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An Overview of 3GPP QoS. 3GPP S2 QoS Drafting Group Edited by Xiaobao Chen 24 January 2001. Outline. Overview of UMTS QoS Standards, Definitions and the Architecture UMTS QoS Signalling UMTS QoS Control UMTS QoS Policy Control Open Issues Summary. UMTS QoS Standards.
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An Overview of 3GPP QoS 3GPP S2 QoS Drafting Group Edited by Xiaobao Chen 24 January 2001
Outline • Overview of UMTS QoS Standards, Definitions and the Architecture • UMTS QoS Signalling • UMTS QoS Control • UMTS QoS Policy Control • Open Issues • Summary
UMTS QoS Standards • TS23.107: QoS Concept and Architecture (R 99, R4 & R5) • provides the framework for QoS in GPRS/UMTS for Release 99, Release 4 and Release 5) • covers the QoS in both CS & PS • CS QoS: based on the QoS related bearer definitions of GSM. • PS QoS: GPRS R99 QoS attributes shall be equivalent to UMTS QoS attributes ( the focus and details to follow)
UMTS QoS Standards • TS23.207: End-to-End QoS Concept and Architecture (R5) • provides a QoS Framework that complements TS23.107 • only applicable to GPRS/UMTS PS access services. • focus on end-to-end QoS provisioning • address • the IP Level QoS mechanisms • QoS interactions between GPRS/UMTS Level, IP Level and Application Level. • inter-working with IM Subsystem and PSTN
UMTS QoS Definitions • UMTS QoS: • Service Contract: between the Users and the Networks • QoS in Circuit Switched (CS) & Packet Switched Services (PS) • End-to-End Service: between peer Terminal Equipment (TE’s) • QoS Operations: Control Signalling, QoS Management and User Plane Transport. • UMTS QoS Classes: • Conversational: preserve time relation with conversational pattern • Streaming: preserve time relation with unidirectional pattern • Interactive: preserve payload content with request-response pattern • Background:preserve payload content without specific delay limit.
-2 -2 -3 5*10 , 10 , 5*10 , -3 -4 -5 -6 10 , 10 , 10 , 10 -1 -2 -3 -3 10 , 10 , 7*10 , 10 , -4 -5 UMTS QoS Attributes & Values Conversational Traffic class Streaming class Interactive class Background class class < 2 048 (1) (2) Maximum bit-rate (kbps) < 2 048 (1) (2) < 2 048 - overhead < 2 048 - overhead (2) (3) (2) (3) Delivery order Yes/No Yes/No Yes/No Yes/No Maximum SDU size <=1 500 or 1 502 <=1 500 or 1 502 <=1 500 or 1 502 <=1 500 or 1 502 (octets) SDU format information (5) (5) Delivery of erroneous Yes/No/- (6) Yes/No/- (6) Yes/No/- (6) Yes/No/- (6) SDUs -2 -2 -3 -3 -5 -8 -3 -5 -8 Residual BER 5*10 , 10 , 5*10 , 4*10 , 10 , 6*10 (7) 4*10 , 10 , 6*10 (7) -3 -4 -6 10 , 10 , 10 -2 -3 -3 -4 -3 -4 -6 -3 -4 -6 SDU error ratio 10 , 7*10 , 10 , 10 , 10 , 10 , 10 10 , 10 , 10 -5 10 10 , 10 Transfer delay (ms) 100 – max. value 250 – max. value Guaranteed bit rate < 2 048 (1) (2) < 2 048 (1) (2) (kbps) Traffic handling priority 1,2,3 (8) Allocation/Retention 1,2,3 (8) 1,2,3 (8) 1,2,3 (8) 1,2,3 (8) priority
UMTS CN MT UTRAN TE TE CN Iu Gateway EDGE NODE End-to-End Service TE/MT Local External Bearer UMTS Bearer Service Bearer Service Service CN Bearer Radio Access Bearer Service Service Radio Bearer Iu Bearer Backbone Service Service Bearer Service UTRA Physical FDD/TDD Bearer Service Service UMTS QoS Architecture UE
UMTS End-to-End QoS • TE/MT Local Bearer Service: • internal to UE, • outside the scope of UMTS Networks. • UMTS Bearer Service: • Radio Access Bearer (RAB): • Radio Bearer Service & Iu Bearer Service • provide confidential transport of signalling and user data between MT and the CN Iu Edge Node with QoS • The Core Network (CN) Bearer Service: • provide transport bearer via Backbone Bearer Service (layer2&1 up to operators) • for both signalling and user data between CN Iu Edge Node and the CN Gateway • inter-working with the external network. • The External Bearer Service: outside scope of UMTS networks
UE GGSN Remote Remote AP Host IP Bearer Service IP Bearer Remote Local Layer Host UE Remote Backbone IP GGSN Access Network Point UMTS Bearer Service Access SGSN Bearer Layer Gn /Gp ( E g. UMTS Bearer) Scope of PDP Context UMTS Bearer Service vs. IP Bearer Service
UMTS QoS Signalling • UMTS Bearer Service Level • PDP Context: Primary PDP Context/Secondary PDP Context • QoS IE: distinction between up-link/down-link QoS • QoS Negotiation/Re-negotiation: Primary/Secondary PDP Context Activation/Modification. • RAB Assignment and QoS Negotiation
IP QoS Signalling • IP Bearer Service Level • UE: optional use of RSVP • RAN/SGSN: transparent transport of RSVP messages • GGSN: optional use of RSVP • GGSN may relay or process and forward the RSVP messages. • GGSN may terminate the RSVP messages.
UMTS QoS Control • UMTS Bearer Service Level • PDP Context: • QoS negotiation during Activation • QoS re-negotiated during modification (MS or Network Initiated - RNC/RAB Release/SGSN/GGSN initiated. • TFT: (Traffic Flow Template) • enable GGSN to perform packet classification and policing for down-link data transfer. • DiffServ on Iu and Gn • DSCP’s: operator dependent.
UMTS QoS Control • UMTS Bearer Service Level
UMTS QoS Control • UMTS Bearer Service Level • Translation: • convert between external service signalling or other non-signalled QoS mechanisms and internal service primitives including the translation of the service attributes. • UMTS BS Manager: • signal between each other and via the translation function with external instances to establish or modify a UMTS bearer service. • interrogates its associated admission/capability control whether the network entity supports the specific requested service and whether the required resources are available. • (CN Edge) verifies with the subscription control the administrative rights for using the service.
UMTS QoS Control • UMTS Bearer Service Level • RAB Manager: • verifies with its admission/capability control whether the UTRAN supports the specific requested service and whether the required resources are available. • translates the RAB service attributes into radio bearer service and Iu bearer service attributes and requests the radio BS manager and the Iu BS manager to provide bearer services with the required attributes. • Radio, Iu and CN BS managers • manages and use services provided by lower layers (radio channels, cables, etc.)
UE GGSN Capability Optional Required DiffServ Edge Function Optional Optional RSVP/IntServ Optional Required (*) IP Policy Enforcement Point IP Bearer QoS Control • IP Bearer Service Level • IP BS Manager: • uses standard IP mechanisms to manage the IP bearer service. • Provision of the IP BS Manager is optional inUE • Provision of the IP BS Manager is required in the GGSN. • ( * Although the capability of IP policy enforcement is required within the GGSN, the conrol of IP policy through the GGSN is a network operators choice.
IP Bearer QoS Control • IP Bearer Service Level • Translation: • provides the interworking between the mechanisms and parameters used within the UMTS and the external IP bearer service, and interacts with the IP BS Manager. • IP Policy Control: • a Policy Decision Point for implementing restricted QoS resource access at the IP BS Level. • a Policy Enforcement Point at the GGSN based on the IP policy decisions.
Policy Control • At PDP Context Set-up the user shall have access to one of the following alternatives • Alternatives: • Basic GPRS IP connectivity service: • The bearer is established according to the user’s subscription, local operator’s IP bearer resource based policy, local operator´s admission control function and GPRS roaming agreements. In this case, IP bearer resource based local policy decisions may be applied to the bearer.
Policy Control • Alternatives: • Enhanced GPRS based services : • The bearer is used to support an enhanced application-layer service, such as IM. In this case, service-based local policy decisions (e.g., authorisation and gating of the bearer by a proxy CSCF) may be applied to the bearer.
Open Issues • IP Policy Framework and Policy Interfaces • UMTS Signalling Enhancement to support inter-working with IP Policy Control and IP BS Manager • Interaction with IMS • QoS for Signalling Bearer • Bearer Establishment for SIP Call
Open Issues • UMTS Independent QoS Signalling (e.g. RSVP signalling) • UMTS IP QoS Mapping • Delay Values • End-to-End QoS Scenarios • Inter-working with External Network • QoS Management • QoS Aspects of UE architecture (e.g MT-TE)
Summary • UMTS covers QoS for both CS and PS services • End-to-End QoS Targeted for Multimedia Services • Allow for efficient use and utilisation of radio and network resources. • Flexible/Dynamic QoS provisioning • Provide tools for Restricted QoS resource and Service access based on Policy control. • Layered QoS control and management at the UMTS BS Level, IP BS Level as well as the IP Multimedia Service/Application Levels. • More challenging work in progress.