3GPP "TSG Highlights" from Plenary #15
Long, boring, Standards Stuff
3GPP has providrd the following concise summary of the decisions and actions of the most recent 3GPP Technical Specification Group meetings following their 15th plenary meetings in Jeju-do, Korea, 5-14 March 2002.
3GPP has five TSGs:
- CN (Core Network)
- RAN (Radio Access Network)
- T (Terminals)
- SA (Services and Systems Aspects)
- GERAN (GSM EDGE Radio Access Network)
This summary reports on the first four of these, as GERAN meetings take place separately from the other TSGs.
But first, let's clarify a basic question: What's a Release?
Within 3GPP, a Release is a full set of technical specifications (and supporting documents) that define a mobile system. A mobile system can be constructed based on the set of all specifications that comprise a given Release. And a specific Release differs from the previous Release by having added functionality introduced as a result of ongoing standardization work.
In order to permit an effective project management of the work, the task is made up of Work Items, each usually resulting in a specification or some other document.
Three levels of Work Items are recognised.
The top level is a Feature: each feature can be considered as an optional extra, which can be added or not to a system as a function of market demand. Normally a feature embodies an improved service to the customer and/or increased revenue generation potential to the supplier.
The next level of Work Item a Building Block, several of which make up a Feature.
Building Blocks are composed of the lowest level, Work Tasks.
These "TSG Highlights" will mostly refer to Features.
Release '99 was frozen at the end of 1999, Release 4 was frozen in March 2000, and Release 5 is "functionally frozen" (i.e. the functionality defined by the specifications included in this Release is frozen) during the first half of 2002. Release 6 is expected to be functionally frozen around the middle of 2003.
TSG-T (Terminals)
TSG-T has completed most of its Release 5 work at its recent meeting (March 2002). Release 5 topics which are still being worked on are related to the Multimedia Message Service (MMS) and ISIM, the Subscriber Identity Module for the IP Multimedia System (IMS). Work on testing always follows the main specification task, and this is so for User Equipment (UE) testing, which is ongoing for Release 99 and Release 4.
MMS Release 5 is completed except the MM1 (MMS relay/server - MMS user agent) and MM7 (MMS relay/server - Value Added Service Provider) interfaces. The stage 3 specification of MM1 will be developed by the WAP Forum. During TSG-T#15, a discussion took place on possibilities to further improve co-operation between the 3GPP and the WAP Forum. Key items resolved for MMS Release 5 include address resolution/MNP, MM4 enhancements, MM7 stage 2, persistent storage, USIM aspects, MMS charging (seeking to provide a standardised solution rather than various proprietary ones), header mapping, detection of duplicate messages, terminal capability negotiation on MM1 (permitting the contend supplied to a terminal to be varied according to its capabilities), and addressing on MM1.
[Following the TSG-T meeting, TSG-SA approved two new service requirements for MMS Release 5, related to automatic bearer selection and charging.]
The work on Enhanced Messaging Service (EMS) Release 5 is completed. EMS Release 5 brings several enhancements to the Short Message Service (SMS) like extended colour pictures, extended animations, Vector Graphics, and Polyphonic Sound.
It was agreed that a Release 4 Universal Integrated Circuit Card (UICC) will support MMS functionality for Release 5 and onwards. This brings a benefit for the use case where a Release 4 USIM which supports MMS is plugged into a terminal with a Release 5 MMS User Agent which supports the USIM.
The work on Mobile Execution Environment (MExE) Enhancements Release 5 was completed. The Common Language Infrastructure (CLI) has been added as the new MExE Classmark 4, supporting applications and services written in a wide range of programming languages.
It was agreed to start a work item for a MExE Run-Time Independent Framework Feasibility Study. The aim is to conduct analysis of the existing MExE Security Framework, Capability Negotiation, Content Negotiation, and Service Management for effectiveness in building an efficient scheme that applies to a run-time-independent UE application environment. It was also agreed to have a work item on MExE enhancements for Release 6 which includes general enhancements, investigation of support for VHE, USAT, OSA, CAMEL, security enhancements, terminal management, service provisioning.
A specification on USIM Application Toolkit (USAT) Interpreter; Protocol and administration (Release 5) was approved. It defines the transmission protocol between USAT Interpreter and USAT Interpreter Gateway System, and structures to administer the Interpreter.
Testing
There has been considerable attention to testing matters. TSG-T decided to update the UE test cases to the March 2002 version of the Release 99 core specifications aiming to have the test cases ready by October 2002. TSG-T will in future always aim to base test specifications on the latest version of the core specifications.
Funding restrictions have meant that currently no Testing & Test Control Notation (TTCN) test case implementation of the GERAN to UTRAN handover test cases could be started. Thus, for the present, only UTRAN to GERAN handover will be testable with test equipment using 3GPP TTCN.
As a first step towards "application enabler testing", it was agreed to create a feasibility study on MExE testing.
Two new work items for test specifications were approved: Security Mechanisms for the (U)SIM application toolkit test specification to achieve service interoperability between smart cards, and the SIM API for Java-Test specification to achieve interoperable application support.
TSG-SA (Services & Systems Aspects)
Adaptive Multirate (AMR WB) codec - A reduction in the number of telephony-service modes from 9 to 4 was agreed to simplify implementations with no reduction in quality - specifications to be updated for TSG SA#16.
A feasibility study on 3GPP system to Wireless Local Area Network (WLAN) interworking (Release 6) was noted by TSG SA (TR 22.934 version 1.0.0). A related SA WG2 WI was agreed.
A feasibility study report on Priority Service (Release 6) was noted by TSG SA (TR 22.950 version 1.0.0).
A (Release 5) report on Service Requirements for UE Functionality Split was approved (TR 22.944) - The Release for this Feature was agreed to be targetted for Release 6.
IMS Local services was removed from the Release-5 IMS feature.
Release 5 functional content was agreed, with final decision on full content depending on the availability of completed specifications at TSG SA#16 (June 2002). For the content of Release 5, refer to document SP-020201.
Technical Specification TS 33.203 - Access Security for IP-Based Services - was approved (Release 5).
Technical Specification TS 33.210 - Network Domain Security; IP network layer security - was approved (Release 5). There was an open issue on IMS Security - In order to progress the work on this it was agreed to hold an informal vote in SA WG3 by e-mail after the meeting to decide upon which integrity protection mechanism to choose (two proponents are being developed in the IETF). This vote has resulted in the IPsec solution being selected.
3Gpp Long-Term Evolution (Beyond 'R6':
A ToR will be drafted and provided to TSG SA#16 for approval and an ad-hoc group will be formed to report to TSG SA meetings (It is expected that the first meeting of this ad-hoc group will take place during the TSG#17 meetings in September). An e-mail list has been set up for discussion of Long Term evolution. (SP-020122)
TSG-Ran (Radio Access Network)
The TSG agreed to include "Any time interrogation" functionality as a Release 4 feature. (This will provide not only information about the location of a terminal but also a record of when that location was noted).
TSG-RAN has finished most of its work on Release 5, including most of the High Speed Downlink Packet Access work.
The following work items were completed at the latest meeting and will be part of Release 5 (in addition to work items that had already been completed in earlier TSG-RAN meetings). The first two, in particular, are very important enabling technologies for the development of new capabilities and services:
- High Speed Downlink Packet Access (HSDPA) (Physical Layer; layer 2 and 3 aspects; Iub/Iur Protocol Aspects)
- IP Transport in UTRAN
- RAN work for Intra Domain Connection of RAN Nodes to Multiple CN Nodes ("Iu-flex")
- Enhancement on the DSCH hard split mode
- Several Work Tasks that form part of Radio Resource Management (RRM)
- Optimization for Iur and Iub:
-- Radio Link Timing Adjustment
-- Separation of resource reservation and radio link activation
-- Iur Common Transport Channel Efficiency Optimisation
-- Iur Neighbouring cell reporting Efficiency Optimisation
-- For 1.28 Mcps TDD (equivalent work items for 3.84 Mcps TDD exist in earlier Releases):
--- Node B synchronization
--- UE Positioning Enhancements
The following work items are nearing completion and are expected to be finalised in June, as part of Release 5:
- TDD (3.84 Mcps) Base Station Classification
- Base Station Classification for 1.28 Mcps TDD option
- Radio access bearer support enhancement
- Support of Site Selection Diversity Transmission in UTRAN
- High Speed Downlink Packet Access (HSDPA)
-- RF Radio Transmission/ Reception, System Performance Requirements and Conformance Testing
A feasibility study on "Mitigating the Effect of CPICH Interference at the UE" was finished and as a result a new work item was approved: "Improving Receiver Performance Requirements for the FDD UE" (planned completion date December 2002, as Release 6).
TSG-RAN has recognised that support was needed for shared UTRANs in connected mode (idle mode already being supported), and a new work item was approved: Shared Network support in connected Mode. This is a Release 5 feature with a planned completion date of September 2002 (but an intent to finish by June 2002).
Finally, a feasibility study (planned completion date December 2002) was approved: UE Antenna efficiency test methods and requirements.
TSG-CN (Core Network)
The March 2002 meeting of TSG-CN noted a continued improvement in the stability of specifications from Release 4 and earlier.
Considerable progress has been made on the IP Multimedia System (IMS), with several key specifications being approved and placed under Change Control:
- 3GPP TS 23.218 "IP Multimedia (IM) Session Handling IP Multimedia (IM) call mode"
- 3GPP TS 24.228 "Signalling flows for the IP multimedia call control based on SIP and SDP"
- 3GPP TS 24.229 "IP Multimedia Call Control Protocol based on SIP and SDP Stage 3"
3GPP works closely with the Internet Engineering Task Force (IETF) and, under the terms of an agreement (RFC 3113), uses some of the IETF output. TSG-CN has noted that the IETF work is progressing well, enabling references to IETF RFCs to be updated in specifications being frozen in TSG-CN and TSG-SA. Having these RFCs delivered so early by the IETF is seen as a great achievement. The drafts, previously referred to as bundles 0 and 1, are
- RFC 3261 SIP: Session Initiation Protocol
- RFC 3262 Reliability of Provisional Responses in SIP
- RFC 3263 SIP: Locating SIP Servers
- RFC 3264 An Offer/Answer Model with SDP
- RFC 3265 SIP-Specific Event Notification
- RFC 3266 Support for IPv6 in SDP
- RFC 3267 RTP payload format and file storage format for the Adaptive Multi-Rate (AMR) Adaptive Multi-Rate Wideband (AMR-WB) audio codecs
- RFC 3268 AES Ciphersuites for TLS
TSG-CN approved a new work item for the Sh interface, based on IETF protocol DIAMETER. The Sh interface is between the Home Subscriber Server (HSS) and the SIP Application Server (SIP-AS), and between the Home Subscriber Server (HSS) and the OSA Service Capability Server (OSA SCS). It may be used for example for transferring User Profile information, for obtaining the address of the S-CSCF that serves the subscriber or the implicitly registered public user identities. Targeted completion date for this work is June 2002.
A second proposed work item on the CN portions of "Multimedia Broadcast Multicast Services" (MBMS) was referred to CN1, CN3, and CN4 for review and endorsement. MBMS should allow users to select one of a number of broadcast/multicast information sources, and to share with other users the network resources used to deliver that information.
The following major TSG-CN Work Items were allocated to Releases 5 and 6:
Work Item (CN portion) Date Release
Call Control in IMS Jun 02 Release 5
Cx interface Jun 02 Release 5
Access Security for IMS Jun 02 Release 5
End-to-End QoS Jun 02 Release 5
Interworking - IMS <-> IP Mar 03 Release 6
Interworking - IMS <-> CS Dec 02 Release 5/6
OSA for IMS Jun 02 Release 5
CAMEL for IMS Jun 02 Release 5
CAMEL Phase 4 Jun 02 Release 5
OSA Enhancements Jun 02 Release 5
WB-AMR Jun 02 Release 5
Service Change-UDI FB Jun 02 Release 5
Security Enhancements Jun 02 Release 5
IuFlex
(intra domain connection) Mar 02 Release 5
SA#15 requested that CN consider splitting of the IMS to CS interworking WI into a deliverable in June (without the parameter mappings) and a deliverable in Rel 6 containing the mappings. Work progress will be reviewed in June and the contents of Release 5 will be reassessed.
IP CN Harmonization Workshop ( April 3-4, 2002) in Toronto, Canada.
The following conclusions and recommendations on 3GPP/3GPP2 IP core network harmonization held in April 2002.
Harmonization Goals:
It was agreed that the harmonization of 3GPP/3GPP2 IP Multimedia Core Networks is a worthwhile and achievable goal that should be pursued urgently by both Partnership Projects. The focus will be on those areas where synergies already exist. In particular it was agreed that priority will be given to harmonization in the areas of:
- OSA/PARLAY based service APIs
- IMS (Referring to the 3GPP IP Multimedia Subsystem and its equivalent in 3GPP2 MMD)
Given that considerable alignment has already occurred in the area of 3GPP and 3GPP2 IMS, it was further agreed that 3GPP and 3GPP2 should adopt:
- A single IMS reference model (at a high level of abstraction, to be extended as appropriate within the 3GPP or 3GPP2)
- Consistent terminology to describe common IMS functional entities
Furthermore, it was agreed that the 3GPP and 3GPP2 should work to ensure:
- Interoperability between the 3GPP IMS mobiles and 3GPP2 IMS mobiles (a 3GPP IMS mobile can set up a session with a 3GPP2 IMS mobile and vice-versa)
- Application level intersystem IMS roaming (given that the mobile supports the visited network’s access network and IP transport technology, a 3GPP IMS mobile should be able to roam into a 3GPP2 network and vice-versa)
Recommendations:
Various recommendations were adopted to ensure that duplication of work between the Partnership Projects should be avoided and that existing schedules (e.g., 3GPP Release 5) should not be negatively impacted. These recommendations include:
- Alignment of the 3GPP and 3GPP2 IMS and service aspects of their respective Reference Models.
- Use by 3GPP2 of the 3GPP Release 5 IMS and Parlay 3.1 as the base for their on-going development activities.
- Continued collaboration between 3GPP and 3GPP2 and with other groups (IETF, ITU, etc.), supported by efficient working methods, both formal and informal (e.g. joint e–mail exploder).
3GPP and 3GPP2 considering routes to joint requirements analysis and joint specification development, as well as working together on a common evolution strategy.
The group agreed that common mobility management is an item for future consideration.
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