UMTS Statistics KPI Training

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UMTS statistics KPI Training

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Performance measurement defn. of

3GPP

Accessibility KPI

Retainability KPI

Mobility KPI

Traffic (erlang / data

volume/throughput)


Performance measurement & KPI in 3GPP

Performance measurements are collected by network elements throughout

the network and 3GPP has defined many (hundreds) of standardized

measurements in the TS 52.402 and 32.4xx series specifications.

To date KPIs have not been standardized across equipment vendors, this

makes it difficult for operators with multiple vendors to easily calculate

network wide KPIs.

Typically equipment vendors/operators will aggregate and combines some

of the measurement and use them to compute some KPIs.

A generalized KPI formula is available in technical report of 3GPP which

uses measurements specified in technical specifications.


Performance measurement defn. of 3GPP TS

3GPP has not defined any Key Performance Indicators

However there are definitions of performance related data

They cover two major groups of performance related data

1.Radio related measurement

2 .Protocol events counter

Performance measurement definition in 3GPP TS defines all tasks for measurement job administration

1.e.g. the start and stop of measurement procedures and how the measurement jobs are intialised,modified & terminated.

2.Max/min/average value of response time measurements & when cumulative counter need to reset

All in all, the standard document gives a good overview on how to store and transport performance data that is already available, but it says nothing about how to compute and analyze it.


UTRAN KPIs described in 3GPP TR 32.814

The below KPIs are formulated as a cooperative effort by eight equipment vendor for 3GGP technical report 32.814 V.7.0.0


User experience

What do user recognize when they use network services?

It is a fact that the subscribers experience – often called user perceived

quality of service is a key factor of business success.

Negative user perceived impression

1. Subscribers are not able to register to the network.

2. Subscribers are not able to setup calls.

3. The calls made are dropped before the called or calling party hangs up.

4. Poor information transmission speed.

5. The quality of transmitted information is bad.


Accessibility KPI

KPI:

RRC setup success ratio

RAB setup success ratio

Granularity could be on each type of service of CS and PS:

Conversational (e.g. voice and video)

Streaming (e.g. streaming video or audio)

Interactive (e.g. browsing)

Background (e.g. emails or file download)


Forward

In WCDMA Signaling procedure, a complete access process

contains following steps:

RRC Establishment

Initial DT

Authentication

Security mode

RAB Assignment


Definition:

RRC Connection Setup Success Rate = RRC connection Success / RRC

Connection Request ×100%

RRC setup request mainly have the following causes 1 ）（ Originating Conversational Call ） 2 ）（ Originating Streaming Call ） 3 ）（ Originating Interactive Call ） 4 ）（ Originating Background Call ） 5 ）（ Originating Subscribed traffic Call ） 6 ）（ Terminating Conversational Call ） 7 ）（ Terminating Streaming Call ） 8 ）（ Terminating Interactive Call ） 9 ）（ Terminating Background Call ） 10 ）（ Emergency Call ） 11 ）（ Call re-establishment ）

RRC Connection setup success rate


RRC Connection attempts & Success rate

WE use the below KPI’s with respect to RRC connection

Total RRC connection attempts & Success rate

Speech RRC attempts & Success rate

Vp RRC Attempts & Success rate

PS interactive RRC attempts & Success Rate

Note: For Speech & Vp RRC connection Attempts & Success rate is not possible

instead we can provide Conversational class RRC attempts & Success rate as

per standards as it is not possible to distinguish video & voice attempts in RRC

connection request phase as we get the establishment cause value for both

voice and video as Conversation class.


RRC setup success ratio

UE SRNCNodeB

RRC RRCRRC Connection Request

RRC

RRC

Assign RNTI, L1, L2 Parameter

RRC

AAL2 Setup and FP synchronization

RRC Connection Setup

RRCRRC Connection Setup Complete

RRC setup procedure


RRC setup success ratio Possible failure causes:

UE does not receive the RRC setup message from RNC

RNC does not receive the RRC setup complete message

RRC rejected due to congestion


RAB Establishment KPI

We have got two KPI with respect RAB Establishment for different scenario like

speech,CS64,PS interactive & PS streaming,

RAB attempts

RAB Establishment success rate

RAB Attempts:

Measurement point: received numbers of RABs to be setup for service “X” in message

RANAP RAB ASSIGNMENT REQUEST.

RAB Establishment Success Rate:

− Measurement point: the numbers of successful RABs setup for service “X”

in message RANAP RAB ASSIGNMENT RESPONSE

Service type:

− Conversional, streaming, interactive, background



UE SRNCNodeB CN

RANAP RANAPRAB Assignment Request

ALCAP Iu Data Transport Bearer Setup

RRCRRC

RRC

RB Setup

RRCRB Setup Complete

RANAP RANAPRAB Assignment Response

NBAP RRCRL Reconfig Prepare

NBAP NBAP

NBAP NBAP

ALCAP Iub Data Transport Bearer Setup

RL Reconfig Ready

RL Reconfig Commit

RAB setup procedure （ DCH-DCH, synchronized ）



Formula :

RAB Setup success rate (Service “X”) = RAB Setup success(Service

“X”)/RAB Setup attempts Service “X”)

Service “X” can be of different Qos & service rate namely

Conversational( Voice & video)

Streaming services with rates of 32K,64K,144K,384K

interactive services with rate of 32K,64K,144K,384K

Background services with rates of 32K,64K,144K,384K

HSDPA & HSUPA.


RAB setup success ratio Possible failure causes:

CN send RAB assignment req, but UE does not receive RB setup

message (due to congestion, high BLER, etc)

UE recieves RB Setup but RNC does not receive RB setup

complete

Resource unavailable


Accessibility

Call drop

Congestion

Handover

Traffic erlang / throughput


Call drop rate & Retainability KPI

Definition:

Call drop ratio = A/(A+B)

A= Number RAB released Abnormally

B = Number of RAB released Normally

Retainability of “X” service = (1- call drop ratio of “X” service)*100

Speech minutes per drop =GP in minute *Erl_Speech/Number of RAB released

abnormally


Call drop analysis procedureNormal RAB Release scenario’s

Generally the release of RAB or Iu is triggered by CN,However in the following conditions the RNC triggers the RAB or Iu release,

RNC may trigger RAB release after “PS inactive detecting timer” expires

RNC may trigger Iu release after an inter RNC handover

UE request RNC to release RRC,then RNC may trigger Iu release (Blackberry UE)

Abnormal RAB Release Procedure can subdivided into

RF reasons

Non RF reason

RF Reason:

If RNC send Iu release request message with release cause “Radio connection with UE lost” or Failure in the Radio interface procedure”

Non RF reason:

If RNC sends Iu release request message with cause value of “abnormal release” which could have happened due AAL2 link failure or Iu link failure or abnormal UE


Signaling plane call drop

SRNC CN

RANAP RANAP

RANAP RANAP

RANAP RANAP

Iu Release Request

Iu Release Command

Iu Release Complete

Signaling procedure


Signaling plane call drop

Possible causes for Iu Release Request message:

O&M interfere

User inactivity

Integrity protection failure

Radio link failure


User plane call drop

UE SRNC CN

RANAP

RANAP RANAP

SRNC Identities that the RAB need to be released

RANAPRANAP

RRC

RANAP

RAB Release Request

Iu Release Command

ALCAP Iu Bearer Release

RANAP Iu Release Complete

RRC

RRC RRC

RRC Connection Release

RRC Connection Release Complete

Signaling procedure:


User plane call drop

Possible causes:

L2 resource abnormal, (e.g.: DSP failure)

Transport resource unavailable

RLC reset due to bad radio link

RL failure


Accessibility

Call drop

Congestion

Mobility



SHO success ratio

Definition:

A ： Numbers of ActiveSet Update Complete message

RNC received

B ： Number of ActiveSet Update Command RNC send

%100B

AerSuccRateSoftHandov


SHO success ratio

UE New NodeB SRNC

NBAP NBAP

Decide to setup new RL


NBAP NBAP

RRC RRC

RRCRRC DCCH : Active Set Update Complete

Radio Link Addition Request

DCCH : Active Set Update Command

Radio Link Addition Response


SHO success ratio

UE New NodeB SRNC

NBAP NBAP

Decide to setup new RL


NBAP NBAP

RRC RRC

RRCRRC DCCH : Active Set Update Failure

Radio Link Addition Request

DCCH : Active Set Update Command

Radio Link Addition Response

Failure procedure


SHO success ratio

Possible causes of SHO failure:

Active set update failure: ：

− UE does not receive Active set update message

− UE does not send Active set update complete message

− RNC does not receive Active set update complete message

− RNC received Active set update failure


HHO success ratio

Definition:

A ： successful HHO

B ： total numbers of HHO

%100B

AerSuccRateHardHandov


HHO success ratio

UE Target NodeBSource NodeB SRNC

Decide to handover

RRC

NBAPNBAP Radio Link Setup Request


NBAP NBAPRadio Link Setup Reponse

RRCDCCH : Physical Channel Reconfiguration

NBAPNBAP Radio Link Failure Indication

RRC RRCDCCH : Physical Channel Reconfiguration Complete

NBAP NBAPRadio Link Deletion Request

NBAP NBAPRadio Link Delete Response

ALCAP Iub Data Transport Bearer Release

Successful procedure


HHO success ratio

UETarget NodeB

(Incoming the Cell)Source NodeB

(Outgoing the Cell)

SRNC

Decide to handover

RRC

NBAPNBAP Radio Link Setup Request


NBAP NBAPRadio Link Setup Reponse

RRCDCCH : Physical Channel Reconfiguration

NBAPNBAP Radio Link Failure Indication

RRC RRCDCCH : Physical Channel Reconfiguration Failure

NBAP NBAPRadio Link Deletion Request

NBAP NBAPRadio Link Delete Response

ALCAP Iub Data Transport Bearer Release

failure procedure


Accessibility

Call drop

Congestion

Handover



CS Traffic

CS traffic is measured in Erlang （ one12.2k CS AMR connection in one

hour is one erlang), other service should change to equivalent AMR

erlangs

CS service has 2 types:

CS conversational (for example: voice and video)

CS streaming (for example ： streaming video /audio)


PS data throughput

We got traffic statistics indexes in our OSS reports for

Data volume for R99 services in DL & UL

HSDPA services

Services Throughput for R99 in DL & UL

HSDPA & HSUPA Services throughput


Thank you

UMTS Statistics KPI Training

Documents

performance measurement

measurement procedures

measurement jobs

network wide kpis

transport performance

setup calls

gpp tr

gpp ts3gpp