16.1 3GPP


The European Telecommunication Standards Institute (ETSI) pioneered the concept of "Partnership Project" in telecommunications by establishing Third-Generation Partnership Project (3GPP) in December 1998. 3GPP was initiated as a global initiative for a single globally common 3G standard. However, different cellular operators in the three largest telecommunication market sectors ”America/South Korea, Japan, and Europe ”went in their own ways in determining the choice of technology. 3GPP was able to attract a large portion of the cellular market by providing both TDMA- and CDMA-based solutions. It is expected that almost all of the existing GSM-based networks will evolve into 3GPP-based solutions. Some of the IS-136 operators (e.g., ATT Wireless Systems) have also adopted 3GPP-based solutions. The scope of 3GPP is to produce globally applicable technical specifications and reports for 3G systems based on evolved GSM core networks (CNs) and the radio access technologies (RATs) supported by the CN. For the evolved CN, 3GPP has produced specifications for the general packet radio service (GPRS) system. For the RAT, it has produced specifications for enhanced data rates for GSM evolution (EDGE) and wideband CDMA (WCDMA) technologies.

3GPP is a collaboration agreement that brings together a number of telecommunications standards bodies, which are called organizational partners (OPs), for developing specifications for wireless packet networks. The current OPs are the Association of Radio Industries and Businesses-Japan (ARIB), China Wireless Telecommunication Standards Group (CWTS), ETSI, T1, Telecommunications Technology Association-Korea (TTA), and Telecommunications Technology Committee-Japan (TTC). 3GPP has also included industry fora and consortiums as market representation partners (MRPs). Some of the MRPs are 3G.IP, Global Mobile Suppliers Association (GSA), GSM Association, IPv6 Forum, UMTS Forum, Universal Wireless Communication Consortium (UWCC), and WMF. They provide guidance to the process so the standards meet the market requirements for services, features, and functionality.

The functional organization of 3GPP (Figure 16-1) consists of a project coordination group (PCG) that administers the work of technical specifications groups (TSGs). PCG is composed of OPs and MRPs. There are five TSGs, each with an area of responsibility. The TSG core network (TSG CN) is responsible for the specifications of the CN part of the system. Some of the important areas covered by TSG CN are user equipment, CN Layer 3 radio protocols (call control, session management, mobility management), signaling between the CN nodes, interconnection with external networks, O&M (Operation & Management) requirements, and mapping of QoS. TSG GSM/EDGE radio access network (TSG GERAN) is responsible for the specification of the radio access part of GSM/EDGE. It covers radio interface protocol layers, OA&M specifications for the RAN nodes, internal (Abis, Ater) and external (A, Gb) interfaces, and conformance test specifications for GERAN base stations and terminals. TSG radio access network (TSG RAN) is responsible for definition of the functions, requirements, and interfaces of the UMTS Terrestrial Radio Access network (UTRAN). It covers radio interface protocol layers , OA&M requirements, access network interfaces (Iu, Iub, and Iur), and conformance test specifications for base stations . TSG service and system aspects (TSG SA) is responsible for the overall architecture and service capabilities of the system. This includes charging, security, and network management aspects of the system. TSG terminals (TSG T) is responsible for specifying terminal logical and physical interfaces, terminal capabilities, and terminal performance/testing.

Figure 16-1. Organizational chart for 3GPP.

graphics/16fig01.gif

Each TSG has divided its responsibilities in a set of working groups (WGs); detailed technical work takes place in the WGs. TSG-CN has the following WGs:

  • TSG CN WG1 defines the terminal to CN Layer 3 radio protocols (call control, session management, mobility management, etc.). For example, CN1 addresses SIP call control and SDP protocols for the IM subsystem.

  • TSG CN WG2 is responsible for the customized applications for mobile network enhanced logic feature (CAMEL); this feature provides the mechanisms to support the same services independent of the serving network.

  • TSG CN WG3 specifies the bearer capabilities and the interworking functions toward both the UMTS terminal and the terminal equipment in the external network. It is also responsible for end-to-end QoS.

  • TSG CN WG4 specifies supplementary services, basic call processing, mobility management within the CN, and bearer-independent architecture. CN4 also specifies the mobile-specific protocol specifications within the mobile CN.

  • TSG CN WG5 is responsible for the interfaces specific to the UMTS Open Service Access (OSA) and is used to facilitate service implementations . CN5 develops application programming interfaces (APIs) for the OSA.

TSG-GERAN has the following WGs:

  • TSG GERAN WG1 is responsible for the radio frequency aspects of GERAN, radio layer 1 specifications, internal GERAN interface specifications, and the specification of GERAN radio performance and radio frequency system.

  • TSG GERAN WG2 is responsible for protocol above the physical layer and the interfaces between them.

  • TSG GERAN WG3 develops the conformance test specification for GERAN base stations and works on the O&M requirements and specifications for all GERAN nodes.

  • TSG GERAN WG4 works on the conformance test specifications for testing of radio aspects of GERAN terminals.

  • TSG GERAN WG5 works on the conformance test specifications for testing of all the protocols and services above Layer 2 for the GERAN terminals.

TSG-RAN has the following WGs:

  • TSG RAN WG1 works on the physical layer of the radio interface for UE and UTRAN.

  • TSG RAN WG2 is responsible for the radio interface architecture and protocols above the physical layer. It also works on the radio resource control and management procedures.

  • TSG RAN WG3 is responsible for the overall UTRAN architecture and the internal and access interfaces.

  • TSG RAN WG4 works on the RF aspects of UTRAN. For example, it looks into the minimum requirements for transmission and reception parameters.

TSG-SA has the following WGs:

  • TSG SA WG1 works on the services and features for 3G. The group sets requirements for the overall system and provides this in a high-level description, which is expanded by the other groups.

  • TSG SA WG2 is in charge of developing the architecture of the 3GPP network, based on the requirements by SA1. SA2 identifies the main functions and entities of the network and also the interfaces of the entities.

  • TSG SA WG3 is responsible for the security of the 3GPP system. SA3 is responsible for the security implications of new services.

  • TSG SA WG4 deals with the specifications for speech, audio, video, and multimedia codecs. It also deals with quality evaluation, end-to-end performance, and interoperability aspects for the codecs.

  • TSG SA WG5 specifies the management framework and requirements for management of the 3G systems.

TSG-T has the following WGs:

  • TSG T WG1 works on the conformance test specifications for the radio interface. T WG1 is organized in two subgroups: RF subgroup and signaling subgroup .

  • TSG T WG2 is responsible for the services and capabilities to be delivered on 3GPP terminals and ensuring that terminals meet the 3GPP objectives. In general, the group is responsible for terminal-based applications, features, and interfaces.

  • TSG T WG3 is responsible for the subscriber identity module (SIM), which is used by 2G systems, and the USIM (universal SIM), which is used by 3GPP systems. It is not responsible for the security algorithms (developed by SA3).

3GPP has already accomplished a lot in its endeavor to provide IP on cellular networks. It is consistently working toward evolving its network and radio technology to an all-IP paradigm. There are still open issues and unfinished tasks , which are scheduled and being sought in the next releases. 3GPP is working with IETF to utilize IP expertise in solving issues for its all-IP network. In addition, radio is being evolved to support faster data services. The partnership project is already using synergy from its OPs. 3GPP is looking into bringing IP transport inside the RAN. This, among other benefits, would help in reducing the cost of infrastructure by using the economy of IP technology. Faster downlink data transfer is also under development, and high-speed downlink packet access (HSDPA) is being specified for this purpose. If in the future a widely used application demands a faster uplink data transfer, then 3GPP needs to add that work item to its task list. 3GPP has selected SIP as session control protocol in the Internet multimedia subsystem (IMS). However, there are many tasks related to SIP that need completion. Some of these tasks stem from the specific requirements of cellular telephony (e.g., support of SIP-based supplementary services, support of SIP-based emergency calls). Some of the tasks stem from the narrow bandwidth of cellular (e.g., support of SIP compression). Further improvement in QoS is also desired, such as support for end-to-end QoS. There is also a task for WLAN and UMTS interworking; this would allow a cellular subscriber to access a high-bandwidth WLAN. Support of multimedia services (e.g., video conferencing, video streaming) is also in the list of work items.



IP in Wireless Networks
IP in Wireless Networks
ISBN: 0130666483
EAN: 2147483647
Year: 2003
Pages: 164

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