3G QoS Management TUT Lecture 19.10 QoS Management Lecture.pdf · • Reliable user service flow identification required. ... • Call set-up time requirements. ... 3G QoS Management

3G QoS ManagementTUT Lecture19.10.2006

Eero WalleniusNokia OS/NSB

1 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

Goals of the lecture

End-to-end IP Service Quality and Mobility- Lecture #1 -

• Give basic information on:• Standardization• What is Qos by definition IP QoS• Operators and services


Who’s who in standards

• Internet Engineering Task Force (IETF)• Standardization of Internet protocols, such as TCP, UDP, SCTP,

RTP, SIP, …• Does not standardize architectures.

• ETSI/Third Generation Partnership Project (3GPP)• Standardization of 3rd generation mobile networks, including

architectures and QoS models.

• ETSI/TIPHON• Originally IP telephony related standardization, including

architecture and QoS model.

• ITU-T• Extending towards Internet technologies.


Service quality

• Term “Quality of Service (QoS)” is not well-defined.• Terms used in this lecture:

• End-to-end service quality: the result that the user of the service can observe.

• Affected by all links in the end-to-end service delivery chain.• Also affected by psychological factors (e.g., use situation).

• Service quality support mechanisms: the means of providing controlled end-to-end service quality

• End-to-end service quality is a result of service quality support mechanisms used by different parties.

• Typically devices such as Service Level Agreements (SLAs) need to be used to provide end-to-end service quality.


Service quality, cont’d

GPRS access

WCDMA access

(Mobile) IP access

TransitTerminal

Services

SLA

SLA

SLA

SLA

SLA

SLA

SLAUser

Access Backbone Service domain

End-to-end service quality

Per-userSLA

AggregateSLA


ServiceProviderspecificSLA

Multi-technology access to IP services

•IP in the endpoint.•IP-based services.

•SIP as an enabler.•Access technologies support end-to-end IP:

•Cellular & ADSL: tunnelled IP.•Fibre access: pure IP routing.•WLAN + mobile IP: IP-based mobility.


Some notes about IP-based services• In IP environment like IMS, service creation is more flexible than

in Intelligent Networks environment of POTS.• SIP provides means for subscriber availability and capability

information exchange.• Provides building blocks for Virtual Home Environment (VHE)

across technology boundaries & terminals.• Carrier-class features need to be implemented for certain IP

services such as telephony: high availability, reliable and understandable charging, security, …

• 3GPP R5: IP Multimedia Subsystem (IMS)• Generally, services to which end user subscribes (pays), require

better support.


About service providers• Service providers can have

two kinds of roles: providers of content services or connectivity services.

• Content services:• HTML, streaming, E-

commerce, animation of kittens singing Led Zeppelin.

• Connectivity services:• (Multimedia) telephony• Instant messaging• Presence

Serviceprovider

Accessprovider

ClientServer

Serviceprovider

ClientClient

Connectivityprovider

Server

EnduserSLA

EnduserSLA

EnduserSLA

Inter-provider SLA

Inter-provider SLA


Roles of operators

• Traditionally, POTS operators have provisioned both the access and the services.

• Recent trend has been towards technologies allowing decoupling of services from access.

• Service operators• Provide services• For connectivity-type services such as VoIP, interface to peer

service operators.

• Access network operators provide access to Internet.• Take into account service specific requirements

• Transport operators provide transit network connectivity.


Services

• Services can be provided:• On subscription basis (either to a service or set of services).• Based on request from end user or other service provider.• Free of charge.

• When charging involved:• Reliable user service flow identification required.• It shall be possible to either ask for per-instantiation service quality

support explicitly or provide necessary service quality support “implicitly” based on SLAs.

• SLAs may be used towards peer service providers, network operators, and end users.

• Per-session service quality signalling can still take place.


Endpoints

• Endpoint instantiates the service• E.g., SIP, RTSP, HTTP, WAP.

• Endpoint may indicate its own capabilities• E.g., SDP: VoIP codecs available.• Alternative: network deduces terminal capabilities indirectly.

• Endpoint may request service quality support instantiation• E.g., RSVP, PDP context activation signalling.• Alternative: SQS type deduced indirectly

• Defined in subscription.• Defined in SLAs towards service providers.• …


Role of the endpoint

• In multi-access network, the endpoint capabilities vary.• PC-type endpoint:

• Lots of processing power, large memory.• Large display, stereo speakers.• Keyboard & mouse available.

• PDA/cellular phone –type endpoint:• More limited processing power & memory.• Display smaller, sound capabilities limited.• Input devices more constrained.

• Conclusion: preferably service instantiation dependent on the type of endpoint.


Role of access technology

• Access technology has an effect on services:• Available bandwidth.• RTT, delay variation, packet loss.• Service availability.• Service instantiation time varies.• Service quality support mechanisms vary per access technology.

• Service quality support mechanisms available.• Access network may not be able to provide support for real-time services.• There may be no guarantees.

• Mobility support varies.


Case VoIP media stream

• VoIP with 8 kHz PCM coding, 8 bit sample resolution• Bi-directional• “On/off” traffic pattern, talkspurts & silence periods• 20 ms frame size => 160 bytes / sample• 1 sample / packet⇒During talkspurts, a 200-byte packet is transmitted every 20 ms

(IPv4); during silence periods no packets (VAD).⇒Requires 80 kbit/s IP layer throughput


Case HTTP browsing

• HTTP browsing without pipelining.• Request / response pattern.• HTTP GET requests typically small, HTML page sizes vary.• Large non-textual objects such as can be embedded into HTML

pages.• User wants interactivity: something happens “soon” when a

hyperlink is clicked.• Non-first time users understand that downloading large content

takes time.• It is the total downloading time that counts

⇒Small messages best given some statistical capacity in “uplink” direction, downlink can vary more.


Mobile applications

• Off-line data transfer (e-mail)• On-line data transfer• Browsing• Messaging• Presence• Chat• Games• Streaming• Multimedia-over-IP conferencing


Data transfer

• Examples: e-mail, downloading of a picture, a piece of music or a game.

• Characteristics:• Content size can be large.• E-mail: more or less symmetric, downloading:

unidirectional/asymmetric.• Irregular arrival process for service events.• Traffic can be bursty.• Applications typically very elastic with respect to utility.• TCP-based.

• Conclusion:• Bandwidth designed


Interactive applications

• Examples: browsing, M-commerce.• Characteristics:

• Content size varies.• Symmetric to asymmetric bandwidth characteristics.

• Some services have real service instances.• Arrival process for service instances random.• Arrival process for service events also random, but may be frequent.• Request and response temporally close to each other.

• TCP-based.

• Conclusion: sufficient r & B for most HTTP/WAP requests, downlink throughput can be designed.


Simple SIP services

• Examples: (instant) messaging, chat/presence.• Characteristics:

• Content size varies.• Can be unidirectional, symmetric, or asymmetric.• Arrival process random for service instances and service events.

• Some degree of interactivity expected of IM, chat.

• TCP or UDP based.

• Conclusion:• Sufficient throughput for small messages, throughput for large

messages may be designed.• UDP: shaping rather than dropping.


Streaming

• Examples: audio or video streaming.• Characteristics:

• RTSP signalling:• Interactivity.• TCP or UDP.

• Media flow:• Periodic PDU stream.• Can be bursty or already shaped.• UDP, for firewall traversal reasons also TCP.

• Conclusion:• Need to provide enough bandwidth, but can apply shaping to media

flow.


Multimedia conferencing

• Examples: audio or video conferencing.• Characteristics:

• SIP signalling:• Call set-up time requirements.• TCP or UDP.

• Media flow:• Periodic PDU stream.• Can be bursty (video).• UDP.

• Conclusion:• Need to provide enough bandwidth for media stream & signalling.


End-To-End Service Quality


Scenario #1: G.711 VoIP telephony

• Service availability and continuity must be sufficiently high.• Call set-up time must be sufficiently short.• Telephony interactive => end-to-end delay must be < 400 ms,

preferably < 250 ms [Y.1541,101329-2].• Delay variation compensation is part of the end-to-end delay budget.

• Sufficient token rate needed for media stream.• No error concealment in codec => packet loss percentage must be

small.• Dejittering buffer may give rise to effective packet loss.• Packet loss should not be too correlated.


Scenario #2: browsing

• Availability, continuity.• Users tend to build preferences towards sites (bookmarked).• Availability and continuity important especially for portals.

• Browsing must be interactive.• Reaction to clicking a link should follow promptly.• It’s the total downloading time that counts =>

• Throughput for large downlink content engineered.

• HTTP run on top of TCP• TCP throughput considerations need to be taken into account.


E2e service quality characteristics

• Aggregate level characteristics:• Availability.

• Service instance level characteristics:• Continuity.• Service instantiation time. • Throughput consistency.

• Service event level characteristics:• E2e latency.• E2e event loss.• (BER).

• Note: TSpec parameters are part of service event characteristics!


Availability• Availability is measured on aggregate service level as per cents of

total time.• Depending on service, availability may be defined in different ways:

• All service events belonging to the service instance must be present.• Some service events may be optional.

• Example: ACME kryptonite detectors• Seeing marketing video considered essential for service event, ditto for

other service events.• Availability = 100% - (V||P||C)

• V = video unavailability• P = payment unavailability• C= confirmation unavailability


Latency


3 (WIDEBAND)

2 (NARROWBAND) 1 (BEST EFFORT)

2H (HIGH)

2M (MEDIUM)

2A (ACCEPTABL

E)End-to-end

Delay< 100 ms

< 100 ms

< 150 ms

< 400 ms

< 400 ms

NOTE: The delay for best effort class is a target value.

• Inherent latency requirements:• PDUs of IP media streams of conferencing applications.

• Designed latency:• Interactive IP control traffic (RTSP, SIP, HTTP GET, WAP).

• Designed throughput:• Data traffic (FTP, HTML).

Event loss

• Overall effect of event loss depends on L4 and L2 protocol.• TCP: retransmissions hidden from application up to maximum retry

limit.• UDP: IP-level packet losses visible to end application.• L2 reliability.

• Loss can also take place because of bit errors (cf. next slide).• PDU loss usually degrades service quality of all services.• For media streams, correlated packet loss degrades end user

experienced quality even with loss concealment schemes.• VoIP: lower audio quality.• Packet video: skipped / distorted frames.


BER

• Bit Error Rate (BER) most important for wireless links.• UDP: checksum computed over header & data.

• If checksum does not match one computed from L4 SDU, datagram rejected.

• RT data on wireless links: checking of headers needed, retransmissions not good for end-to-end latency.

• Higher bits of audio samples are more important than lower bits.• UDPLite: checksum covers header + predefined number of the

highest bits of payload.


Throughput consistency

• Minimum token rate required by media streams of real-time IP applications:

• IP telephony.• Streaming.

• Throughput consistency also yields higher overall throughput forTCP-based data transfer.

• For long data transfers, overall throughput most important => effect of individual bursts of lower throughput.


Estimates for end user experience (eQoS)

• End user experience of service quality can be estimated:• With measurements.• Via modelling.

• Measurements:• Mean Opinion Score (MOS) for telephony [P.800].

• Modelling:• Transmission planning: E-model [G.109].• Cognitive modelling: PESQ [P.862] etc.

• Can be generalized to other services apart from voice?


Overall Transmission Quality Rating

90 £ R < 100 80 £ R < 90 70 £ R < 80 60 £ R < 70 50 £ R < 60

User's satisfaction

Very satisfied Satisfied Some users dissatisfied

Many users dissatisfied

Nearly all users dissatisfied

Data transfer

• Desirable end user experience:• Availability designed.• Data transfer commences quickly.• Overall duration predictable.

• Conclusions:• Designed delay for small messages in UL direction.• Downlink:

• Designed delay, relatively consistent.• Throughput relatively consistent.• Packet loss designed, relatively consistent.


Interactive applications

• Desirable end user experience:• Availability relatively high (designed).• Replies to requests take place interactively.• Duration for downloading predictable.

• Conclusions:• Availability needs special attention.• Designed delay for small messages in UL direction.• Downlink:

• Designed delay, relatively consistent.• Throughput relatively consistent.• Packet loss designed, relatively consistent.


Simple SIP services

• Desirable end user experience:• Availability high.• Service instantiation relatively fast.• Some service events must have relatively low latency.

• Conclusions:• Availability needs special attention.• Designed delay and loss performance for small messages.• For large content (e.g. pictures), as with downloading.


Streaming• Desirable end user experience:

• Availability high.• Service instantiation interactive.• Media quality high (more important for audio than for video).

• Conclusions:• Availability needs special attention.• Designed delay and loss performance for RTSP.• Latency for media streams relatively small.• Constant token rate desirable

• Packet loss allowed if retransmissions possible.• BER may be allowable for media streams.


Multimedia conferencing

• Desirable end user experience:• Availability high.• Service instantiation quick.• Media quality high (more important for audio than for video).

• Conclusions:• Availability needs special attention.• High delay and loss performance for SIP signalling.• Latency for media streams small.• Minimum token rate required for audio component, desirable for

video component.• BER allowable for media streams.


Summary

• Service quality requirements: service type inherent vs. end userexperience related.

• Most important service quality characteristics:• Availability.• Service instantiation time. • Throughput consistency.• E2e latency.• E2e event loss.• (BER).

• Temporal correlations.• Modelling of end user experience.


End-to-end IP Service Quality and Mobility


Mobility-related concepts

• Nomadicity = ability to connect to network in different locations.• Also known as portability.

• Mobility = ability to maintain sessions• While moving physically.• While switching between access technologies.

• An IP address has two roles for an endpoint:• Identification of an endpoint for socket connection.• Identification for a route to the endpoint

• When the endpoint supports mobility, separate addresses may be needed for these purposes.


Mobility-related concepts, cont’d

• Reachability address• Address via which the endpoint can be reached.

• Point of Attachment (PoA):• Routing address for the endpoint.

• Examples:• GPRS/3G:

• Endpoint receives its IP address from gateway.• IP reachability address = IP-level PoA.

• GPRS-level PoA invisible to end application.

• Mobile IP:• Endpoint receives its IP address from access router.• Reachability address != PoA if away from home link.


Scenarios

• Assumption: service instance can be maintained during mobility.

• Scenario #1: Britney is walking downtown Helsinki and using WAP with her GPRS terminal to access the home page of her favourite rock group.

• End user service quality level is negotiated between the terminal and the GPRS network.

• Mobility management is handled beneath the end user IP layer.

• IP address stays the same.• QoS control on GPRS layer.


Scenarios, cont’d

• Scenario #2: Britney is walking about Helsinki with a laptop equipped with a 802.11 PCMCIA card, every now and then stopping in a café and browsing the Internet.

• End user service quality provisioned by the operator.• Service quality more directly coupled to user IP layer.• If session needs not be maintained between browsing sessions,

may be implemented within the category of nomadicity.• Operator needs to take into account service quality consistency.

• If session continuity needed, MIPv4 or MIPv6 can be used.• Handover performance needs to be considered.


Scenarios, cont’d

• Scenario #3: Britney is sitting in a car downtown Helsinki with a laptop sporting WCDMA/802.11 PCMCIA card, watching streamed video.

• WLAN used in hotspots, WCDMA outside them.• End user service quality provisioned by the operators.• Available bandwidth can be larger in WLAN hotspots (up to 11

Mbit/s).• Service quality needs to be consistent between access

technologies.• Handover between access technologies should be as seamless as

possible.• Authentication.


Service quality challenges

• Reachability challenge: how to locate an endpoint?• L1 answer: 21000 km long RJ45 cable ☺.• L2 answer: GPRS / 3G + roaming agreements.• L3 answer: MIPv4 / MIPv6.• L4 answer: SIP.

• Mobility between PoAs (L2 or L3).• Continuity, service instantiation time, service event level

performance.

• Mobility between access technologies.• Continuity, service instantiation time, service event level

performance, reachability.


Ad hoc networks

• Ad hoc networks do not have predefined infrastructure.• Mobile nodes fixed but topology not constrained.

• E.g., “wireless routers” on 2.4GHz band.

• Network nodes may be moving.• E.g., 802.11 clients in infrastructure-less mode.

• Challenges:• Topology variable.

• Large share of overall traffic may need to be routed over small number of nodes.

• Routing updates.

• Service quality support mechanisms need to be adaptive.• QoS model.


Service quality control for mobility

• Topological diversity.• Use multiple PoAs simultaneously.• “Make before break”.

• End-to-end service quality downgrading / renegotiation.• Guaranteed performance vs. shared capacity.• Can also be implicit – different kinds of end user SLAs for different

technologies.

• Interrupted communication.• Shift service instance / event in time.

• Connection blocking/dropping.• Continuity/availability may be standardized or defined in end user

SLAs.


GPRS QoS


Why GPRS? End user viewpoint

• Example 1: WAP connection using GSM data.• Connection set-up slow – up to 25 seconds.• User pays for the connection time.• For most of the time, little data is transferred.• When WAP session is “on”, no calls can be received.

• Example 2: WAP connection using GPRS.• Connection set-up typically a couple of seconds.• User typically pays either flat rate or for the amount of data

transferred.• Connection can be “on” for hours.• Calls can be received during WAP sessions (class A or class B

terminals).


Architecture


POTS

OtherGPRS

domain

GRE

IPdomain

OtherPLMN

BSCBTS

UE

MSC GMSC

HLR

GGSN

SGSN

Main architectural elements

• MS: can activate GPRS sessions.• BSC: can interface towards SGSN for packet data.• SGSN: handles terminal mobility and authentication, radio and

GPRS QoS, temporary storage of subscription data.• GGSN: “edge router” for GPRS, IP address allocation, GPRS

QoS.• HLR: permanent storage of subscription data (including QoS

profiles).• BG: interfacing to other PLMNs.


Mobile station

• MS types:• Phone + GPRS enhancements.• “PDA phone”.• Laptop PC + GPRS MT.• Dedicated GPRS MT.

• Terminal types:• Class A: can use GPRS and GSM services simultaneously.• Class B: can use either GPRS or GSM an any given time, can

interrupt GPRS for an incoming GSM call.• Class C: GPRS only.


Mobility

• When MS wants to use GPRS services, it performs GPRS attach.

• Terminal must initiate a PDP context once attached.• Location updates sent to network when changing cells.

• Standby state (not active): granularity of RA.• Active state: granularity of cell.

• MS stops using GPRS services using GPRS detach.• SGSN tracks user at the granularity of a cell for active

sessions, RA for standby state terminals.• GGSN tracks user at the granularity of a SGSN.


PDP contexts

• A PDP context is needed to send or receive packet data.• Properties of a PDP context:

• Addressing is defined per PDP context (IP assumed in what follows, both IPv4 and IPv6 supported).

• PDP context terminates at an Access Point Name (APN) in GGSN, defining the interfacing point to extra-PLMN networks.

• QoS is negotiated per PDP context.

• A MS may support one or more simultaneous PDP contexts.• PDP context expires after certain time if no data have been sent.


GPRS R99 QoS profile

• GPRS R99: subset of “full” 3GPP QoS profile for GPRS.• Allocation/retention priority (ARP).• Traffic class + traffic handling priority (THP).

• Interactive: THP1-3.• Background.

• Reliability parameters:• residual BER• SDU error ratio• delivery of erroneous SDUs.

• Maximum bit rate.

• Can differentiate between BE and interactive services, implementprioritisation also in radio interface.


Core network QoS

• Transport between SGSN and GGSN: user data GTP tunnelled over UDP/IP.

• Core network IP QoS can be provided by provisioning + mapping of GPRS QoS to IP QoS based on QoS profile data.

• Mapping performed by SGSN (uplink) and GGSN (downlink).• Example: standard DiffServ.

• Interactive THP1 -> AF21.• Interactive THP2 -> AF22.• Interactive THP3 -> AF23.• Background -> AF33.


Summary

• GPRS uses GSM radio infrastructure.• Architectural support for bursty packet based data.• Basic GPRS does not support RT services.• QoS defined per PDP context.

• Terminal-initiated PDP context activation / deactivation / modification.

• Network can terminate or modify PDP context.

• Supports data downloading and interactive type applications.• GSM evolution radio interface GERAN also exists for UMTS =>

next lecture.


3G QoS ManagementTUT Lecture20.10.2005

Eero WalleniusNokia OS/Network Operability System Design (NOSD)


3GPP standard releases

• R99• UTRAN: WCDMA

• R4• IP transport extension

• R5: • GERAN Iu mode• IMS support

• R6:• WLAN interworking

• R7: • TBD


3GPP design philosophy

• Targets:• Multi-service support also for RT services

• Delay• Reliability

• High spectral efficiency

• UTRA: UE and RAN redesigned• Can interface both to “GSM-like” Circuit Swithed (CS) and Packet

Switched (PS) core networks.

• End user services are supported using bearers, the properties ofwhich are negotiated with the network.

• Connection set-up• During connection

• Hide as much of mobility from Core network (CN) as possible.


User perspective

• Envisioned end user service types on 3rd generation schedule:• Conferencing (includes telephony)

• Voice conferencing• Video conferencing

• Streamed content• Audio• Video

• Interactive applications• Web browsing• Network games

• Background• Background downloading



UMTS network architecture

UTRAN CN

OtherGPRS

domain

GRE

IPdomain

OtherPLMN

RNCNobe B

UE

MSC GMSC

HLR

GGSN

SGSN

Call & Subscriber control

User Plane

Rôles of network elements in UMTS

• UE: capable of managing PDP contexts.• Node B: convert data between radio interface (Uu) and UTRAN

(Iub); participate to radio resource management.• RNC: manage radio resources and handovers, act as a service

access point towards CN for all UTRAN services, QoS.• SGSN: handles terminal mobility and authentication, radio and

GPRS QoS, temporary storage of subscription data.• GGSN: “edge router” for GPRS, IP address allocation, GPRS

QoS. • HLR: stores subscriber data, including QoS profile.


UMTS bearers

• UMTS bearer service defines service performance between UE and GGSN.

• UMTS bearer is requested by UE.

• UMTS bearer makes use of bearers beneath it.

• Bearer mapping is not standardized.

TE MT UTRAN CN IuEDGENODE

CNGateway

TE

UMTS

End-to-End Service

TE/MT LocalBearer Service

UMTS Bearer Service External BearerService

UMTS Bearer Service

Radio Access Bearer Service CN BearerService

BackboneBearer Service

Iu BearerService

Radio BearerService

UTRAFDD/TDD

Service

PhysicalBearer Service


Design principles of 3GPP QoS

• Derivation of QoS attributes from application requirements shallbe simple.

• QoS definitions shall be future proof.• QoS has to be provided end-to-end.• QoS mechanism have to allow efficient use of radio capacity.• Allow evolution of UMTS network.

• Allow for independent evolution of core and access networks.

• UMTS shall provide for session-based QoS with possibility for asymmetric bearers on peer-to-peer basis between UE and gateway node.


3GPP QoS profile• Traffic class ('conversational', 'streaming', 'interactive', 'background')• Maximum bit rate (kbps)• Guaranteed bit rate (kbps)• Delivery order (y/n)• Maximum SDU size (octets)• SDU format information (bits)• SDU error ratio• Residual bit error ratio• Delivery of erroneous SDUs (y/n/-)• Transfer delay (ms)• Traffic handling priority• Allocation/Retention Priority• Source statistics descriptor (‘speech’/’unknown’)


Value ranges for UMTS bearer


Traffic class Conversational class Streaming class Interactive class Background class

Maximum bitrate (kbps) < 2 048 (1) (2) < 2 048 (1) (2) < 2 048 - overhead (2) (3) < 2 048 - overhead (2) (3)

Delivery order Yes/No Yes/No Yes/No Yes/No

Maximum SDU size (octets) <=1 500 or 1 502 (4) <=1 500 or 1 502 (4) <=1 500 or 1 502 (4) <=1 500 or 1 502 (4)

SDU format information (5) (5)

Delivery of erroneous SDUs Yes/No/- (6) Yes/No/- (6) Yes/No/- (6) Yes/No/- (6)

Residual BER 5*10-2, 10-2, 5*10-3, 10-3, 10-4, 10-5, 10-6

5*10-2, 10-2, 5*10-3, 10-3, 10-4, 10-5, 10-6

4*10-3, 10-5, 6*10-8 (7) 4*10-3, 10-5, 6*10-8 (7)

SDU error ratio 10-2, 7*10-3, 10-3, 10-4, 10-5 10-1, 10-2, 7*10-3, 10-3, 10-4, 10-5

10-3, 10-4, 10-6 10-3, 10-4, 10-6

Transfer delay (ms) 100 – maximum value 250 – maximum value

Guaranteed bit rate (kbps) < 2 048 (1) (2) < 2 048 (1) (2)

Traffic handling priority 1,2,3

Allocation/Retention priority 1,2,3 1,2,3 1,2,3 1,2,3

Source statistic descriptor Speech/unknown Speech/unknown

UMTS QoS details

• Air interface QoS controlled by Radio Resource Management• Admission control• Power control• Code management• Packet scheduling• Handover control

• In 3GPP R4, IP transport can extend up to RNC.• IP transport bearers can be managed with same principles as in

GPRS.• Interworking towards external networks as with GPRS.• R5: linking of SIP session QoS to 3GPP QoS possible.


3GPP QoS management functions

Transl. Transl.

Adm.Contr

RABManager

UMTS BSManager

UMTS BSManager

UMTS BSManager

Subscr.Control

Adm./Cap.Control

MT GatewayCN EDGEUTRAN

Ext.ServiceControl

LocalServiceControl

Iu BSManager

Radio BSManager

Iu NSManager

UTRAph. BS M

Radio BSManager

UTRAph. BS M

Local BSManager

Adm./Cap.Control

Adm./Cap.Control

Adm./Cap.Control

Iu BSManager

Iu NSManager

CN BSManager

Ext. BSManager

CN BSManager

service primitive interface

BB NSManager

BB NSManager

protocol interface

TE Ext.Netw.

ResourceManager

Mapper

Classif

Cond.

ResourceManager

ResourceManager

Mapper

ResourceManager

Mapper

ResourceManager

ResourceManager

Cond.

Classif

Cond.

MT GatewayCN EDGEUTRAN

BB network serviceIu network serviceUTRA phys. BS

data flow with indication of direction

TE Ext.Netw.

Local BS External BS

Controllayer

Userlayer


IP Multimedia Subsystem• 3GPP R5 brings with it support for SIP services in IP Multimedia

Subsystem (IMS).• Call State Control Function (CSCF) = SIP proxy.• Service signalling between CSCF and UE takes place using SIP.• UE activates a suitable bearer for the SIP session.


UE

P-CSCF

Serving CSCF

Home Network

Home/ Visited Network

Service Platform

Gm

Mw

Summary

• 3G R99 is based on GPRS core network.• Radio interfaces: WCDMA, EDGE.• WCDMA Radio Access Network (RAN) handles more of the

mobility than in GPRS radio access network.• Enhanced service quality support for packet traffic compared to

GPRS.• Conversational class• Streaming class

• Secondary PDP context for better QoS differentiation.• R5 brings support for SIP services for IMS.


Service Quality Provisioning


Service quality provisioning

• Service-centric viewpoint: end-to-end service quality provisioned for instantiations of aggregate service.

• Transport network operator viewpoint: service quality support provisioned for traffic aggregates.

• Access network operator viewpoint: instantiate service quality support for service instances.

Access TransportService


Provisioning principles

• Optimal way of end-to-end provisioning depends on the service quality support capability of the access network.

• Case 1: access network can instantiate service quality support per session.

• Session specific SQS signalling.• Fine-grained admission control.• Support for mobility easier, SQS renegotiation.

• Case 2: non-session based service quality support.• Allocate service quality level based on user class, application type.• Effect of mobility on service quality level determined solely by the

network.


Provisioning principles, cont’d

• Access network:• Case 1: fine-grained Service Quality (SQ) levels in access

network, negotiated with MN.• Case 2: coarse-grained SQ levels in access network, less

constraints for e2e SQ.

• Interface to transport operator:• SLAs covering different traffic aggregates to different PoPs.• Traffic conditioning agreement at peering points.


SLAs

• SLA is a contract between customer and a provider.• Definition of agreed-upon service quality level.

• Preferably using technology-independent terminology.

• Definition of reporting.• Means of verifying service quality level.• Definition of procedures for exceptional situations.• Common language.• Business agreement:

• Terms of applicability.• Validity period.• Definition of liabilities.


SLA and DiffServ• SLA defines the forwarding service a customer should receive

across a DiffServ domain.• Traffic Conditioning Agreement (TCA) specifies the

conditioning of traffic arriving at the peering point. Service Level Specification (SLS) defines detailed parameters of a DiffServ SLA.

• Per-Domain Behaviour (PDB) definitions specify the expected performance domain-wide.

• Traffic Conditioning Specification (TCS) specifies individual parameters of a TCA.

• classifier rules• metering rules• related actions


Policy management example

• Policy Decision Point (PDP).

• Policy Enforcement Point (PEP).

• Protocol variants:• Common Open Policy

Service (COPS) for outsourced mode.

• COPS-PR for provisioning.

IP network

PEP

PEP

PEP

PDP

PR


Bandwidth brokers• Thus far, static inter-domain SLAs have been assumed.

• May still include multiple traffic aggregates.• Alternative: dynamic allocation of end-to-end SQ across domains.• Two basic schemes:

• Service domain(s) negotiate end-to-end SQ level and allocate it to transport domains.

• Bandwidth brokers (BBs) in different network domains negotiate end-to-end SQ allocation.

• Tasks of a bandwidth broker [RFC2638]:• Keep track of resource allocations• Configure edge treatment• Manage resource allocations to other domains


Summary• End-to-end provisioning alternatives:

• Static• Per-session SQS • Aggregate SQS (like DiffServ)

• Dynamic• Service level negotiation.• Transport level negotiation: bandwidth brokers.

• Future• WiMax, OFDM based wideband

• Adopted by Sprint US as the next generation 4G system

• In 3GPP LTE (Long Term Evolution) and SAE (System Architecture Evolution) projects are defining the way to next generation 4G system


Material

• For more information, the following books are useful:• D. Wisely, P. Eardley, and L. Burness: IP for 3G,

John Wiley & Sons, Chichester, England, 2002. • C.E. Perkins: Mobile IP – Design principles and

practices, Addison-Wesley, Reading, U.S.A, 1998.• H. Holma and A. Toskala: WCDMA for UMTS,

John Wiley & Sons, Chichester, England, 2000.• V. Räisänen: Implementing Service Quality in IP

Networks, John Wiley & Sons, Chichester, England, 2003.


3G QoS Management TUT Lecture 19.10 QoS Management Lecture.pdf · • Reliable user service flow identification required. ... • Call set-up time requirements. ... 3G QoS Management

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