


TBF Normal Release, Exercise

� Exercise1: Using the trace 1, find the duration between two consecutive Dummy UI command blocks during the Delayed DL TBF release procedure

� Exercise 2: Using trace number 9, find duration of the extended phase

Time allowed:

30 minutes






1 � 3 � 98


TBF Acceptable Release B10

Acceptable Release

Cell reselectionCell reselection SuspendSuspend PDCH FastPre-emption


CS operationin DTM

CS operationin DTM

MS is reselecting a neighbor cell while in PTM

MS is reselecting a neighbor cell while in PTM

MS is establishing a CS

connection while in PTM

MS is establishing a CS

connection while in PTM

PDCH carrying PACCH of the TBF is to be released

PDCH carrying PACCH of the TBF is to be released

CS connection while MS in PTM

CS connection while MS in PTM

Intercell or intracell HO

Intercell or intracell HO

Normal TCH release during

DTM

Normal TCH release during

DTM

new B10






1 � 3 � 99


TBF Acceptable Release, Cell Reselection, NC0 Scenario 1

MFS

serving cell

MFS

target cellMS

DL transfer

useful RLC data block, polling

Packet DL Ack/Nack

useful RLC data block


PDTCHDL

PACCHUL


SGSN

The MS decides for cell

reselection

LLC PDU(TLLI,new BVCI)

FLUSH-LL(TLLI,old BVCI)

FLUSH-LL ACK

(TLLI)

UL transfer establishment in the new cell

UL transferThe MS sends an LLC PDU to warn the SGSN about its new cell location

P434d

DL

P434c

UL

P396aP396b

N3105 ++

Counter P434d (resp.P434c) gives the number of DL (resp. UL) TBFs which have been released due to an NC0

reselection. It is therefore incremented in this scenario.

In this scenario where the FLUSH-LL message is received before the Radio Link Supervision counter N3105

reaches the limit, N3105 is stopped when the FLUSH_LL message is received.Therefore the TBF release is

not counted as an abnormal release due to radio. P302b_x (resp. P302c_x) is not incremented. Only P396a

(resp. P396b) counting the number of TBF release due to the reception of a FLUSH_LL message is

incremented.






1 � 3 � 100


TBF Acceptable Release, Cell Reselection, NC0 Scenario 2

MSMFS

serving cellDL transfer


Packet DL Ack/Nack



PDTCHDL

PACCHUL


SGSNMFS

target cell


reselection

LLC PDU

(TLLI,new BVCI)

FLUSH-LL

(TLLI,old BVCI)

FLUSH-LL ACK

(TLLI)



P434dP434c

N3105 ++

N3105 limit

DLUL

P302b_xP302c_xT_WAIT_FLUSH

DLUL

RADIO STATUS

Counter P434d (resp.P434c) gives the number of DL (resp. UL) TBFs which have been released due to an NC0

reselection. It is therefore incremented in this scenario.

In this scenario where the FLUSH-LL message is received after the Radio Link Supervision counter N3105

reaches the limit, the radio resources are released when N3105 reaches the limit. Therefore the TBF

release is counted as an abnormal release due to radio. P302b_x (resp. P302c_x) is incremented whereas

P396a (resp. P396b) is not. The timer T_WAIT_FLUSH is started when the abnormal TBF release is triggered.

When the FLUSH_LL message is received while T_WAIT_FLUSH is running then T_WAIT_FLUSH is stopped and

P434d (resp. P434c) is incremented.

In case the FLUSH_LL message is received after T_WAIT_FLUSH has expired then P434d (resp. P434c) is not

incremented but P302b_x (resp. P302c_x) is.






1 � 3 � 101


TBF Acceptable Release, Cell Reselection, NC2


UL transferMS sends an LLC PDU to warn the SGSN about its new cell location

MSMFS



Packet DL Ack/Nack


P396a


PDTCHDL

PACCHUL


P396b

SGSN

expiryPacket measurement report

PACCHUL

MFS

target cell

Better cell

⇓⇓⇓⇓MFS trigger

cell reselection Packet cell change order, polling

PACCHDLnew cell (BCCH,BSIC) Packet control ack

The MS switches to the new cell

T3158

T3158

Radio resources are released

locally

LLC PDU

(TLLI,new BVCI)

FLUSH-LL

(TLLI,old BVCI)

FLUSH-LL ACK

(TLLI)

T_ACK_WAIT

DL UL

T_WAIT_FLUSH

P434b P434a

The chart above corresponds to the typical scenario of an NC2 reselection.

The same P396a (resp. P396b) counter is incremented in case of a TBF release due to an NC0 reselection

provided that the FLUSH-LL message is received before a TBF drop is detected. This should almost always

happen in case of NC2 cell reselection since the Radio Link Supervision process is frozen after the BSS gets

the Acknowledgment of the Packet Cell Change Order message sent to the MS.

In case a TBF Abnormal Release is detected by the Radio Link Supervision process then P302b_x (resp.

P302c_x) as well as P434b (resp. P434a) is incremented but P396a (resp. P396b) is not.

T3158 = NC_REPORTING_PERIOD_T NC2 in PTM or NC_REPORTING_PERIOD_I in case of NC2 in PIM

= measurement report interval timer






1 � 3 � 102


TBF Acceptable Release, Cell Reselection, Counters

Cell reselection NC0+NC2P397

No TBF release TBF release

MS in PIM MS in PTM

TBF release due to flush

NC0+NC2

P396b / P396a

TBF release due to radio

P302c_x / P302b_x

TBF release due to cell reselection

NC2

P434a / P434b

NC0

P434c / P434d

Flush before T_Wait_Flush expiry

counter

UL TBF / DL TBF

No counter

incremented

after expiry

The chart above concerns the PM counters incremented during a cell reselection procedure.

P397 is incremented each time a FLUSH_LL is received by the MFS relating to a certain serving cell.

P396a, P396b, P434a, P434b, P434c and P434d are incremented only for TBF release during a cell

reselection procedure.

P302b_x and P302c_x are global counters relating to TBF abnormal release due to radio. They are

incremented when the TBF abnormal release is triggered due to a cell reselection or not.






1 � 3 � 103


TBF Acceptable Release, MS Suspend, Scenario 1

MS MFS

DL transfer


Packet DL Ack/Nack


MSC/VLR

P98c


PDTCHDL

PACCHUL


P98d

DL UL

SGSNBSC

The MS enters the CS dedicated mode

Suspend MS Suspend Suspend PDU

P98e P98f

DL TBF Release due to Suspend

DL UL

P98a P98b

The counter(s) P98c and/or P98d are incremented counts the number of MS SUSPEND messaged received for

a DL (resp UL) TBF.

If the TBF is released due to the reception of MS SUSPEND message then the counter P98a and/or P98b is

incremented,

The difference between P98a and P98e in DL (resp P98b and P98f in UL): see next slide.






1 � 3 � 104


TBF Acceptable Release, MS Suspend, Scenario 2

MS MFS

DL transfer


Packet DL Ack/Nack


MSC/VLR

P98c


PDTCHDL

PACCHUL


P98d

DL UL

SGSNBSC

Suspend MS Suspend

P98e P98f

Abnormal DL TBF Release

DL

P302b_x

T_WAIT_FLUSH

RADIO STATUS

If the TBF is released due to the reception of MS SUSPEND message then the counter P98e and/or P98f is

incremented, even if the TBF has been released before the reception of the suspend in the previous

T_WAIT_FLUSH seconds.

When TBF is released before the MFS receives the MS SUSPEND message, in this case the MFS increments the

Radio Problem related counter(s) P302b_x and/or P302c_x rather than the counter(s) P98a and/or P98b. In

this case the Radio related counter(s) is(are) incremented.

The counter(s) P98c and/or P98d are incremented in both cases since P98c (resp P98d) counts the number

of MS SUSPEND messaged received for a DL (resp UL) TBF.






1 � 3 � 105


TBF Acceptable Release, Fast Preemption

MS MFS

DL transfer


Packet DL Ack/Nack


P146


Packet TBF release

PDTCHDL

PACCHUL


PACCHDL

Traffic load ➚➚➚➚

⇓⇓⇓⇓The PDCH carrying

the PACCH of the TBF is released

P147

DL UL

A PDCH de-allocation following a PDCH preemption procedure can lead to a TBF release before the normal

end of the TBF if the PACCH of the related TBF is carried by the PDCH which is de-allocated.

This can be avoided thanks to the TBF Re-allocation procedure on Trigger T1. However if radio resources

are lacking the TBF Re-allocation can failed and the TBF is abnormally released.






1 � 3 � 106


TBF Acceptable Release, CS Connection while MS in PTM B10

[PACCH]

BSC Shared DTM Info Indication (7)

CS paging

DL

MS BTS BSC MFS

P509

Paging CS (2)

PTM (UL or/and DL TBF (1)

P510

SGSN MSC

Paging Request

IMSIPacket Paging Request (3)

Packet Paging Request (4)

SDCCH Assignment (5)

SCCP Connection (6)

UL

DTM Connection

T_WAIT_DTM

PTM

DTM

Dedicated

� The DTM MS is in uplink or/and downlink packet transfer mode.

� The MFS receives a CS paging from the SGSN and checks whether or not the MS is in packet transfer

mode.� As the MS is in packet transfer mode, the MFS forwards the CS paging to the MS in a Packet Paging

Request message on PACCH. The MFS starts the timer T_WAIT_DTM to monitor the MS access after the CS paging. At this stage, the MFS does not force the release of the UL TBF and lets the RLC layer detect the abnormal DL TBF release.

� On receipt of the Packet Paging Request message, the MS aborts its on-going UL TBF, leaves the packet transfer mode, and enters the dedicated mode.

� The MS requests a SDCCH resource. The BSC assigns to the MS a SDCCH resource. � The BSC requests an SCCP connection and forwards the MS classmark to the MSC. As soon as the MSC

knows the IMSI of the MS and that the MS is DTM capable, the MSC shall send the Common ID message to the BSC (assuming that the MSC supports DTM).

� On receipt of the Common ID, the BSC informs the MFS that the MS has just entered the dedicated mode (through the BSC Shared DTM Info Indication message). This message also includes the classmark of the MS. On receipt of the BSC Shared DTM Info Indication message, the MFS forces the release of the previous TBFs provided that they are still alive and stops T_WAIT_DTM timer.






1 � 3 � 107


TBF Acceptable Release, Intercell HO B10


DL

MSTarget

BTSBSC MFS

P509

DTM (1)

P510

SGSN MSC

HO Performed

HO execution (2)

UL

DTM Connection in the new cell

Serving

BTS

Old cell


New cell

Cell Update or RA Update

DTM

Dedicated

DTM

(incremented in the old cell)

� The MS is in Dual Transfer Mode.

� The MS performs its access in the new cell.

� At reception of BSCGP BSC Shared DTM info indication (CS_flag = 0, CS cause “intercell handover”) in the

old cell, the MFS deletes the MS context. � At reception of BSCGP BSC Shared DTM info indication (CS_flag = 1, CS cause “intercell handover”) in the

new cell, the MFS creates a new MS DTM context according to the information received from the BSC.






1 � 3 � 108


TBF Acceptable Release, TCH Release in DTM B10

BSC Shared DTM Info Indication (4) DL

MS BSC MFS

P509

DTM (1)

P510

SGSN MSC

Clear Command (2)

UL

DL or UL TBF establishment

BTS

Channel Release (3)

DTM

PTM

PIM

� The MS is in Dual Transfer Mode.

� The BSC receives a 48.008 Clear Command message to release the CS connection.

� The BSC sends to the MS a 44.018 Channel Release message. On receipt of the Channel Release message,

the MS starts timer T3110, disconnects the main signaling link, aborts its on-going TBFs and returns to

the packet idle mode (listening to the (P)CCCH). At this stage, the MFS does not force the release of the

on-going TBFs and lets the RLC layer detect the abnormal TBF releases. At the transition from the dual

transfer mode to the packet idle mode, the MS shall enter the Transfer non-DRX mode period.� Through the BSC Shared DTM Info Indication message, the BSC indicates to the MFS that the MS has left

just the dual transfer mode. This message is also used by the MFS to indicate that the MS has entered the Transfer non-DRX period. On receipt of the BSC Shared DTM Info Indication message, the MFS forces the release of the previous TBFs provided that they are still alive.






1 � 3 � 109


TBF Abnormal Release

Real radio problems

Acceptable Release

RadioRadio BSSBSS GbGb OthersOthers

Re-allocation execution failure

Real radio link failureBlocking Situation

Blocking Situation

new B10

Radio Link Failure

Radio Link Failure

Some SuspendSome Suspend

Some cell reselectionSome cell reselection

Stagnating window

Stagnating window

N3105

Tx Efficiency

N3101

N3103

N Polling EUTM

Real radio problems corresponds to:

� TBF release due to a radio resource reallocation failure

� TBF release due to the Suspend or Cell reselection cases which are counted as a TBF release due to radio

problem






1 � 3 � 110

� Radio link failure:

� Real Radio link failure:

� Coverage

� Interference

� Too low efficiency of RLC blocks transmission

� Some Suspend :

� Some Cell reselection :

� Re-allocation execution failure:


TBF, Abnormal Release, Radio

P302b_xDL P302c_xUL

DL

P407a+P407b+P407c+P407d

P408a+P408b+P408c+P408d

UL

P98c-P98aDL P98d-P98bUL

P434b+P434d-P396aDL P434a+P434c-P396bUL

A radio link failure can be due to a real radio problem like coverage, interference but also to undetected

problems at BSS level like bad hardware components, Abis microwave link transmission.

After a radio link failure, a RADIO STATUS message is sent to the SGSN on Gb interface with one of the following causes:

� “radio contact lost with the MS”: when the radio block transfer has been interrupted.� “radio link quality insufficient to continue the communication”: when the radio block transfer is not efficient enough.

Reminder:

� N3105 is the counter monitoring the radio link during a DL TBF. It is incremented each time a Packet

Downlink Ack/Nack message scheduled by the MFS is not received from the MS.

� N3101 is the counter monitoring the radio link during a UL TBF. It is incremented each time an up-link RLC

block scheduled by the MFS is not received from the MS.

� N3103 is the counter monitoring the normal end of a UL TBF. It is incremented each time the Final Packet

Control Ack message scheduled by the MFS at the end of the UL TBF is not received from the MS.






1 � 3 � 111

� Gb:

� BSS: no specific counter

� Other abnormal release cases:

� Blocking situation (MS error, too high UL traffic)

� Stagnating transmission window

(MS error, radio problem)


TBF, Abnormal Release, Gb, BSS, Others

P303a P303b

DL UL

P11 P24

DL UL

P385a P385b

.






1 � 3 � 112


Exercise

� Exercise 1: Using the trace 11, find which kind of TBF release is observed

� Exercise 2: Using the trace 13, find which kind of TBF release is observed

Time allowed:

30 minutes






1 � 3 � 113

� DL and UL TBF release

TBF establishment

time

TBF end Normal release rate

Acceptable release rate

Drop causes

PDCH fast preemption

Suspend procedure

Radio

Radio fail during resource re-alloc exec

BSS

Gb

Other problems: blocking situation +

N_stagnating window

Cell reselection


QoS Indicators B10

CS operation in DTMnew B10

modified B10






1 � 3 � 114

� DL and UL TBF release: Drop rate


QoS Indicators, KPI B10

A MODIFIER

P510 / (P30a + P30b + P30c + P508)Release rate due to CS operation in DTM

P509 / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Release rate due to CS operation in DTM

(P434a + P434c) / (P30a + P30b + P30c + P508)

Release rate due to Flush message

(P434b + P434d) / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Release rate due to cell reselection

P98b / (P30a + P30b + P30c + P508)Release rate due to suspend procedure from MS

P98a / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Release rate due to suspend procedure from MS

P147 / (P30a + P30b + P30c + P508)Release rate due to PDCH fast pre-emption

P146 / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Release rate due to PDCH fast pre-emption

(P30a + P30b + P30c + P508 - P22 -P147 - P98d - P434a - P434c - P510) / (P30a + P30b + P30c + P508)

Drop rate(P90a + P90b + P90c + P90d + P90e + P90f - P9 - P146 - P98c - P434b -P434d - P509) / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Drop rate

(P147 + P98d + P434a + P434c + P510) / (P30a + P30b + P30c + P508)

Acceptable release rate(P146 + P98c + P434b + P434d + P509) / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Acceptable release rate

P22 / (P30a + P30b + P30c + P508)Normal release rateP9 / (P90a + P90b + P90c + P90d + P90e + P90f + P506)

Normal release rate

UplinkDownlink

TBF releases and drops

KPI

KPI

KPI

KPI

KPI

KPI

new B10 new B10

.






1 � 3 � 115

� DL and UL TBF release: TBF drops


QoS Indicators, TBF Abnormal Release B10

(GPRS_UL_TBF_drop -

GPRS_UL_TBF_real_drop_radio -

GPRS_UL_TBF_drop_GB -

GPRS_UL_TBF_drop_N_stagnatingWindow -

GPRS_UL_TBF_drop_blocking)

/ GPRS_UL_TBF_success

BSS problem(GPRS_DL_TBF_drop -

GPRS_DL_TBF_real_drop_radio -

GPRS_DL_TBF_drop_GB -

GPRS_DL_TBF_drop_N_stagnatingWindow -

GPRS_DL_TBF_drop_blocking)

/ GPRS_DL_TBF_success

BSS problem

P303b / (P30a + P30b + P30c + P508)Blocking situationP303a / (P90a + P90b + P90c + P90d + P90e +

P90f + P506)

Blocking situation

P385b / (P30a + P30b + P30c + P508)N_StagnatingWindowP385a / (P90a + P90b + P90c + P90d + P90e +

P90f + P506)

N_StagnatingWindow

P24 / ( P30a + P30b + P30c + P508)Gb problemP11 / (P90a + P90b + P90c + P90d + P90e + P90f

+ P506)

Gb problem

(P408a + P408b + P408c + P408d) / (P30a + P30b

+ P30c + P508)

Radio failure during

radio resource realloc

execution

(P407a + P407b + P407c + P407d) / (P90a + P90b

+ P90c + P90d + P90e + P90f + P506)

Radio failure during

radio resource realloc

execution

(P302c_1 + P302c_2 + P302c_3 + P302c_4/ -

(P98d - P98b) - (P434a + P434c - P396b) + P408a

+P408b + P408c + P408d) / (P30a + P30b + P30c +

P508)

Real radio drop rateP302b_1 + P302b_2 - (P98c - P98a) - (P434b +

P434d - P396a) + P407a +P407b + P407c +

P407d) / (P90a + P90b + P90c + P90d + P90e +

P90f + P506)

Real radio drop rate

P302c_1 + P302c_2 + P302c_3 + P302c_4/ (P30a +

P30b + P30c + P508)

Radio problem : real

radio pb +

reselections

P302b_1 + P302b_2 / (P90a + P90b + P90c +

P90d + P90e + P90f + P506)

Radio problem : radio

link failure

UplinkDownlink

TBF drop causes

P302b and P302c have been removed in B10 and replaced by (P302b_1 + P302b_2) and (P302c_1 + P302c_2 +

P302c_3 + P302c_4).

On a DL TBF:

� Radio problem: N3105 exceeds the limit (6) or too low TX efficiency (<10%).

� Blocking situation: no reception of the PDAN with Final indicator = 1 at the end of the Downlink TBF

during T_TBF_BCK_REL = 3 seconds (MS error) OR the transmission window of the MFS is stalled during

T_TBF_BCK_REL = 3 seconds (radio problem).

� Stagnating window: the RLC counter N_StagnatingWindowDL is incremented when the Same oldest RLC

data block in the transmittion window is not acknowledged by the received bitmap of the last Packet

Downlink Ack/Nack message.

The DL TBF is released because the RLC counter N_Stagnating WindowDL exceeds the system parameter

N_STAGNATING_ WINDOW_DL_LIMIT =8 (MS error).

On a UL TBF:

� radio problem: N3101 or N3103 exceeds the limits (48 and 1) or too low TX efficiency (<10%).

� Blocking situation: Reception of N_UL_Dummy_Limit = 15 dummy UL RLC blocks (MS error or radio

problem) OR no reception of the Packet Control Ack at the end of the Uplink TBF during T_TBF_BCK_REL = 3

seconds (MS error).

� Stagnating window: the RLC counter N_StagnatingWindowUL is incremented provided that the receive

window is stalled whenever a UL RLC data block whose BSN is different from the receive window state

variable V(Q) and is received a round trip delay after the previous sending of a Packet Uplink Ack/Nack

message.

The UL TBF is released because the RLC counter N_StagnatingWindowUL exceeds the system parameter

N_STAGNATING_WINDOW_UL_LIMIT = 8 (MS error or radio problem).






1 � 3 � 116

� DL and UL TBF release: TBF radio drops


QoS Indicators, TBF Abnormal Release [cont.] B10

P302c_1Number of times a UL TBF is released because of a radio failure. Considered radio failure is:- a radio link lost due to N3101 (N3101 exceeds its limit)

NB_UL_TBF_REL_DUE_TO_RADIO_FAILURE_N3101

P302c_2Number of times a UL TBF is released because of a radio failure. Considered radio failure is:- a radio link lost due to N3103 (N3103 exceeds its limit)

NB_UL_TBF_REL_DUE_TO_RADIO_FAILURE_N3103

P302c_3Number of times a UL TBF is released because of a radio failure. Considered radio failure is:- too low TX efficiency.

NB_UL_TBF_REL_DUE_TO_RADIO_FAILURE_TX_EFF

P302c_4

Number of times a UL TBF is released because of a radio failure. Considered radio failure is:- a radio link lost due to N_POLLING_EUTM (N_POLLING_EUTM exceeds its limit)

NB_UL_TBF_REL_DUE_TO_RADIO_FAILURE_N_POLLING_EUTM

P302b_2Number of times a DL TBF is released because of a radio failure. Considered radio failure is:- too low TX efficiency.

NB_DL_TBF_REL_DUE_TO_RADIO_FAILURE_TX_EFF

P302b_1Number of times a DL TBF is released because of a radio failure. Considered radio failure is:- a radio link lost due to N3105 (N3105 exceeds its limit)

NB_DL_TBF_REL_DUE_TO_RADIO_FAILURE_N3105







1 � 3 � 117

Downlink Data Transfer

050

100150200250300350400450500

14/0

8/200

3

16/08/2

003

18/0

8/200

3

20/08/2

003

22/0

8/200

3

24/0

8/200

3

26/08/2

003

28/0

8/200

3

30/0

8/200

3

01/0

9/200

3

03/0

9/200

3

05/0

9/200

3

07/0

9/200

3

09/0

9/200

3

11/0

9/200

3

13/0

9/200

3

0

20

40

60

80

100

120

BSS pb

Gb drop

BlockingdropStagnat drop

Radio pb

% AccRelease% NormRelease

Uplink Data Transfer

0

50

100

150

200

250

300

350

14/0

8/200

3

16/0

8/200

3

18/0

8/200

3

20/0

8/200

3

22/08/2

003

24/0

8/200

3

26/0

8/200

3

28/0

8/200

3

30/0

8/200

3

01/0

9/200

3

03/0

9/200

3

05/0

9/200

3

07/0

9/200

3

09/09/2

003

11/0

9/200

3

13/0

9/200

3

0

20

40

60

80

100

120

BSS pb

Gb drop

Blocking pb

Stagnat pb

Radio pb

% AccRelease% NormRelease


QoS Indicators, TBF Drops, Graph

The causes of drop during a DL data transfer are mainly radio problems.

The causes of drop during a UL data transfer are radio problems + blocking problems (MS error suspected

because seen on every network).






1 � 3 � 118

� Thresholds

� When the Delayed DL TBF release is not activated and CS2 is not used at the beginning of the TBF:� the UL/DL TBF normal release rate is seen as good above 98%

� When the Delayed DL TBF release is activated or CS2 is used at the beginning of the TBF (default value):� The threshold of the DL TBF normal release rate should be lower


QoS Indicators, TBF Drops, Graph [cont.]

The QoS threshold values assume that the MS mobility (reselection) is negligible.

The typical values for a DL TBF normal release rate:

� When a Delayed DL TBF release is activated: 95%

� When a Delayed DL TBF release is activated and CS2 is activated at the beginning of the TBF: 90%

� The longer the TBF duration the higher the probability to drop.

� There is a high probability to be in CS2 during the Delayed phase.

The typical values for UL TBF normal release rate:

� When CS2 is activated at the beginning of the TBF: 98.3%, 98.9%

� A UL TBF is often short.

� The Coding Scheme is always CS1 during the MS contention resolution (based on TLLI) for security.

RLS procedures are active during the delayed phase.






1 � 3 � 119

4 MS Sessions / Transfers






1 � 3 � 120


Definitions

� Transfer

� Exchange of RLC data blocks between the MS and the BSS

� The bias of a transfer is the main direction of the transfer in terms of number of bytes transferred

� Session

� Uninterrupted sequence of data transfers between the MS and the BSS

� begin: a UL or DL TBF is established for an MS in PIM

� on-going: at least one TBF is established

� end: the last on-going UL or DL TBF is released

During a transfer the MS and the BSS exchange some RLC blocks either in UL only or in DL only or in the two

directions.

A transfer can correspond to:

� One complete TBF

� Part of one TBF

� Part of two TBFs

� One complete TBF together with part of one TBF in the other direction

The first transfer of a session corresponds to the start of the first TBF of the session.

Then the Alcatel BSS regularly determines the bias of the on-going transfer of the MS.

� The number of octets transferred in both directions is counted and averaged for that purpose.

� If disabled, the bias remains the one chosen at the establishment of the TBF.

� By default, a transfer is deemed downlink biased (at first establishment), except in case the MS context is

created upon receipt of a 2-phase access UL establishment request, in which case the bias is set to uplink.

As soon as the bias of the transfer is about to change the ongoing transfer terminates and a new transfer

begins.

A session never ends when a DL TBF is released but at the expiry of timer T3192, in case there is no UL TBF

on-going in the meantime.






1 � 3 � 121


Example

� A session made up of:

� 5 TBFs (1 DL, 4 UL)� 3 transfers (1 DL biased, 2 UL biased)

UL TBFs

DL TBFs active delayed

Bias UL DL UL

change of bias change of bias

Xfer 1 Xfer 2 Xfer 3

Session

Transfers

Transfer 1 and 3 are UL biased.

Transfer 2 is DL biased.






1 � 3 � 122


Exercise

� Exercise 1: Using the trace 2bis, find bias direction along transfer

Time allowed:

30 minutes

B10






1 � 3 � 123

� Sessions and transfers

Session

Transfer

Number of sessions

Average duration

Cumulated time an MS is engaged in DL/UL biased transfers

% of time DL/UL TBF are granted the maximum nb of

PDCHs they support and the corresponding MSs are

engaged in DL/UL biased transfers

Average number of DL/UL TBF per session


QoS Indicators






1 � 3 � 124

� MS Sessions


QoS indicators, MS Sessions

( (P30a + P30b + P30c + P508)

/ (P413))

Average number of

UL TBF established

per session

( (P90a + P90b + P90c + P90d

+ P90e + P90f + P506) /

(P413))

Average number of DL

TBF established per

session

UplinkDownlink

(P419+ P420) / P413Average duration of a session

P413Number of GPRS and EGPRS sessions

GPRS/EGPRS sessions






1 � 3 � 125

� MS Transfers


QoS Indicators, MS Transfers

P410 / P412

% of time UL TBF are granted the

maximum number of PDCH they

support and the corresponding MS are

engaged in UL biased transfers

P409 / P411

% of time DL TBF are granted the

maximum number of PDCH they


engaged in DL biased transfers

P410

Cumulative time UL TBF are granted

the maximum number of PDCH they


engaged in UL biased transfers

P409

Cumulative time DL TBF are granted

the maximum number of PDCH they


engaged in DL biased transfers

P412

Cumulative time MS are served by UL

TBF and engaged in UL biased

transfers

P411Cumulative time MS are served by DL

TBF and engaged in DL biased transfers

P420 / (P419 + P420)Uplink biaised ratioP419 / (P419 + P420)Donwlink biaised ratio

P420Cumulative time MS are engaged in UL

biased transfersP419

Cumulative time MS are engaged in DL

biased transfers

UplinkDownlink

Bias of the ongoing transfers

Determination of the Bias:

� Uplink: when a first UL TBF is established using the 2-phase access on a CCCH or PCCCH

� Downlink: in any other case






1 � 3 � 126


QoS Indicators, MS Transfers, Example

UL TBFs

DL TBFs

Bias UL DL UL

change of bias change of bias

Xfer 1 Xfer 2 Xfer 3

Session

Transfers

active delayed

3TS 4TS 4TS 2TS 2TS

2TS1TS2TS 1TS 1TS

PDCH preemptionof 2 TS

2TS

P411

P409

timeP419

P420P412P410

DL

UL

Transfer 1 and 3 are UL biased.

Transfer 2 is DL biased.






1 � 3 � 127

DL session

0

50000

100000

150000

200000

250000

14/08

/2003

16/08

/2003

18/08

/2003

20/08

/2003

22/08

/2003

24/08

/2003

26/08

/2003

28/08

/2003

30/08

/2003

01/09

/2003

03/09

/2003

05/09

/2003

07/09

/2003

09/09

/2003

11/09

/2003

13/09

/2003

86889092949698100102

Time Opt alloc

DL Time bias

Time bias

%Time OptAlloc

UL session

0

1000

2000

3000

4000

5000

6000

14/08

/2003

16/08

/2003

18/08

/2003

20/08

/2003

22/08

/2003

24/08

/2003

26/08

/2003

28/08

/2003

30/08

/2003

01/09

/2003

03/09

/2003

05/09

/2003

07/09

/2003

09/09

/2003

11/09

/2003

13/09

/2003

0

20

40

60

80

100

120

Time Opt alloc

UL Time bias

Time bias

%Time OptAlloc


QoS Indicators, Graph

The typical values of the DL TBF optimal allocation time rate (without resource re-allocation):

� Without congestion (GSM+GPRS): 93%, 94%, 95%, 96%

� With congestion: 79.5%

The UL TBF optimal allocation time rate can be biased, due to the restriction on P29.

However, on small area, it can give typical values:

� Without congestion (GSM+GPRS): 68.5%, 76%, 92%, 98%

� With congestion: 98%

These typical values are highly dependent on the penetration rate of class 9 or class 10 mobiles (mobiles

able to use 2 TSs on the UL path).






1 � 3 � 128

5 Resource Usage






1 � 3 � 129

� The BSS uses several resources to transfer data between the MS and the GPRS core network

� Air interface resources

� Physical channels: MPDCH, SPDCH

� logical channels:

� control channels� without MPDCH: BCCH, AGCH, PCH, RACH

� with MPDCH: PBCCH, PAGCH, PPCH, PRACH

� traffic channels: PDTCH

� associated signaling channel: PACCH

5 Resource Usage

BSS Resources, Air Interface






1 � 3 � 130

� The GPU resource (BSS internal resource)

� The GPRS traffic of a group of cells is handled by the GPU function mapped on a hardware component: the GPU board

5 Resource Usage

BSS Resources, GPU

G

P

U

8 PCM 8 PCM

Ater Gb

SGSNBSC

in MFS equipmentUL

Each GPU handles the GPRS traffic of cells belonging to the same BSS.

There is a maximum number of GPUs to monitor the traffic of one BSS.

Up to 240 PDCHs can be active at the same time on the same GPU.






1 � 3 � 131

5 Resource Usage

BSS Resources, Abis/Ater Interface

TRX 3

TRX 2

TRX 1

� The Abis resources can be seen as a pool of Abis nibbles shareable between all TREs of a given sector (basic Abis nibbles) or all the TREsof a given BTS (extra and bonus Abis nibbles).

� An M-EGCH organizes the transmission resources (pool of Abis nibbles and Ater nibbles) given to a TRX for its PS traffic.

Abis Ater

M-EGCH 3

M-EGCH 2

M-EGCH 1

Scheme Modulation Raw data rate(in kbit/s)

Number ofGCH

CS-1 GMSK 8 1CS-2 GMSK 12 1CS-3 GMSK 14.4 2CS-4 GMSK 20 2

MCS-1 GMSK 8.8 1MCS-2 GMSK 11.2 1

14.8 2MCS-3 GMSK 13.6 2MCS-4 GMSK 17.6 2MCS-5 8-PSK 22.4 2

29.6 3MCS-6 8-PSK 27.2 3MCS-7 8-PSK 44.8 4MCS-8 8-PSK 54.4 4MCS-9 8-PSK 59.2 5

For EGPRS traffic, an EGCH physical channel is allocated per PDCH which is a set of n GCHs, n depending on

the maximum CS or MCS number that can be used on the PDCH:






1 � 3 � 132

� Gb interface resource

� A BVC is the logical identifier to which is linked the traffic of a cell carried over the Gb interface

� The traffic of all the BVCs controlled by the same GPU is multiplexed and carried by the 64 Kbit/s PCM time slots on the Gb interface

5 Resource Usage

BSS Resources, Gb Interface

GPU

8 PCM

GbBVCI=2BVCI=2

BVCI=1BVCI=1

BVCI=3BVCI=3BSC1

BVCI=5BVCI=5

BVCI=6BVCI=6

BVCI=4BVCI=4 BSC2

SGSN






1 � 3 � 133

� BSC – MFS messages

5 Resource Usage

BSS Resources, BSC - MFS Exchanges

RR Allocation Indication

RR Usage Indication

MFS

BSC

Thanks to the “Autonomous Packet Resource Allocation” feature, the MFS no longer needs to request

the BSC for additional SPDCHs (as in B8); as all the usable PS-capable radio timeslots are explicitly

allocated to the MFS through the RR Allocation Indication message. However, the RRM-PRH entity has

the responsibility for handling the RR Allocation Indication and RR Usage Indication messages,

especially for the following tasks:

� interpretation of the SPDCHs_Allocation bitmap contained in the RR Allocation Indication message

(in particular, if a SPDCH is removed in the bitmap, then a preemption process may have to be

started, cf. section �4 for more details),

� building and sending of the SPDCHs_Confirmation bitmap, the SPDCHs_Usage bitmap, the

SPDCHs_RadioUsage bitmap and the DTM_TCH bitmap, through the RR Usage Indication message.






1 � 3 � 134

5 Resource Usage

BSS Resources, BSC - MFS Exchanges, GTTP UL B10

BSCGP DTM GPRS Info UL [1st segment](3)

MS BSC MFS

Dedicated mode (SDCCH/TCH) (1)

P513

GPRS Information [UL LLC PDU] (2)

BSCGP DTM GPRS Info UL [2nd segment](3)

UL LLC PDUs (4)

[main DCCH]

1. The MS is in dedicated mode and required to send GPRS signaling information to the SGSN (for

instance to perform a cell update).

2. Provided that the GPRS signaling information can be encoded in the MAX_LAPDm LAPDm frames,

the MS sends on the main DCCH the GPRS Information message to the BTS. The BTS assembles the

LAPDm frames received in the GPRS Information message and forwards it to the BSC on RSL.

3. The BSC forwards the GPRS information to the MFS through a BSCGP DTM GPRS Information UL

message. This message contains the 44.060 GPRS Information and the references of the MS (i.e., the

IMSI and the BSC reference).

4. The MFS decodes the 44.060 GPRS Information message and builds accordingly the UL LLC PDU.

Then, the MFS sends the UL LLC PDU towards the SGSN.

P513: Number of bytes received from the MS with the GTTP protocol.

This counter is incremented by the number of bytes of the UL LLC PDU carried in the BSCGP DTM

GPRS information messages received in MFS.






1 � 3 � 135

5 Resource Usage

BSS Resources, BSC - MFS Exchanges, GTTP DL B10

BSCGP DTM GPRS Info DL (3)

MS BSC MFS

Dedicated mode (SDCCH/TCH) (1)

P514

GPRS Information [DL LLC PDU] (4)

BSCGP DTM GPRS Info DL ACK (4)

DL LLC PDUs (2)

[main DCCH] T_WAIT_DTM

1. The MS is DTM capable and in dedicated mode.

2. The MFS receives a DL LLC PDU with the T-bit set in the QoS Profile IE (for instance if the MS is

performing a RA update to send the RA Update Accept message).

3. As the MFS is aware that the MS is in dedicated mode, it checks whether the DL LLC PDUs can be

encoded in the MAX_LAPDm LAPDm frames available. If this is the case, the MFS builds the 44.060

GPRS Information message containing the DL LLC PDU and sends it to the BSC in the BSCGP DTM GPRS

Information DL message. In addition, the BSCGP DTM GPRS Information message contains the

references of the MS (i.e., the IMSI and the BSC reference) and possibly the SDCCH/TCH identity of

the CS connection.

4. The BSC forwards the message to the BTS on RSL. Then, the BTS possibly segments the message

and sends it to the MS on the main DCCH. The BSC acknowledges to the MFS the sending of DL LLC

PDU through the message DTM GPRS Information DL ACK.

P514: Number of bytes sent to the MS with the GTTP protocol.

This counter is incremented by the number of bytes of the DL LLC PDU carried in the BSCGP DTM

GPRS information messages sent by MFS.

Note: Possible repetitions of the messages are not taken into account i.e only the DL_LLC_PDU

acknowledged by BSCGP DTM GPRS information ack message are take into account.






1 � 3 � 136

BTS BSC MFS

Selection of the Ater and Abis nibbles (1) (2)

Transmission-Allocation-Request (Ater nibble ids,

BSC Abis nibble ids, MFS connection references) (6)

RSL-Allocate-Abis-Nibbles (All the BTS Abis nibble ids) (4)

Abis nibble allocation to the TRE (5)

Ater to Abis nibble switching (7)

Transmission-Allocation-Confirm (Ater and BSC Abis nibble ids,

MFS and BSC connection references) (8)

Activate (TRE-Id) (10)

As many as the number of new GCHs in the M-

EGCH link

Activate-Ack (11)

The established GCHs can carry PS traffic

64K Ater TS cross-connection to DSP (9)

Abis-Nibbles-Allocation (All the BTS Abis nibble ids) (3)

Those two messages are sent in sequence

by the MFS

5 Resource Usage

BSS Resources, Scenario for GCH Establishment

This GCH establishment scenario is valid if there are free ABIS and Ater resources (nibbles).






1 � 3 � 137

5 Resource Usage

BSS Resources, Scenario for GCH Release

MFS BSC BTS

Release (1)

As many as the number of GCHs to remove from the M-

EGCH link Release-Ack (2)

Abis nibble deallocation from the TRE (5)

Transmission-Deallocation-Command (BSC connection references) (6)

Transmission-Deallocation-Complete

(Ater nibble ids, MFS connection references) (8) , )

64K Ater TS decross-connection from DSP (9)

Release of the Ater and Abis nibbles (10) (11)

RSL-Allocate-Abis-Nibbles (All the remaining BTS Abis nibble ids) (4)

Abis-Nibbles-Allocation (All the remaining BTS Abis nibble ids) (3)

Those two messages are sent in sequence

by the MFS

Ater to Abis nibble deswitching (7)

This GCH establishment scenario is valid if there are free ABIS and Ater resources (nibbles).






1 � 3 � 138

5 Resource Usage

Exercise

� Exercise 1: using trace 1 , identify the different messages for Abis and Ater resource allocation.

� Exercise 2 : using same trace find different messages for the deallocation of these resources

Time allowed:

10 minutes






1 � 3 � 139

� GPRS radio resources: PDCH

PDCH usage

Average, max, min number and reduction rate

of MAX_SPDCH_LIMIT

Cumulated time PDCHs:

- use at least one DL/UL TBF

- carry GMM traffic

PDCH dynamic establishment success rate

Soft preemption

5 Resource Usage

QoS Indicators, PDCH

Smooth PDCH traffic adaptation






1 � 3 � 140

� GPRS radio resources PDCH: MAX_SPDCH_LIMIT

5 Resource Usage

QoS Indicators, MAX_SPDCH_LIMIT Follow-up

INDICATOR MAX_SPDCH_LIMIT MIN VALUE

DEFINITION Minimum value of allocated SPDCH in the whole granularity period.

FORMULA Σ CELL (P416bis)

INDICATOR MAX_SPDCH_LIMIT MAX VALUE

DEFINITION Maximum value of allocated SPDCH in the whole granularity period.

FORMULA Σ CELL (P415bis)

INDICATOR MAX_SPDCH_LIMIT AVERAGE VALUE

DEFINITION Average value of allocated SPDCH over the observation period.

FORMULA Σ CELL (P414bis) / (PERIOD)

INDICATOR MAX_SPDCH_LIMIT REDUCTION RATE

DEFINITION Reduction rate of allocated SPDCH value integrated over the granularity period.

FORMULA Σ CELL ((P415bis*GP) – P414bis) / (P415bis*GP))






1 � 3 � 141

5 Resource Usage

QoS Indicators, PDCH Usage

Cumulated time during which an UL TBF uses one PDCH, for all PDCHs of the TBF, and for all TBFs of the cell (in GPRS or EGPRS mode).

CUMULATED_TIME_PDCH_UL_TBF_CELLP451a

Cumulated time during which an DL TBF uses one PDCH, for all PDCHs of the TBF, and for all TBFs of the cell (in GPRS or EGPRS mode).

CUMULATED_TIME_PDCH_DL_TBF_CELLP451b

Cumulated time during which a DL TBF established for GMM signalling purposes uses a PDCH (in GPRS or EGPRS mode), for all TBFs of the cell.

CUMULATED_TIME_PDCH_DL_TBF_GMM_SIG_CELLP452

Cumulated time during which a PDCH is used by at least one DL TBF (in GPRS or EGPRS mode), cumulated over all the PDCHs of the cell.

CUMULATED_TIME_PDCH_USED_DL_CELLP38e

Cumulated time during which a PDCH is used by at least one UL TBF (in GPRS or EGPRS mode), cumulated over all the PDCHs of the cell.

CUMULATED_TIME_PDCH_USED_UL_CELLP38f

DefinitionNameCounter number






1 � 3 � 142

5 Resource Usage

QoS Indicators, PDCH Usage

Minimum number of used slave PDCHs in the .

MIN_NB_USED_SPDCH_CELLP496

Maximum number of used slave PDCHs in the cell.MAX_NB_USED_SPDCH_CELLP495

Soft pre-emption

Number of PDCH released after having been marked by the soft pre-emption procedure

NB_PREEMPTED_PDCHP417

Average number of UL+DL TBF candidates to a T1 reallocation per PDCH released after having been marked

(P403a + P404a) / P417

DefinitionNameformula






1 � 3 � 143

� GPRS radio resources: MPDCH

MPDCH usage

MPDCH signaling traffic

MPDCH resource allocation is static ⇒ no indicators

PPCH

PRACH

PACCH

PAGCH

5 Resource Usage

QoS Indicators, MPDCH






1 � 3 � 144

� GPRS radio resources: MPDCH signaling

MPDCH signalling trafficDedicated PPCH signalling load on all the existing MPDCH P61Number of PACKET PAGING REQUEST for PS paging sentto the MS on PPCH

P61a

Number of PACKET PAGING REQUEST for CS paging sentto the MS on PPCH

P61b

Number of Packet DL assignment messages on PPCH P61 - 0.5*P61a - 0.5*P61bOccupancy rate of PS paging messages on PPCH load 0.5 * P61a / P61

Occupancy rate of Packet DL assignment messages on PPCH (P61 - 0.5*P61a - 0.5*P61b) / P61

PRACH signalling load on all the existing MPDCH P399

PRACH signalling load due to NC2 feature P438d% PRACH load induced by NC2 feature (P438d / P399) * 100Dedicated PAGCH signalling load on all the existing MPDCH P400UL PACCH signalling load on all the existing MPDCH P401

5 Resource Usage

QoS Indicators, MPDCH Signaling

The Factor of 0.5 comes from the fact that a PACKET PAGING REQUEST can contain 2 paging messages (like

in GSM between Paging Commands and Paging Requests).






1 � 3 � 145

� GPRS radio resources: CCCH

CCCH load RACH

PCH: PS paging, CS paging, Immediate assignment

AGCH

5 Resource Usage

QoS Indicators, CCCH






1 � 3 � 146

� GPRS radio resources: CCCH load

CCCH loadPaging usage rate due to GPRS P53a / MC8APCH use due to GPRS Immediat Assignment P53cRatio PS/CS paging through SGSN P53a / (P53a+P53b)RACH usage rate due to GPRS P62c / MC8CAGCH usage rate due to GPRS (P49 + P27) / (MC8B + P49 + P27)

5 Resource Usage

QoS Indicators, CCCH Load

P53a = Number of (BSCGP) PAGING REQUEST for PS paging sent to the MS (through the BSC which manages

the PCH resource). (used for instance for an MT picture transfer MMS service).

P53b = Number of (BSCGP) PAGING REQUEST for CS paging sent to the MS (through the BSC which manages

the PCH resource) -> Need of the Gs interface.

P53c = Number of (BSCGP) IMMEDIATE ASSIGNMENT sent to the MS (through the BSC which manages the PCH

resource) for a DL TBF establishment when the MS is in DRX mode.

GSM Paging Command (one per Mobile) or GPRS (BSCGP) PAGING REQUEST are merged into PAGING REQUEST

on the radio layer.






1 � 3 � 147

GPRS/GSM AGCH breakdown

050000

100000150000200000250000300000350000400000450000

14/08

/200

3

16/08

/200

3

18/08

/200

3

20/08

/200

3

22/08

/200

3

24/08

/200

3

26/08

/200

3

28/08

/200

3

30/08

/200

3

01/09

/200

3

03/09

/200

3

05/09

/200

3

07/09

/200

3

09/09

/200

3

11/09

/200

3

13/09

/200

3

00.511.522.533.544.5

PS AGCH

Tot AGCH

% PS AGCH

GPRS/GSM RACH breakdown

050000

100000150000200000250000300000350000400000450000

14/08

/200

3

16/08

/200

3

18/08

/200

3

20/08

/200

3

22/08

/200

3

24/08

/200

3

26/08

/200

3

28/08

/200

3

30/08

/200

3

01/09

/200

3

03/09

/200

3

05/09

/200

3

07/09

/200

3

09/09

/200

3

11/09

/200

3

13/09

/200

3

00.511.522.533.54

Tot RACH

% PS RACH

GPRS/GSM PCH breakdown

02000000400000060000008000000

100000001200000014000000160000001800000020000000

14/08

/200

3

16/08

/200

3

18/08

/200

3

20/08

/200

3

22/08

/200

3

24/08

/200

3

26/08

/200

3

28/08

/200

3

30/08

/200

3

01/09

/200

3

03/09

/200

3

05/09

/200

3

07/09

/200

3

09/09

/200

3

11/09

/200

3

13/09

/200

3

00.10.20.30.40.50.60.70.80.91

CS PAging

PS Imm. As

PS PAging

%io PS Pag

CS AGCH

5 Resource Usage

QoS Indicators, CCCH, Graph






1 � 3 � 148

� GPRS radio resources: Abis nibble

Abis nibble counters

5 Resource Usage

QoS Indicators, Abis Nibble

Number of free nibbles:

- Minimum of free extra or bonus Abis nibble

Number of used nibble:

- Maximum number extra or bonus used nibbles

Cumulated Time during which there are free Abis nibbles






1 � 3 � 149

Abis interface - Abis nibble usage Cumulative time (in seconds), per BTS

,during which there are free extra and bonus Abis nibbles available.

P472

Cumulated time during which extra and bonus Abis nibbles are used in the cell, cumulated over all extra and bonus Abis

nibbles.

P466

Minimum number of free extra and bonus Abis nibbles.

P484

Maximum number of extra and bonus Abis nibbles currently used in the cell (by a GCH

channel)

P465

� GPRS radio resources: Abis nibble usage

5 Resource Usage

QoS Indicators, Abis Nibble

Free Extra and bonus nibbles are given per BTS.

Free extra and bonus nibbles are extra and bonus nibbles not currently used in a GCH.






1 � 3 � 150

� GPRS radio resources: GPU

GPU counters Overall traffic

MS capabilities breakdown

MS multislot class breakdown

5 Resource Usage

QoS Indicators, GPU B10

modified B10

Processing limitation, GCH interface

new B10






1 � 3 � 151

GPU traffic Number of LLC PDU transferred (UL+ DL) P104 Number of UL+DL TBF establishment requests per GPU P107 Number of UL+DL TBF establishment successes per GPU P106 (UL+DL) TBF success rate per GPU (P106 / P107) * 100 Number of PS PAGING request per GPU P391a Number of CS PAGING request per GPU P391b

MS capabilities Number of MS contexts created for Releases 1997 or 1998 mobile stations. P450a Number of MS contexts created for non-EGPRS capable Release 1999 onwards mobile stations

P450b

Number of MS contexts created for EGPRS capable Release 1999 onwards mobile stations.

P450c

Number of MS contexts created P450d Number of MS contexts created for MS supporting the Geran feature package 1

P450e

Number of MS context created for DTM capable mobiles stations. P500 Number of EDA-capable GPRS and EGPRS MS contexts. P594 Ratio of MS contexts created for Releases 1997 or 1998 mobile stations. P450a / ( P450a+P450b+P450c) Ratio of MS contexts created for non-EGPRS capable Release 1999 onwards mobile stations

P450b / ( P450a+P450b+P450c)

Ratio of MS contexts created for EGPRS capable Release 1999 onwards mobile stations.

P450c / ( P450a+P450b+P450c)

� GPRS radio resources: GPU usage and MS capabilities

5 Resource Usage

QoS Indicators, GPU Usage B10

new B10

P450d is incremented the first time the MS Radio Access Capability is received for a given MS context.

Note: This counter is incremented whatever the MS release or feature supported by the MS.

A mobile station is assumed to be Rel-4-compliant if it supports the GERAN Feature Package 1 (theoretically

it is not possible to precisely identify a Rel-4-compliant mobile station). Rel-4-compliant if it its GERAN

Feature Package 1 bit is set to 1.






1 � 3 � 152

� GPRS radio resources: MS multislot class

5 Resource Usage

QoS Indicators, GPU Usage [cont.] B10

P530a_3Number of MS contexts created for MS whose multislot class belongs to the set of multislot classes of type 3X .

NB_MS_MULTISLOT_CLASS_3X

P530a_4Number of MS contexts created for MS whose multislot class belongs to the set of multislot classes of type 4X .

NB_MS_MULTISLOT_CLASS_4X

P530a_2Number of MS contexts created for MS whose multislot class belongs to the set of multislot classes 11 to 12.

NB_MS_MULTISLOT_CLASS_11_TO_12

P530a_1Number of MS contexts created for MS whose multislot class belongs to the set of multislot classes 0 to 10.

NB_MS_MULTISLOT_CLASS_0_TO_10







1 � 3 � 153

� GPRS radio resources: GPU load: DSP and CPU

5 Resource Usage

QoS Indicators, GPU Load

P202This counter cumulates the time during which at least a DSP is in CPU

overload state

P201This counter cumulates the time during which at least a DSP is in CPU

load state

P77aMaximum PMU CPU power budget of the GPU

P76aAverage PMU CPU power budget of the GPU

P402 / GPPercentage of time during which the GPU stays in the PMU CPU

overload state due to PMU CPU power limitations.

P402Cumulated time during which the GPU stays in the PMU CPU overload

state due to PMU CPU power limitations.

P384 / GPPercentage of time during which the DSP is in congestion

P384DSP congestion duration (in seconds).

GPU load

PMU = Packet Management Unit, is responsible for the following tasks:

� RRM (Radio and Resource Management): for TBF, PDCH and MPDCH allocation/de-allocation, radio

resource re-allocation of existing TBFs, PS paging, PDU queuing and Packet System Information

� BSCGP stack management (MFS-BSC interface)

� Gb stack management (MFS-SGSN interface)

The PMU functions are supported by the PPC board (Power PC).

The DSP board supports the Packet Transfer Unit (PTU) functions:

� RLC layer management

� MAC layer management

� L2EGCH layer management

� L1EGCH layer management






1 � 3 � 154

� GPRS radio resources: GCH usage

GCH counters Cumulated time:

- GCHs are in excess in a cell

- GCHs are in deficit in a cell

- GCH is busy in a cell

- GPU is in Ater congestion

- GPU is in « high » Ater usage state

5 Resource Usage

QoS Indicators, GCH

Number of GCHs:

- max number of GCHs busy per GPU

- max number of GCHs busy per cell

- Min number of GCHs busy per GPU

- max number of GCHs in deficit cell

.






1 � 3 � 155

� GPRS radio resources: GCH load in time

5 Resource Usage

QoS Indicators, GCH Load

P383b / GP% of time the GPU is in “high” Ater usage state

P383bTime (cumulated over a granularity period) during which the GPU remains in "high"

Ater usage

P383a / GP% of time the GPU is in Ater congestion state

P383aAtermux congestion duration (in seconds) due to a lack of GCH transmission

resources on the Atermux interface

P470Cumulative time (in seconds), per cell , during which there is a deficit of GCH

resources (16k channel).

P471Cumulative time (in seconds), per cell ,during which there is a excess of GCH

resources (16k channel).

P101Cumulative time (in seconds) during which a GCH resource (16k channel) is

available in the GPU

P100cCumulative time (in seconds) during which a GCH (16k channel) is busy in the cell.

The counter is integrated over all the GCH available in the cell.

Ater interface - GCH






1 � 3 � 156

� GPRS radio resources: GCH load in number per cell and per GPU

5 Resource Usage

QoS Indicators, GCH Load

P100dMaximum number of busy GCH (16k channel) in the cell.

P100eMinimum number of busy GCH (16k channel) in the GPU.

P100fMaximum number of busy GCH (16k channel) in the GPU.

P469Maximum number of GCH in deficit reached in the cell.

Ater interface - GCH

For a DRFU BTS, a GCH is said busy when it is connected to a given PDCH.

For an Evolium BTS, a GCH is said busy when it is connected to a given TRX (as part as an M-EGCH).






1 � 3 � 157

� GPRS radio resources: Ater nibble usage

Ater nibble counters

Number of free nibbles:

- Minimum of Ater

- Minimum of free extra or bonus Ater nibbles

Number of used Nibble:

- Maximum number extra or bonus used nibbles

5 Resource Usage

QoS Indicators, Ater Nibble

Cumulated Time during which there are free Ater nibbles

given per GPU






1 � 3 � 158

� GPRS radio resources: Ater nibble usage

5 Resource Usage

QoS Indicators, Ater Nibble

P474

P465

P484

P486

Cumulative time (in seconds), per GPU ,during which there are free Ater

nibbles.

A free Ater nibble is an Ater nibble not currently used by a GCH.

Maximum number of extra and bonus Abis nibbles currently used in the cell (by

a GCH channel).

Minimum number of free extra and bonus Abis nibbles.

Free extra and bonus nibbles are extra and bonus nibbles not currently used in

a GCH.

Minimum number of free Ater nibbles.

Ater interface – Ater nibbles usage






1 � 3 � 159

� Ater resources capacity must be increased for EDGE

� Example for one GPU board with 2 AterMux for GPRS

5 Resource Usage

QoS Indicators, Impact of EDGE Activation

0

50

100

150

200

250

300

350

400

450

500

0,0%

10,0%

20,0%

30,0%

40,0%

50,0%

60,0%

70,0%

Total_Ater_GIC_available Ater_Cong_Rate

232 GCHs

348 GCHs

464 GCHs

2 AterMux are not enoughfor EDGE traffic

4 AterMux are neededto avoid Ater congestion

Ater_Cong_Rate = P383a / GP = Percentage of time all GCHs are busy in the GPU

Total_Ater_GIC_available = Number of GCHs available for traffic is not a counter but a configuration

variable depending on the number of AterMux connected to the GPU and which available for traffic






1 � 3 � 160

� DSP congestion can occur in the GPU even if enough Ater resources are available

� Same GPU: EDGE is activated cell by cell

5 Resource Usage

QoS Indicators, Impact of EDGE Activation [cont.]

0

50

100

150

200

250

300

350

400

450

500

0,0%

0,5%

1,0%

1,5%

2,0%

2,5%

3,0%

Total_Ater_GIC_available GPU_Cong_Rate

232 GCHs

348 GCHs

464 GCHs

The more cells are EDGE capable the higher the GPU DSP congestion

GPU_Cong_Rate = (P384/10) / GP = Percentage of time the GPU is in DSP congestion

Total_Ater_GIC_available = Number of GCHs available for traffic is not a counter but a configuration

variable depending on the number of AterMux connected to the GPU and which available for traffic






1 � 3 � 161

5 Resource Usage

QoS Indicators, BVC

� GPRS radio resources: BVC

BVC Number of DL LLC bytes

Number of UL LLC bytes

Received from the SGSN

Discarded due to congestion

Discarded due to a Suspend procedure

Received from the MS

Rerouted

Not rerouted

Well received from the SGSN

BVC availability






1 � 3 � 162

5 Resource Usage

QoS Indicators, BVC, Traffic, Availability

� GPRS radio resources: BVC traffic, BVC availability

P67Time during which the BVC associated to a cell is unavailable for traffic

BVC (cell) unavailability

(P43 - P10 - P96) / P43DL LLC bytes well received rate

P43 - P10 - P96DL LLC bytes well received

P96DL LLC bytes not rerouted

P95Downlink LLC bytes well rerouted

P99 / P43% of DL LLC bytes discarded due to suspend procedure

P99Number of DL LLC bytes discarded due to suspend procedure

P10 / P43DL LLC congestion rate

((P43 - P10) * 8) / (GP * 1000)Average DL useful throughput in kbit/s

P23Number of UL LLC bytes discarded due to congestion at SNS level

P10Number of DL LLC bytes discarded due to congestion

P44dNumber of UL LLC bytes received from MS in EGPRS NACK mode

P43dNumber of DL LLC bytes received by MS in EGPRS NACK mode

P44cNumber of UL LLC bytes received from MS in EGPRS ACK mode

P43cNumber of DL LLC bytes received by MS in EGPRS ACK mode

P44bNumber of UL LLC bytes received from MS in GPRS NACK mode

P43bNumber of DL LLC bytes received by MS in GPRS NACK mode

P44aNumber of UL LLC bytes received from MS in GPRS ACK mode

P43aNumber of DL LLC bytes received by MS in GPRS ACK mode

P44Number of UL LLC bytes received from MSP43Number of DL LLC bytes received from SGSN

UplinkDownlink

BVC (cell) traffic

LLC bytes discarded: relating to the PDU LifeTime expiry or to the GPU buffer congestion (can be linked to

degraded DL Flow Control algorithm).

P99: The introduction of the Suspend-Resume mechanism between the MFS and the SGSN can generate GPRS QoS problems. If the suspend time exceeds the tolerable threshold for the distant server the MS is

connected to, it can generate disconnection from the server. Even though, the disconnection does not

mean that the PDP context is deactivated. It belongs to IP GSS feature (capacity to generate dummy IP

blocks to keep the Gi link alive).

P96 is likely to be sensitive to a lot of reselection problems an MS has to face in the GPRS network (no GPRS

resources available in the selected cell, reselection of an MS in a new cell belonging to a new MFS or a new

SGSN, etc).






1 � 3 � 163

5 Resource Usage

QoS Indicators, PVC and BC Unavailability

� GPRS radio resources: BVC

PVC Time unavailaibility

BC Time unavailaibility






1 � 3 � 164

� GPRS radio resources: PVC, BC unavailability

5 Resource Usage

QoS Indicators, PVC and BC Unavailability

P33/GPPercentage of time during which the BC (Bearer Channel)

is not available on Gb Interface

P34/GPPercentage of time during which the PVC (Permanent

Virtual Connection) is not available on Gb Interface.

Gb interface – PVC, BC






1 � 3 � 165

5 Resource Usage

QoS Indicators, Graph

Details of downlink LLC traffic

0100000020000003000000400000050000006000000700000080000009000000

14/0

8/200

3

16/0

8/200

3

18/0

8/200

3

20/0

8/200

3

22/0

8/200

3

24/0

8/200

3

26/0

8/200

3

28/0

8/200

3

30/0

8/200

3

01/0

9/200

3

03/0

9/200

3

05/0

9/200

3

07/0

9/200

3

09/0

9/200

3

11/0

9/200

3

13/0

9/200

3

98.498.698.89999.299.499.699.8100100.2 Blocked bytes

DiscardedbytesNot rerouted

ReroutedbytesReceivedbytes%Well receiv

Details of uplink LLC traffic

0500000

1000000150000020000002500000300000035000004000000

14/0

8/200

3

16/0

8/200

3

18/0

8/200

3

20/0

8/200

3

22/0

8/200

3

24/0

8/200

3

26/0

8/200

3

28/0

8/200

3

30/0

8/200

3

01/0

9/200

3

03/0

9/200

3

05/0

9/200

3

07/0

9/200

3

09/0

9/200

3

11/0

9/200

3

13/0

9/200

3

UL sent bytes






1 � 3 � 166

6 CS and MCS Adaptation






1 � 3 � 167


Modulations and Data Rates

� Data rate per radio TS (RLC payload)

8PSK modulation to

provide higher data rates

GMSK modulation to

ensure a certain level of

performance in case of

poor radio conditions8.8GMSKMCS-1

11.2GMSKMCS-2

14.8 / 13.6 *GMSKMCS-3

17.6GMSKMCS-4

22.48PSKMCS-5

29.6 / 27.2 *8PSKMCS-6

44.88PSKMCS-7

54.48PSKMCS-8

59.28PSKMCS-9

EGPRS

9.05GMSKCS-1

13.4GMSKCS-2

15.6GMSKCS-3

21.4GMSKCS-4

GPRS

Maximum rate (kbps)

ModulationScheme






1 � 3 � 168


DL CS Adaptation

AV_RXQUAL_LT

AV_SIR

CS-1

CS-2

CS-3CS-4

CS_QUAL_DL_1_2_X_Y+ CS_HST_DL_LT

CS_QUAL_DL_1_2_X_Y

CS_QUAL_DL_2_3_X_Y

C S_QUAL_DL_3_4_X_Y

0

7

0 15CS_SIR_DL_3_4_X_Y CS_SIR_DL_3_4_X_Y +

CS_SIR_HST_DL

CS-1 or CS-2 (hysteresis)

CS-2 or CS-3 (hysteresis)

CS-3 or CS-4

(hysteresis)

CS_QUAL_DL_2_3_X_Y + CS_HST_DL_LT

BLER100% 0%CS_BLER_DL_3_4 CS_BLER_DL_4_3

The change from CS3 to CS4 is not only based on AV_RXQUAL_LT for the two following reasons:

� The RXQUAL range only goes down to 0.2%. However, the change of coding scheme from CS3 to CS4 will

probably have to be done for even lower values. Indeed, when the coding scheme is CS4, in static (AWGN),

a BLER of 0.1 (typical value of the BLER threshold to change from CS3 to CS4) is obtained for a raw BER of

1-(1-0.1)1/456 = 2.10-4. This raw BER would be larger in multipath channels but is likely to remain below

0.2%. This means that CS_QUAL_DL_3_4 should be close to 0 and that a condition based on RXQUAL is not

sufficient to change the coding scheme from CS3 to CS4.

� If the changes from CS3 to CS4 and from CS4 to CS3 are based on different metrics, a Ping-Pong effect can

occur. Indeed, it can happen that the conditions to change from CS3 to CS4 and CS4 to CS3 are

simultaneously true in some situations.

In case a TBF is established on PDCHs of a non-hopping BCCH TRX or on PDCHs using a FHS including the

BCCH frequency a new algorithm is used for adaptation between CS3 and CS4 based on BLER computation

and comparison to threshold. Indeed in these 2 cases most of the MS will not report any C/I measurements

on idle frames.






1 � 3 � 169


UL CS Adaptation

� GPRS CS adaptation in the ULAV_RXQUAL_LT

AV_SIR

CS1

CS2

CS_QUAL_UL_1_2_X_Y + CS_HST_UL_LT

CS_QUAL_UL_1_2_X_Y

CS_QUAL_UL_2_3_X_Y

0

7

0 15

CS1 or CS2 (hysteresis)

CS2 or CS3 (hysteresis)

CS3

CS4

CS3 or CS4 (hysteresis)CS_QUAL_UL_3_4_X_Y



In the up-link, the RXQUAL is available in CS4 and the SIR measurements are not reported by the BTS to the

MFS so far. Therefore, it is possible to use also RXQUAL measurements to change the coding scheme from

CS3 to CS4 or from CS4 to CS3, contrary to the downlink algorithm, for which the SIR is used.






1 � 3 � 170


DL MCS Adaptation

� In RLC acknowledged mode, the MFS applies a given MCS taking into account:

� Current MCS:

� MCS-1 to MCS-4 in GMSK

� MCS-5 to MCS-9 in 8-PSK

� Average Power Decrease: APD set = [0, 1, 3, 4, 5, 6, 8, 10]

� MS OUT OF MEMORY state

� = Off then LA tables with IR are used

� = On then LA tables without IR (Type I ARQ) are used

� In RLC unacknowledged mode, the MFS applies a given MCS taking into account:

� Current MCS:


� MCS-5 to MCS-9 In 8-PSK


� Each combination of these criteria corresponds to a specific LA table

Extract of a table when APD=0dB, Type 1 ARQ, 8PSK table: if MCScurrent belongs to {5,6,7,8,9}

0 1 2 3 4 5 6 7

0 5 5 5 5 1 1 1 1

1 5 5 5 5 1 1 2 2

2 5 5 5 5 1 2 2 2

3 5 5 5 5 2 2 2 3

4 5 5 5 5 5 2 3 3

5 5 5 5 5 5 3 3 3

6 5 5 6 5 5 5 3 3

7 5 5 6 5 5 5 3 3

8 5 5 6 6 5 5 5 4

9 5 6 6 6 5 5 5 5

10 5 6 6 6 6 5 5 5

11 6 6 6 6 6 6 5 5

12 6 6 6 6 6 6 5 5

13 6 6 6 6 6 6 5 5

14 7 6 6 6 6 6 6 6

15 7 6 6 6 6 6 6 6

16 7 7 6 7 6 6 6 6

17 7 7 7 7 7 6 6 6

18 7 7 7 7 7 7 7 7

19 7 7 7 7 7 7 7 7

20 7 7 7 7 7 7 7 7

21 7 7 7 7 7 7 7 7

22 7 8 8 8 8 8 8 8

23 8 8 8 8 8 8 8 8

24 8 8 8 8 8 8 8 8

CV_BEP

ME

AN

_BE

P






1 � 3 � 171


UL MCS Adaptation

� In RLC acknowledged mode, the MFS applies a given MCS taking into account:

� Current MCS:


� MCS-5 to MCS-9 in 8-PSK

� APD of the MS: APD set = [0, 1, 3, 4, 5, 6, 8, 10]

� EN_IR_UL state

� = enable then LA tables with IR are used

� = disable then LA tables without IR (Type I ARQ) are used

� In RLC unacknowledged mode, the MFS applies a given MCS taking into account:

� Current MCS:


� MCS-5 to MCS-9 In 8-PSK


� Each combination of those criteria corresponds to a specific LA table

In the up-link the same tables as in the down-link apply.






1 � 3 � 172


Exercise

� Exercise 1: using trace 20 , find at what time the MCS is changed

Time allowed:

15 minutes






1 � 3 � 173

� CS and MCS adaptation

PDTCH

RLC blocks

PACCH

RLC blocks

Number of useful blocks, retransmitted blocks, lost

bytes for GPRS CS1,2,3,4 for EGPRS MCS1, … , MCS9

Retransmission rate, lost rate

Throughput per cell, per PDCH, per TBF

PDTCH occupancy

Useful CSx and MCSx distribution

PACCH occupancy

GPRS Coding Scheme increase and decrease


QoS Indicators






1 � 3 � 174

� CS and MCS adaptation: RLC statistics in GPRS mode


QoS Indicators, RLC Statistics, GPRS Mode

P336Average TX_EFFICIENCYP335Average TX_EFFICIENCY

(P21a*160+P21b*240+P21c*288+P21d*400)/(P21a*160+P21b*240+P21c*288+P21d*400+P57a*160+P57b*240+P57c*288+P57d*400)

In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in CS-x

(P20a*160+P20b*240+P20c*288+P20d*400)/(P20a*160+P20b*240+P20c*288+P20d*400+P55a*160+P55b*240+P55c*288+P55d*400)

In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in CS-x

(P57x) / (P57a+P57b+P57c+P57d)PDTCH RLC block CSx / (CS1+CS2+CS3+CS4) ratio

P55x / (P55a+P55b+P55c+P55d)PDTCH RLC block CSx / (CS1+CS2+CS3+CS4) ratio

(P21a + P21b + P21c + P21d) / P350bPDTCH RLC block retransmission rate in GPRS ack mode

(P20a + P20b + P20c + P20d) / P350aPDTCH RLC block retransmission rate in GPRS ack mode

CS1+CS2+CS3+CS4 : P72dNumber of lost PDTCH RLC bytes in GPRSnack mode

CS1+CS2+CS3+CS4 : P72cNumber of lost PDTCH RLC bytes in GPRSnack mode

CS1 : P21aCS2 : P21bCS3 : P21cCS4 : P21d

Number of retransmitted PDTCH RLC blocks inGPRS ack mode


Number of retransmitted PDTCH RLC blocks inGPRS ack mode


Number of useful PDTCH RLC blocks acknowledged by the MS in GPRS ack mode


Number of useful PDTCH RLC blocks acknowledged by the MS in GPRS ackmode

UplinkDownlink

RLC statistics

KPI

KPI

KPI

KPI

KPI

KPI

The average TX_EFFICIENCY is equal to:

� Where:

� NB_SENT is the number of transmitted RLC data blocks,

� NB_RECEIVED is the number of correctly received RLC data blocks (i.e., blocks for which a positive acknowledgment is reported),

� ρi is equal to the number of information bits in the i-th correctly received RLC data block divided by the number of bits per RLC data block with GMSK modulation (456 in GPRS). This ratio only depends on the coding scheme used for the i-th correctly received RLC data block and is between 0 and 1 in GPRS. The values of the number of information bits per RLC data block for each coding scheme are defined in 05.03 TS Specification document.

CS1 CS2 CS3 CS4

ρ 0.40 0.59 0.68 0.94

ni is the number of RLC data blocks in the i-th radio block. Therefore, this number is always equal to 1 for GPRS,

It is computed every TX_EFFICIENCY_PERIOD (=200) RLC data blocks.

It is compared to TX_EFFICIENCY_ACK_THR (=10%) or TX_EFFICIENCY_NACK_THR (=15%) to trigger radio drop.

∑

∑

=

==SENTNB

i i

RECEIVEDNB

i i

n

nEFFICIENCYTX _

1

_

1

i

1100_

ρ






1 � 3 � 175


QoS Indicators, RLC Statistics, EGPRS Mode

� CS and MCS adaptation: RLC statistics in EGPRS mode

KPI

KPI

B10

new B10 new B10

p21e/(p21e+((P57e*176+P5

7f*224+P57g*296+P57h*352+

(P57i*448+P57j*592+(P57k*8

96+P57l*1088+P57m*1184)/

2)) / 8))

In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in MCS-x

P20e/(P20e+(P55e*176+P55

f*224+P55g*296+P55h*352+P

55i*448+P55j*592+(P55k*89

6+P55l*1088+P55m*1184)/2

)/ 8))

In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in MCS-x

P57x/(P57e+P57f+P57g+P57

h+P57i+P57j+P57k+P57l+P5

7m)

In RLC ack mode, ratio of useful RLC blocks sent in RLC acknowledged mode on PDTCH and encoded in MCS-x

P55x/(P55e+P55f+P55g+P55

h+P55i+P55j+P55k+P55l+P5

5m)

In RLC ack mode, ratio of useful RLC blocks sent in RLC acknowledged mode on PDTCH and encoded in MCS-x

P73dMCS-x lost bytesP72dMCS-x lost bytes

MCS1 : P21f

MCS2 : P21g

……

……

MCS9 : P21n

Number of useful RLC blocks

retransmitted in RLC

acknowledged mode on PDTCH

and encoded in MCS-1/2/…/9.

MCS1 : P20f

MCS2 : P20g

……

……

MCS9 : P20n

Number of useful RLC blocks

retransmitted in RLC

acknowledged mode on PDTCH

and encoded in MCS-1/2/…/9.

MCS1 : P57e

MCS2 : P57f

.......

.......

MCS9 : P57m

Number of useful RLC blocks sent

in RLC acknowledged mode on

PDTCH encoded in MCS-1/2/…/9.

MCS1 : P55e

MCS2 : P55f

……

……

MCS9 : P55m

Number of useful RLC blocks sent

in RLC acknowledged mode on

PDTCH and encoded in MCS-

1/2/…/9.

UplinkDownlink

RLC statistics

P20e respectively P21e have been removed. In acknowledged mode, number of DL respectively UL RLC data

bytes (except RLC blocks containing LLC Dummy UI Commands only) on PDTCH encoded in MCS-x (with x = 1

to 9) retransmitted due to unacknowledgement of the MS respectively MFS.






1 � 3 � 176


QoS Indicators, CS Adaptation

� CS and MCS adaptation: CS adaptation

P352b / (P30a + P30b +

P30c)

Average number of CS

adaptions decrease per

TBF

P351b/ (P90a + P90b +

P90c + P90d + P90e +

P90f)


adaptions decrease per

TBF

P352a / (P30a + P30b +

P30c)


increase per TBF

P351a / (P90a + P90b +

P90c + P90d + P90e +

P90f)


increase per TBF

P352bNumber of CS adaptions

from a given coding

scheme to a more robust

coding scheme. Does not

apply to EGPRS TBFs

P351bNumber of CS adaptions

from a given coding

scheme to a more robust


apply to EGPRS TBFs

P352aNumber of CS adaptions

from a given coding

scheme to a less robust


apply to EGPRS TBFs

P351aNumber of CS adaptions

from a given coding

scheme to a less robust


apply to EGPRS TBFs

UplinkDownlink

Coding scheme adaptation






1 � 3 � 177


QoS Indicators, DL CS Usage, Graph

GPRS DL useful RLC traffic

01000000020000000300000004000000050000000600000007000000080000000

10/31

/2005

11/02

/2005

11/04

/2005

11/06

/2005

11/08

/2005

11/10 /20

05

11/12 /20

05

11/14 /20

05

11/16 /20

05

11/18 /20

05

11/20 /20

05

11/22 /20

05

11/24 /20

05

11/26 /20

05

11/28 /20

05

11/30 /20

05

12/02

/2005

12/04

/2005

12/06

/2005

12/08

/2005

12/10

/2005

12/12

/2005

12/14

/2005

12/16 /20

05

0102030405060708090100

CS4 usef

CS3 usef

CS2 usef

CS1 usef

%io CSx usef






1 � 3 � 178


QoS Indicators, DL MCS Usage

0%

20%

40%

60%

80%

100%

B8 TRX class 2 & 4(MaxMCS=9)

B9(MaxMCS=9)

B9(MaxMCS=8)

MCS3

MCS4

MCS5MCS6

MCS7

MCS8

MCS9

MCS2

MCS1

High proportionof MCS5 due to High

Ater Usage

Thanks to�Dynamic Abis

�Statistical Multiplexing

High usageof MCS9

Better usageof MCS8

Caution: animated slide (with hidden objects).






1 � 3 � 179


QoS Indicators, UL MCS Usage

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

B8 (GMSK only) B9 (8PSK in UL)

8PSK being used

in UL right after

B9 migration

Thanks to:�Dynamic Abis�Statistical Mux�8 PSK in UL

High Usage

of MCS9

during UL

FTP tests

MCS3

MCS4

MCS5MCS6

MCS7

MCS8

MCS9

MCS2MCS1

Caution: animated slide (with hidden objects).






1 � 3 � 180

7 Cell Reselection






1 � 3 � 181

7 Cell Reselection

NC0, Success

MSMFS



Packet DL Ack/Nack



PDTCHDL

PACCHUL


SGSNMFS

target cell


reselection

LLC PDU

(TLLI,new BVCI)

FLUSH-LL

(TLLI,old BVCI)

FLUSH-LL ACK

(TLLI)

P436

NC0 reselection success



P434d

DL TBF release

P434c

UL TBF release

P396aP396b

RADIO STATUS

Counter P434c (resp.P434d) gives the number of UL (resp. DL) TBFs which have been released due to an NC0

reselection. These TBFs can have been previously counted as abnormally released or acceptably released

due to the reselection depending on the occurrence time of the FLUSH-LL message:

� If the FLUSH-LL message is not received before T_WAIT_FLUSH expiry after the TBF was released due to

radio link failure then the previous TBF release is considered as abnormal and counter P434c/P434d

counting the number of DL/UL TBF acceptable release due to reselection is not incremented. Instead a TBF

abnormal release due to Radio and counters P302b_x/P302c_x are incremented.

� If the FLUSH-LL message is received before T_WAIT_FLUSH expiry after the TBF was released due to radio

link failure then the previous TBF release is considered as acceptable and P434c/P434d is incremented.

If the FLUSH-LL message is received before the radio link failure occurs the TBF is released and

P396b/P396a counter is incremented.

P436 provides the number of successful NC0 cell reselection when the mobile was in Packet Transfer Mode

in the old cell.






1 � 3 � 182

7 Cell Reselection

NC2, Request / Success



MSMFS


SGSN

Packet measurement reportPACCHUL

MFS

target cell

NC2 cell reselection

request

Packet cell change order, polling

PACCHDLnew cell (BCCH,BSIC) Packet control ackThe MS

switches to the new cell

T3158

expiry

T3158


locally

LLC PDU

(TLLI,new BVCI)FLUSH-LL

(TLLI,old BVCI)FLUSH-LL ACK

(TLLI)

T_ACK_WAIT

T_WAIT_FLUSH

P226

NC2 cell reselectionsuccess

P224

DL TBF release

P227

UL TBF release

P223

P221 P222

UL TBF DL TBF

If a PCCO is sent for a MS supporting a DL TBF and an UL TBF, then both P223 and P226 are incremented.

If a FLUSH is received for a MS supporting a DL TBF and an UL TBF, then both P224 and P227 are

incremented.






1 � 3 � 183

7 Cell Reselection

NC2, Request / Success per Causes



MSMFS


SGSN


MFS

target cell

NC2 cell reselectionrequest for cause:

too bad uplink quality

too bad downlink

quality

too low downlink level

better neighbor cellPacket cell change order, polling

PACCHDLnew cell (BCCH,BSIC) Packet control ack

The MS switches to the new cell

T3158 expiry

T3158


locally

LLC PDU(TLLI,new BVCI)

FLUSH-LL(TLLI,old BVCI)

FLUSH-LL ACK

(TLLI)

T_ACK_WAIT

T_WAIT_FLUSH

P433d

P433c

P433a

P433b

NC2 cell reselectionsuccess for cause:

too bad uplink quality

too bad downlink quality

too low downlink level

better neighbor cell

P435d

P435c

P435a

P435b

P434b

DL TBF release

P434a

UL TBF release

P396aP396b






1 � 3 � 184

7 Cell Reselection

NC2, Failure

UL transfer establishment in the new cellis impossible

MS

DL transfer

SGSN


MFS

target cell

NC2 cell reselectionrequest

Packet cell change order, pollingPACCHDLnew cell (BCCH,BSIC)

Packet control ackThe MS

switches to the new cell

T3158expiry

T3158


locally

T_ACK_WAIT

T_WAIT_FLUSH

P437b

Target cell not rejected

P437a

Target cell

rejected

Packet channel request

Packet uplink assignment

USF scheduling

Packet cell change failure

RACH

AGCH

PDTCH

PACCH

P228

P225

UL TBF DL TBF

P464

MFS

serving cell

The above case assumes that MPDCH is configured in the cell.

When receiving the PACKET CELL CHANGE FAILURE message, the MFS will increment either P437a or P437b

according to the cause value reported by the MS in the message.

Counter P464 aims to count rejection due to load in target cell

Counter P228/P225 is incremented in case of the MS reports to the MFS a Packet Cell Change Failure

message (PCCF)

Counter P437a is incremented if the cause included in the PCCF reported is one of the following

� "Frequency not implemented”

� "No response on target cell”

� "Immediate Assign Reject or Packet Access Reject on target cell”

Counter P437a is incremented if the cause included in the PCCF reported is one of the following:

� "On going CS connection”

� "MS in GMM Standby state”

� Forced to the Standby state”






1 � 3 � 185

7 Cell Reselection

QoS Degradation

� QoS degraded due to cell reselection

CS 1

CS 2

Throughput [kbit/s]

Time[s]t1 t2 t3 t5t4t0

AverageThroughput

Throughput

TBF 1 (Cell 1) TBF 2 (Cell 2)

Data “Call” Duration

1. CS change 1. CS change

CellRe-Selection

4 sec






1 � 3 � 186

7 Cell Reselection

NACC and (P)SI Status

� QoS improved with NACC and (P)SI status

CS 1

CS 2

Throughput

[kbit/s]

Time

[s]t1 t2 t3 t5t4t0

Throughput

AverageThroughput

TBF 1 (Cell 1) TBF 2 (Cell 2)

Data “Call” Duration

1. CS change1. CS change

CellRe-Selection

1 sec






1 � 3 � 187

7 Cell Reselection

NACC and (P)SI Status [cont.]

MSMFSCell A

UL or DL TBF

Packet Cell Change

NotificationRetrieval of SI

instances

Packet Neighbor Cell Data (SI1)



Packet Cell Change Continue

MFSCell B

� In the source cell

P458

P459

Number of times the procedure of broadcast of neighbor (P)SI messages is invoked

Signaling load induced in the

cell by the procedure of

broadcast of neighbor (P)SI

messages

P458

NC0 MODE

P460c

P460b

Minimum Network Assisted cell reselection duration

Maximum Network Assisted cell reselection duration.

P212 (time)

reception of FLUSH LL

The duration of a NACC cell reselection is measured in the source cell between the

start of emission of Packet Neighbour Cell Data messages (following the reception

of the Packet Cell Change Notification message) and the reception of the Flush-LL

message. The source cell is the cell where the cell reselections are outgoing.

The duration of a NACC cell reselection is measured in the source cell between the start of emission of PacketNeighbour Cell Data messages and the reception of the Flush-LL message






1 � 3 � 188

7 Cell Reselection


T_Wait_Flush

T_Ack_Wait

On going UL TBF (8)

On going UL or DL TBF

MS BSSServing cell

Packet Cell Change Order / PACCH

Packet Measurement Report / PACCH

BSSTarget cell

SGSN

Packet Control Acknowledgement / PACCH(4)

Packet Channel Request / PRACH

Packet Uplink Assignment / PCCCH

UL LLC PDU [TLLI]

FLUSH-LL PDU [TLLI, old BVCI]

FLUSH-LL-ACK PDU [TLLI, “deleted”]

Packet Neighbour Cell Data (SI3) / PDCH

Packet Neighbour Cell Data (S1) / PDCH

Packet Neighbour Cell Data (SI13) / PDCH

P458

NC2 MODE

P209 (time)






1 � 3 � 189

7 Cell Reselection


MSMFSCell A

MFSCell B

Packet SI Status (SI2, SI2bis, SI2ter msg type missing)

Packet Serving Cell Data (SI2)

Packet Serving Cell Data (SI2bis)

Packet Serving Cell Data (SI2ter)

UL or DL TBF

UL or DL TBF

� In target cell (P) SI status

P456P457

Number of times the procedure of broadcast of serving cell PSI for Packet PSI Status or the procedure of sending of Packet Serving Cell Data for Packet SI Status is invoked.

Signaling load induced in the cell by the procedure of broadcast of (P)SI messages

P456

P457

This mechanism is applied in both NC0 and NC2

P457:

Number of RLC blocks used:

1) To broadcast a PSI message for Packet PSI Status feature

2) To send a PACKET SERVING CELL DATA message for Packet SI Status feature.






1 � 3 � 190

7 Cell Reselection

Exercise

� Exercise 1: What kind of cell reselection procedure ( NC0 or NC2 / with or without NACC) you can observe in Trace10,11, 12 and Trace13?

� Exercise 2: For each case of cell reselection,

� Find specific messages to NACC (P)SI status if any

� find old and new cell identities.

� Exercise 3 : looking the content of SI Status can you guess which SI where given during NACC procedure

Time allowed:

30 minutes






1 � 3 � 191

7 Cell Reselection

QoS Indicators

� NACC and (P)SI status reselection

� NCO reselection

� NC2 reselection

NC2 reselection

startNumber of requestsNumber of successes, Nb of DL/UL TBF releases

Success rate

Failure causes

time

TBF establishment

end

Target cell rejected

Target cell not rejected

Reselection time Outgoing

Incoming

Max

Avg

Min

Number of successes, Nb of DL/UL TBF releases






1 � 3 � 192

� Cell reselection: ALL = NC0+NC2

7 Cell Reselection

QoS Indicators, NC0

Number of successful cell re-selection P397

Number of successful NC0 cell re-selection P436

NC0+NC2 re-selection

NC0 re-selection






1 � 3 � 193

� Cell reselection: NC2

7 Cell Reselection

QoS Indicators, NC2

(P435a+P435b+P435c+P435d) / (P433a+P433b+P433c+P433d)NC2 cell re-selection success rate

P435a+P435b+P435c+P435dNumber of NC2 cell re-selection successes

P433a+P433b+P433c+P433dNumber of NC2 cell re-selection requests

P435dNumber of NC2 cell re-selection success cause PT4 (too bad uplink quality)

P435cNumber of NC2 cell re-selection success cause PT3 (too bad downlink

quality)

P435bNumber of NC2 cell re-selection success cause PT2 (better neighbour cell)

P435aNumber of NC2 cell re-selection success cause PT1 (too low downlink level)

(P433b) / (P433a+P433b+P433c+P433d) * 100Ratio of NC2 re-selection cause Better Condition

(P433a+P433c+P433d) / (P433a+P433b+P433c+P433d) * 100Ratio of NC2 re-selection cause Emergency

P433dNumber of NC2 cell re-selection request cause PT4 (too bad uplink quality)

P433cNumber of NC2 cell re-selection request cause PT3 (too bad downlink

quality)

P433bNumber of NC2 cell re-selection request cause PT2 (better neighbour cell)

P433aNumber of NC2 cell re-selection request cause PT1 (too low downlink level)

NC2 re-selection

KPI

KPI






1 � 3 � 194

7 Cell Reselection

QoS Indicators, NC2 [cont.]

Maximum duration of successful outgoing NC2 cell reselections (measured in the source cell)

P431b

Number of NC2 cell reselection failures reported by the MS which does not lead to reject the target cell for a while.

P437b

Minimum duration of successful outgoing NC2 cell reselections (measured in the source cell)

P431c

Average duration of successful outgoing NC2 cell reselections (measured in the source cell)

P431a

Maximum duration of successful incoming intra-RA intra-MFS NC2 cell reselections (measured in the target cell).

P432b

Minimum duration of successful incoming intra-RA intra-MFS NC2 cell reselections (measured in the target cell).

P432c

Average duration of successful incoming intra-RA intra-MFS NC2 cell reselections (measured in the target cell).

P432a

Rate of NC2 failures due to BSS problem(((P433a) + (P433b) + (P433c) +(P433d)) - ((P435a) + (P435b) + (P435c) + (P435d)) - (P437b) - (P437a) – P464) / ((P433a) + (P433b) + (P433c) +(P433d))

Number of NC2 cell reselection failures reported by the MS due to load (cause : "immediate assign reject" or "packet access reject on target cell")

P464

Number of NC2 cell reselection failures reported by the MS which leads to reject the target cell for a while.

P437a

B10

Removed B10

Removed B10

P432x counters are taking into account only the Cell Reselections for which Serving and Target cells belong

to the same RA and the same MFS.






1 � 3 � 195

7 Cell Reselection

QoS Indicators, NC2 [cont.] B10

P212Cumulated time of the successful Network Assisted cell reselection duration in NC0 mode

TIME_SOURCE_NACC_CELL_RESEL

P209 / (P435a + P435b + P435c + P435d)

Average duration of successful outgoing NC2 cell reselections (measured in the source cell).

GPRS_NC2_reselect_source_cell_time_avg

P211Number of successful incoming intra-RA intra-MFS NC2 cell reselections (measured in the target cell).

NB_TARGET_NC2_CELL_RESEL

(P212 / P213)*1000Cumulated time of the successful Network Assisted cell reselection duration in NC0 mode

GPRS_NC_reselect_NACC_avg_duration

P210Cumulated time duration of successful incoming intra-RA intra-MFS NC2 cell reselections (measured in the target cell).

TIME_TARGET_NC2_CELL_RESEL

P209Cumulated time duration of successful outgoing NC2 cell reselections (measured in the source cell).

TIME_SOURCE_NC2_CELL_RESEL


P209:

� Within the granularity period, the MFS cumulates the duration of each successful outgoing NC2 cell

reselections triggered by the BSS in the source cell.

� The duration of a NC2 cell reselection is measured in the source cell between the acknowledgement of

the Packet Cell Change Order message and the reception of the Flush-LL message. The source cell is the

cell where the NC cell reselections are outgoing.

P210:

� Within the granularity period, the MFS cumulates the duration of the successful incoming intra-RA intra-

MFS NC2 cell reselections triggered by the BSS in the source cell.

� The duration of a NC2 cell reselection is measured in the source cells between the acknowledgement of

the Packet Cell Change Order message and the reception of the Flush-LL message. These measures are

forwarded to the target cell in the intra-MFS TLLI Rerouting Confirm message and then cumulated in the

target cell.

� The source cells are the cells where the NC cell reselections are outgoing, whereas the target cell is the

cell where the NC cell reselections are incoming.

P211:

� Within the granularity period, the MFS counts the number of each successful outgoing NC2 cell

reselections triggered by the BSS in the source cell.

� A NC2 cell reselection is successful when in the source cells after the acknowledgement of the Packet

Cell Change Order message is received , the Flush-LL message is received.

� These measures are forwarded to the target cell in the intra-MFS TLLI Rerouting Confirm message and

then cumulated in the target cell.

� The source cells are the cells where the NC cell reselections are outgoing, whereas the target cell is the

cell where the NC cell reselections are incoming.






1 � 3 � 196

7 Cell Reselection

QoS Indicators, NC2 [cont.]

Number of FLUSH-LL PDU received after a Packet Cell Change Order has been sent to the MS while in UL

NB_FLUSH_NC2_CELL_RESEL_UL_TBFP227

Number of Packet Cell Change Failure received from the MS after a Packet Cell Change Order has been sent to the MS while in DL transfer

NB_PCCF_NC2_CELL_RESEL_DL_TBFP225

Number of FLUSH-LL PDU received after a Packet Cell Change Order has been sent to the MS while in DL transfer.

NB_FLUSH_NC2_CELL_RESEL_DL_TBFP224

Number of Packet Cell Change Failure received from the MS after a Packet Cell Change Order has been sent to the MS while in UL transfer.

NB_PCCF_NC2_CELL_RESEL_UL_TBFP228

Number of Packet Cell Change Order messages sent while in UL transfer.

NB_PCCO_NC2_CELL_RESEL_UL_TBFP226

Number of Packet Cell Change Order messages sent while in DL transfer.

NB_PCCO_NC2_CELL_RESEL_DL_TBFP223

Number of Packet Cell Change Order acknowledged by the MS while in DL transfer

NB_PCCO_ACK_DL_NC2_CELL_RESELP222

Number of Packet Cell Change Order acknowledged by the MS while in UL transfer

NB_PCCO_ACK_UL_NC2_CELL_RESELP221

DefinitionNameCounter number






1 � 3 � 197

7 Cell Reselection

QoS Indicators, NACC (P)SI Status

Average Network Assisted cell reselection duration.AV_SOURCE_NACC_CELL_RESEL_TIMEP460a

Signaling load induced in the cell by the procedure of broadcast of neighbor (P)SI messages

NB_NEIGH_PSI_MESP459

Minimum Network Assisted cell reselection duration.MIN_SOURCE_NACC_CELL_RESEL_TIMEP460c

Maximum Network Assisted cell reselection duration.MAX_SOURCE_NACC_CELL_RESEL_TIMEP460b

Number of times the procedure of broadcast of neighbor (P)SI messages is invoked

NB_NEIGH_PSI_PROCP458

Signaling load induced in the cell by the procedure of broadcast of (P)SI messages

NB_PSI_MESP457

Number of times the procedure of broadcast of serving cell PSI for Packet PSI Status or the procedure of sending of Packet Serving Cell Data for Packet SI Status is invoked.

NB_PSI_PROCP456

DefinitionNameCounter

number

B10

Removed B10

.






1 � 3 � 198

7 Cell Reselection

End-User QoS Improvement with NC2

� Enhanced cell reselection can be easily tested and evaluated through drive test route

DL FTP transfer of a file

In a bi-band network (GSM900,GSM1800)

GSM1800 cells are favored in CS idle

mode:

CELL_RESELECT_OFFSET = 20dB

Route length is about 1.150 Km

Two 900 cells and two 1800 cells are

covering

MS is GPRS multi-slot class 8 (4+1)






1 � 3 � 199

7 Cell Reselection

End-User QoS Improvement with NC2 [cont.]

� Gain in throughput

� NC034,7 kbits/s

� NC2 + GPRS redirection 40,2 kbits/s

9 reselectionsduring transfer

2 reselectionsduring transfer

0

100

200

300

400

500

600

1 33

65

97

12

9

16

1

19

3

22

5

25

7

28

9

32

1

35

3

0

10

20

30

40

50

60

ServBCCH

RLC_Throughput_DL

2 interruptions

0

10

20

30

40

50

60

1 28

55

82

10

9

13

6

16

3

19

0

21

7

24

4

27

1

29

8

32

5

0

100

200

300

400

500

600

700

RLC_Throughput_DL

ServBCCH

9 interruptions






1 � 3 � 200









1 � 3 � 201

End of ModuleDescription of the Main BSS GPRS QoS Counters and Indicators






Module 4Detection of the Main BSS GPRS QoS Problems


Section 1EGPRS QoS







EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Detection of the Main BSS GPRS QoS Problems

1 � 4 � 2

Blank Page




Document History






1 � 4 � 3

Module Objectives


� Detect the main GPRS QoS problems of the Alcatel-Lucent BSS






1 � 4 � 4








1 � 4 � 5

Table of Contents


1 General Principles 72 Main BSS GPRS QoS Problems 12






1 � 4 � 6









1 � 4 � 7

1 General Principles






1 � 4 � 8


KPI, Warning Indicator

� A lot of QoS indicators are computed from BSS GPRS counters

� QoS indicators that will be followed-up by management are called KPI: Key Performance Indicator

� Among all BSS GPRS QoS indicators some are used to detect QoS problems: they are called WARNING indicators

� usually all KPIs

� other major indicators as from radio optimizer view






1 � 4 � 9


QoS Threshold, Sampling Indicator

� A WARNING indicator is often attached a QoS threshold value to decide if the indicator value is bad or not

� In case a WARNING indicator value is considered as bad then another indicator called the SAMPLING indicator and attached to the WARNING indicator must be checked

� A SAMPLING indicator is attached a sample threshold value to decide if the WARNING indicator value is relevant or not






1 � 4 � 10


QoS Problem Detection

List of BSS QoS indicators

I1. I2. I3. I4. I5, I6, I7, I8,

etc

Are some Warning

indicator values bad?

end

Check the related

Sampling indicator

value

Is the Warning indicator

value relevant?

Analyze QoS

problem

no

no

yes

yes






1 � 4 � 11


QoS Problem Detection, Exercise

� Exercise: Using analogy with BSS GSM QoS indicators find the Sampling indicator attached to each of the following GPRS Warning indicators:

� TBF establishment success rate

� TBF drop rate

� NC2 Cell reselection success rate

Time allowed:

10 minutes






1 � 4 � 12

2 Main BSS GPRS QoS Problems






1 � 4 � 13


Exercise 1: List Them

� Exercise 1: List the main BSS QoS problems seen as a QoS degradation by the end user

� BSS GPRS QoS problems are relating to Data transfer problems between the MS and the GPRS Core network, which are due to the BSS

Time allowed:

15 minutes






1 � 4 � 14


Exercise 2: Find Warning and Sampling Indicators

� Exercise 2: Find the Warning and Sampling indicators which will be used to detect each of these problems:

� Data transfer not established

� Data transfer degraded

� Data transfer interrupted

� Data transfer dropped

Time allowed:

15 minutes






1 � 4 � 15


Exercise 3: UL Data Transfer Establishment Degradation

� Exercise 3: Find the Warning indicator degraded by difficulties to establish a UL TBF resulting in a TBF establishment after MS repetitions of channel request

� Can this problem be identified through QoS indicators?

� If not, what must be done to find the cause of the UL data transfer establishment degradation?

Time allowed:

15 minutes






1 � 4 � 16


Exercise 4: DL Data Transfer Establishment Degradation

� Exercise 4: Find the Warning indicator degraded by difficulties to establish a DL TBF resulting in a TBF establishment after MFS repetitions of channel assignment

� Can this problem be identified through QoS indicators?

� If not, what must be done to find the cause of the DL data transfer establishment degradation?

Time allowed:

5 minutes






1 � 4 � 17









1 � 4 � 18

End of ModuleDetection of the Main BSS GPRS QoS Problems






Module 5Analysis of the Main BSS GPRS QoS Problems


Section 1EGPRS QoS







EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Analysis of the Main BSS GPRS QoS Problems

1 � 5 � 2

Blank Page




Document History






1 � 5 � 3

Module Objectives


� Analyze the main GPRS QoS problems of the Alcatel-Lucent BSS






1 � 5 � 4








1 � 5 � 5

Table of Contents


1 Find the causes of a BSS GPRS QoS problem 72 Characterize the QoS Indicators Used in the Analysis of a BSS GPRS QoS Problem103 What Kind of QoS Problem Is Recorded in the Trace? 16






1 � 5 � 6









1 � 5 � 7

1 Find the causes of a BSS GPRS QoS problem






1 � 5 � 8

1 Find the Causes of a BSS GPRS QoS Problem

Exercise 1a: Find the Probable Causes

� Exercise 1a: Find the probable causes of a BSS GPRS QoS problem

Time allowed:

30 minutes




Exercise 1a: Find the probable causes of a BSS GPRS QoS problem

For each of the 4 typical BSS GPRS QoS problems, mark the probable cause(s)

each cause corresponding to a specific BSS PM counter (1)

TBF establishment

failure

TBF throughput degradation

TBF interruption TBF drop

MS suspend

Gb

Radio

Cell reselection

Congestion

MS error (1)

Fast PDCH pre-emption of the PDTCH carrying the PACCH of the TBF

Fast PDCH pre-emption of the PDTCH carrying only a PDTCH of the TBF

BSS problem (2)

Sub-optimal usage of radio resources (3)

(1) MS error are not counted in a specific counter(2) any software or hardware failure, occuring in the BSS, provok ing a TBF problem not counted as another cause (3) any reason why a mobile involved in a TBF get a data throughput lower than its transfer capability

probable cause

QoS problem






1 � 5 � 10

1 Find the Causes of a BSS GPRS QoS Problem

Exercise 1b: Find the more Detailed Reasons

� Exercise 1b: Find a more detailed reason for some of the probable

causes of a BSS GPRS QoS problem

Time allowed:

60 minutes




Exercise 1b: Find a more detailed reason for some of the probable causes of a BSS GPRS QoS problem

Congestion Radio Gb

Sub-optimal usage of

radio resources

Fast PDCH pre-emption

of the PDTCH

carrying the PACCH of the TBF

Fast PDCH pre-emption

of the PDTCH carrying only a

PDTCH of the TBF

MS suspend

Cell reselection

Interference

NC2 cell reselection not activated

NC2 cell reselection not efficient

Lack of PDCH resources (1)

Lack of CCCH resources

Lack of Abis resources

Lack of Ater resources

Lack of GPU resources

T_PDCH_PREEMPTION parameter value too low

BSS SW or HW failure

GSS SW or HW failure

Re-allocation trigger T1 is not efficient

Abis MW problem

System or protocol error between BSS and GSS

Coverage

Abis signalling overload

Bad setting of cell reselection parameters

Bad setting of CS/MCS adaptation parameters

High CS traffic

High PS traffic

(1) can be due to: tow low MAX_PDCH parameter value, too high CS traffic, too high PS traffic,too long Delayed DL TBF Release phase, poor re-allocation algorithm efficiencyBSS SW or HW failure

reason

probable cause






1 � 5 � 12

2 Characterize the QoS Indicators Used in the Analysis of a BSS GPRS QoS Problem






1 � 5 � 13


Exercise 2a: TBF Establishment Failure

� Exercise 2a: Characterize the QoS indicators used in the analysis of a

TBF establishment failure

Time allowed:

30 minutes




Exercise 2a: Characterize the QoS indicators used in the analysis of a TBF establishment failure

Congestion% TBF establishment failure

due to congestion

Lack of PDCH resources% TBF establishment failure

due to radio congestion

bad MAX_PDCH

parameter settingMaximum nb of established SPDCH

Average MAX_SPDCH_LIMIT value

MAX_SPDCH_LIMIT reduction rate

Check MAX_PDCH parameter

value

high CS traffic Average MAX_SPDCH_LIMIT value

Nb of PDCH released after having

been marked by soft pre-emption

Average nb of TBF candidates to

T1 re-allocation per PDCH

released after having been marked

by soft pre-emption

high PS traffic Maximum nb of established SPDCH



too long Delayed DL TBF

release phase

% of time established DL TBFs are

active

Ratio of DL TBF resumptions per

established DL TBF

Average TBF duration

Average MS session duration

Average number of GPRS sessions

per call

Check


parameter value

poor re-allocation

algorithm efficiency

Average nb of TBF established per

MS session

Nb of TBF re-allocation requests

Re-allocation success rate

BSS SW or HW failureuse GSM indicators and BSS

equipement alarms

GSS SW or HW failureuse GSS indicators and/or GSS

equipment alarms

Lack of Abis resources% TBF establishment failure

due to Abis congestion

Lack of Ater resources% TBF establishment failure

due to Ater congestion


% TBF establishment failure

due to (DSP+CPU) GPU

congestion




Exercise 2a: Characterize the QoS indicators used in the analysis of a TBF establishment failure (suite)

Radio% TBF establishment failure

due to radio

Coverage use GSM indicators

Interference use GSM indicators

Abis MW problemuse GSM indicators and Abis

transmission alarms


equipement alarms

NC2 cell reselection not

activated

Number of NC2 cell

reselection requests

Lack of CCCH resources use GSM indicators

Gb% TBF establishment failure

due to Gb pb

system or protocol error

between BSS and GSStrace Gb interface

GSS SW or HW failure

BSS% TBF establishment failure

due to BSS pb

BTS, BSC or MFS

software or hardware

failure

use GPRS LAPD counters,

BSS indicators and alarms

trace Abis, Ater interface

MS errorsystem or protocol error

between BSS and MStrace Abis, Ater interface






1 � 5 � 16

2 Characterize the QoS indicators used in the analysis of a BSS GPRS QoS Problem

Exercise 2b: TBF throughput degradation

Time allowed:

20 minutes

� Exercise 2b: Characterize the QoS indicators used in the analysis of a TBF throughput degradation




Exercise 2b: Characterize the QoS indicators used in the analysis of a TBF throughput degradation

Sub-optimal usage

of radio resources

% time MS engaged in a TBF in

the direction of the bias and they

are granted the maximum nb of

TS they support in that direction

Lack of PDCH resources% of partial TS allocation

success

bad MAX_PDCH

parameter settingMaximum nb of established SPDCH



Check MAX_PDCH parameter value


Nb of PDCH released after having been

marked by soft pre-emption

Average nb of TBF candidates to T1 re-

allocation per PDCH released after

having been marked by soft pre-

emption

high PS traffic Maximum nb of established SPDCH



too long Delayed DL TBF

release phase% of time established DL TBFs are active

Ratio of DL TBF resumptions per

established DL TBF

Average TBF duration

Average MS session duration

Average number of GPRS sessions per

call

Check T_NETWORK_RESPONSE_TIME

parameter value

poor re-allocation

algorithm efficiency

Average nb of TBF established per MS

session

Nb of TBF re-allocation requests

Re-allocation success rate


equipement alarms

GSS SW or HW failureuse GSS indicators and/or GSS

equipment alarms




Exercise 2b: Characterize the QoS indicators used in the analysis of a TBF throughput degradation (suite)

Sub-optimal usage

of radio resources

% time MS engaged in a

TBF in the direction of the

bias and they are granted

the maximum nb of TS they

support in that direction

Lack of Abis resources% TBF establishment failure

due to Abis congestion

Cumulative time during a

GCH resource is busy in the

cell

Cumulative time during

which there is a deficit of

GCH resources in the cell

Maximum number of GCH

in deficit reached in the cell

Lack of Ater resources% TBF establishment failure

due to Ater congestion

% of time the GPU is in GCH

congestion


% TBF establishment failure

due to (DSP+CPU) GPU

congestion

% of time the SPDCH are

degraded due to Ater

congestion

Bad setting of CS (or

MCS) adaptation

parameters

Ratio of RLC blocks

transmitted on most robust

CSx (or MCx)

% of retransmission of RLC

blocks for CS (or MCS)

TBF_CS_INIT

Check CS and MCS

adaptation paramaters value

Bad setting of CS (or

MCS) adaptation

parameters

Ratio of RLC blocks


CSx (or MCx)



TBF_CS_INIT

Check CS and MCS

adaptation paramaters value

Fast PDCH pre-

emption of the

PDTCH carrying only

a PDTCH of the TBF

Nb of PDCH released after

having been marked by soft

pre-emption

high CS trafficAverage MAX_SPDCH_LIMIT

value

Average nb of TBF

candidates to T1 re-

allocation per PDCH

released after having been

marked by soft pre-emption

Radio

Coverage / Interference

Ratio of RLC blocks


CSx (or MCx)



TBF_CS_INIT

use GSM indicators






1 � 5 � 19


Exercise 2c: TBF Interruption

� Exercise 2c: Characterize the QoS indicators used in the analysis of a

TBF interruption

Time allowed:

15 minutes




Exercise 2c: Characterize the QoS indicators used in the analysis of a TBF interruption

Fast pre-emption

of the PDCH

carrying the

PACCH of the TBF

TBF release rate due to fast

pre-emption

Re-allocation trigger T1

is not efficient

TBF re-allocation trigger T1

success rate

Check

T_PDCH_PREEMPTION

parameter value

Lack of PDCH resource see previous cases

high PS traffic MAX_SPDCH_LIMIT reduction rate

% TBF establishment failure due to

radio congestion

MS SuspendTBF release rate due to MS

suspend


Nb of PDCH released after having

been marked by soft pre-emption

Average nb of TBF candidates to

T1 re-allocation per PDCH

released after having been marked

by soft pre-emption

Average number of GPRS sessions

per call

Cell reselectionTBF release rate due to cell

reselection


activated

Number of NC2 cell


NC2 cell reselection is

not efficient

NC2 cell reselection success

rate

Number of NC2 cell


Check NC2 cell reselection

parameters value

CAUTION: % TBF acceptable release rate can increase be due to the modification of the duration of the “delayed”

state phase of the Delayed DL TBF release procedure after parameter tuning.

Therefore check evolution of the indicator : % TBF acceptable rele






1 � 5 � 21


Exercise 2d: TBF drop

� Exercise 2c: Characterize the QoS indicators used in the analysis of a

TBF drop

Time allowed:

15 minutes




Exercise 2d: Characterize the QoS indicators used in the analysis of a TBF drop

Radio TBF drop rate due to radio

Coverage use GSM indicators

Interference use GSM indicators

Abis MW problemuse GSM indicators and Abis

transmission alarms


equipement alarms

MS errorTBF drop rate due to

stagnating TX window

TBF drop rate due to

blocking situation


between BSS and MStrace Abis, Ater interface

Gb TBF drop rate due to Gb


between BSS and GSStrace Gb interface

BSS TBF drop rate due to BSS

BTS, BSC or MFS

software or hardware

failure

use GPRS LAPD counters,

BSS indicators and alarms

trace Abis, Ater interface

Cell reselection TBF drop rate due to radio


activated and NC0 cell

reselection takes long time

Number of NC2 cell

reselection request

Number of NC0 cell

reselection success per call

CAUTION: % TBF abnormal release rate can increase be due to the modification of the duration of the “delayed”

state phase of the Delayed DL TBF release procedure after parameter tuning.

Therefore check evolution of the indicator : % TBF acceptable releas






1 � 5 � 23

3 What Kind of QoS Problem Is Recordedin the Trace?






1 � 5 � 24

3 What Kind of QoS Problem Is Recorded in the Trace?

Exercise

� What kind of BSS GPRS QoS problem you can observed in the trace 20?

Time allowed:

15 minutes






1 � 5 � 25









1 � 5 � 26

End of ModuleAnalysis of the Main BSS GPRS QoS Problems






1 � 5 � 27


Exercise 2d: TBF Drop

� Exercise 2d: Characterize the QoS indicators used in the analysis of a TBF drop

Time allowed:

10 minutes






Module 6Appendix


Section 1EGPRS QoS







EVOLIUM � Introduction to GPRS and E-GPRS QoS Monitoring - B10EGPRS QoS � Appendix

1 � 6 � 2

Blank Page




Document History






1 � 6 � 3

Module Objectives


� Describe …

� List …

� Explain …

� Identify ...






1 � 6 � 4








1 � 6 � 5

Table of Contents


1 Real Radio Drop 72 (P)SI Messages Details 103 Exercises on NACC (P)SI STATUS 134 KPIs 15

4.1 Main KPIs 164.2 Important KPIs 17

5 What’s New or Modified in B10 20






1 � 6 � 6









1 � 6 � 7

1 Real Radio Drop






1 � 6 � 8

1 Real Radio Drop

Radio Drop and Reselection

3105Overload

FLUSH FLUSH

PIM

397

No ReleaseNo Counter

302

396

434

END

Cell Reselection

YES

NO

FLUSH ON TIMEFLUSH LATE= All - On Time

ALL FLUSHs

NO

NO (PTM)

NO

YESYES

YES

COUNTED

Real Radio Drop= Counted – Late

= Counted – (All – On Time)= 302 – (434 – 396)






1 � 6 � 9

1 Real Radio Drop

Radio Drop and Suspend

3105Overload

SUSPEND SUSPEND

302

98a

98c

END

VOICE CALL

NO

SUSPEND ON TIME SUSPEND LATE= All - On Time

ALL SUSPENDs

NO NO

YESYES

YES

COUNTED

Real Radio Drop= Counted – Late= Counted – (All – On Time)= 302 – (98c – 98a)






1 � 6 � 10

2 (P)SI Messages Details






1 � 6 � 11


SI Messages Details

� Coding of the SI typical message in PNCD/PSCD messages

� SI 1 19

� SI 2 1A

� SI 2 bis 02

� SI 2 ter 03

� SI 2 quater 07

� SI 3 1B

� SI 4 1C

� SI 5 1D

� SI 5 bis 05

� SI 5 ter 06

� SI 6 1E

� SI 7 1F

� SI 8 18

� SI 9 04

� SI 13 00

� SI 14 01

� SI 15 44

� SI 16 3D

� SI 17 3E

� SI 18 40

� SI 19 41

� SI 20 42






1 � 6 � 12


PSI Messages Details

� Coding of the PSI typical message in PNCD messages

� PSI1 C4

� PSI2 C8

� PSI3 CC

� PSI3 bis D0

� PSI3 ter F0

� PSI3 quater F4

� PSI4 D4

� PSI5 D8

� PSI6 C0

� PSI7 E0

� PSI8 E4

� PSI13 DC

� PSI14 E8

� PSI15 F8






1 � 6 � 13

3 Exercises on NACC (P)SI STATUS






1 � 6 � 14

3 Exercises on NACC (P)SI STATUS

Exercise 1

� A/ extracting Packet Neighbor Cell Data message trace 12 could you find what are the SI “Message Type » number sent to the mobile ?

� B/ extracting PSI status message in the same trace could find what are SI message missing for the Mobile?

� For your help, please use the information in previous 2 pages

Time allowed:

20 minutes






1 � 6 � 15

4 KPIs






1 � 6 � 16

4 KPIs

4.1 Main KPIs

� Total number of TBF establishment requests

� TBF establishment success rate

� Drop rate

� Acceptable release rate

� Normal release rate

� In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in CS-x

� PDTCH RLC block CSx / (CS1+CS2+CS3+CS4) ratio

� PDTCH RLC block retransmission rate in GPRS ack mode

� In RLC ack mode, ratio of useful RLC blocks sent in RLC acknowledged mode on PDTCH and encoded in MCS-x

� In RLC ack mode, rate of RLC retransmitted data bytes sent on PDTCH and encoded in MCS-x

� Number of NC2 cell re-selection requests

� NC2 cell reselection success rate






1 � 6 � 17

4 KPIs

4.2 Important KPIs




DL TBF Establishment

Request GPRS_DL_TBF_Request TRDTERQN

% allocated GPRS_DL_TBF_estab_allocated_rate QRDTEAPR

Success GPRS_DL_TBF_success TRDTESUN

% Success GPRS_DL_TBF_success_rate QRDTESUR

UL TBF Establishment

Request GPRS_UL_TBF_request TRUTERQN

% allocated GPRS_UL_TBF_estab_allocated_rate QRUTEAPR

Success GPRS_UL_TBF_success TRUTESUN

% Success GPRS_UL_TBF_success_rate QRUTESUR

DL TBF Reallocation (DL TBF Estab)

% DL Realloc Suc GPRS_DL_TBF_Realloc_Success_Rate TRDRRSUR

UL TBF Reallocation (UL TBF Estab)

% UL Realloc Suc GPRS_UL_TBF_Realloc_Success_Rate TRURRSUR

DL data transfert

% Normal Release GPRS_DL_TBF_normal_release_rate QRDDTNRR

% Acc release GPRS_DL_TBF_acceptable_release_rate QRDDTACR

% drop TBF DL GPRS_DL_TBF_drop_rate QRDDTARR

UL data transfert

% Normal Release GPRS_UL_TBF_normal_release_rate QRUDTNRR

% Acc release GPRS_UL_TBF_acceptable_release_rate QRUDTACR

% drop TBF UL GPRS_UL_TBF_drop_rate QRUDTARR

DL Coding scheme usage (and Partially DL RLC Traffic)

CSx Useful Bytes GPRS_DL_useful_throughput_CSx_bytes_ack TRPDDBYGAN

MCSx Useful Bytes GPRS_DL_useful_throughput_MCSx_bytes_ack TRPDDBYEAN

kbps per EGPRS TBFGPRS_DL_useful_throughput_radio_EGPRS_TBF_avg TRPDDTBEGA

kbps per GPRS TBFGPRS_DL_useful_throughput_radio_GPRS_TBF_avg TRPDDTBGPA

UL Coding scheme usage (and UL RLC Traffic)

CSx Useful Bytes GPRS_UL_useful_throughput_CSx_bytes_ack TRPDUBYGAN

MCSx Useful Bytes GPRS_UL_useful_throughput_MCSx_bytes_ack TRPDUBYEAN

kbps per EGPRS TBFGPRS_UL_useful_throughput_radio_EGPRS_TBF_avg TRPDUTBEGA

kbps per GPRS TBFGPRS_UL_useful_throughput_radio_GPRS_TBF_avg TRPDUTBGPA




DL RLC trafic

% CSx RetransGPRS_DL_RLC_PDTCH_CSx_retransmissing_ack_rate QRDDTRRR

CSx retransGPRS_DL_RLC_bytes_PDTCH_CSx_retransmissing_ack QRDDTRRBCN

MCSx retransGPRS_DL_RLC_bytes_PDTCH_MCSx_retransmissing_ack QRPDDRMN

%MCSx RetransGPRS_DL_RLC_bytes_PDTCH_MCSx_retrans_ack_ratio QRPDDRMO

UL RLC trafic

% CSx RetransGPRS_UL_RLC_CSx_PDTCH_retransmissing_ack_rate QRUDTRRR

CSx retransGPRS_UL_RLC_bytes_PDTCH_CSx_retransmissing_ack QRUDTRRBCN

MCSx retransGPRS_UL_RLC_bytes_PDTCH_MCSx_retransmissing_ack QRPDURMN

%MCSx RetransGPRS_UL_RLC_bytes_PDTCH_MCSx_retrans_ack_ratio QRPDURMO

PDCH Allocation (to be reviewed)

DL Optimal AllocGPRS_DL_biased_and_DL_optimal_allocation_time QRDRRSUT

%DL Optimal Alloc GPRS_DL_biased_and_DL_optimal_alloc_percent QRDRRSUP

UL Optimal AllocGPRS_UL_biased_and_UL_optimal_allocation_time QRURRSUT

%UL Optimal Alloc GPRS_UL_biased_and_UL_optimal_alloc_percent QRURRSUP

PDCH usage Definition Ref Name

GPRS_PDCH_traffic_time Cumulative time during which the slave PDCHs are established and carry at least one UL or DL TBF.(established in GPRS mode or EGPRS mode).

ARPDCUSBUT

GPRS_PDCH_EGPRS_traffic_time Cumulative time during which the slave PDCHs are established and carry at least one UL or DL TBF.(established in EGPRS mode)

ARPDCUSEGT

GPRS_PDCH_EGPRS_traffic_time_ratio Percentage of time during which the established

PDCHs in traffic are supporting EGPRS traffic.

ARPDCUSEGO






1 � 6 � 20

5 What’s New or Modified in B10






1 � 6 � 21

5 What’s New or Modified in B10

Summary

� Reduction of 32 bytes 0 second ping time (no specific counter)

� Dual Transfer Mode (simultaneous CS and PS traffic), new counters:

� Establishment request / attempt / success

� Establishment failure (radio, congestion)

� cumulated time of operation for DTM MS

� Acceptable TBF drop due to CS operation

� GTTP usage

� Extended Dynamic Allocation (more than 2 TS in UL)

� New UL TBF usage counters

� Distribution counters based on GPRS and EGPRS LLC throughput

� TBF radio drop counters more detailed

� New MS capabilities / multislot class breakdown

� Number of useful UL and DL RLC data blocks retransmitted per MCS

� NC2 reselection

� Removed average duration counters

� New cumulated duration counters






1 � 6 � 22









1 � 6 � 23

End of ModuleAppendix

@@COURSENAME - Page 1All Rights Reserved © Alcatel-Lucent @@YEAR

All Rights Reserved © Alcatel-Lucent @@YEAR

@@COURSENAME@@PRODUCT

1

Last But One Page



@@COURSENAME - Page 2All Rights Reserved © Alcatel-Lucent @@YEAR

All rights reserved © Alcatel-Lucent @@YEARPassing on and copying of this document, use and communication of its

contents not permitted without written authorization from Alcatel-Lucent

3FL11829ACAAWBZZA_02

Documents

left blank

rights reserved

gprs qos profiles

gprs qos monitoring

user gprs

radio qos

gprs qos

user qos