The GPRS recommendations belong to the GSM recommendations. The maintenance of all GSM recommendations is now handled within the Third Generation Partnership Project (3GPP) organization, the partners of which are:
- ETSI, the European standardization entity;
- Association of Radio Industries and Businesses (ARIB) and Telecommunication Technology Committee (TTC), the Japanese standardization entities;
- Telecommunication Technology Association (TTA), the Korean standardization entity;
- T1, the American standardization entity;
- China Wireless Telecommunication Standard (CWTS) group, the Chinese standardization entity.
These standardization bodies have decided to collaborate within the 3GPP organization in order to produce specifications for a third-generation mobile system. At the beginning, the 3GPP organization was in charge of all specifications related to the third-generation mobile system for radio access technologies called Universal Terrestrial Radio Access (UTRA) and for evolution of GSM core networks.
Since August 2000, specifications related to GSM radio access are also the responsibility of the 3GPP. The 3GPP takes the place of the former Special Mobile Group (SMG) GSM organization. The 3GPP is organized around technical specification groups (TSGs) that deal with the following subjects:
- TSG SA (Service Architecture), dealing with service, architecture, security, and speech coding aspects;
- TSG RAN (Radio Access Network), focusing on UTRA radio access technologies;
- TSG CN (Core Network), dealing with core network specifications;
- TSG T (Terminal), covering applications, tests for 3G mobiles, and the USIM card;
- TSG GERAN (GSM EDGE Radio Access Network), focusing on GSM radio interface, A and Gb interfaces.
Thus GSM evolutions as GPRS are treated in all TSGs except TSG RAN, which deals exclusively with UTRAN access technologies such as frequency division duplex (FDD), time-division duplex (TDD), and CDMA 2000. The TSG GERAN deals exclusively with the GSM radio interface evolutions and with A and Gb interfaces. The 3GPP recommendations are ranked according to a version reference.
Each new version of 3GPP recommendations contains a list of new features or a list of improvements on existing features. Initially, the GSM recommendations versions were referenced in the following order: Phase 1; Phase 2; Release 96; Release 97; Release 98; Release 99. As the reference year for the new version of phase 2++ recommendations no longer matched the release year of these specifications, it was decided that the versions following Release 99 will be referenced according to a version number, Release 4 being the first new version reference.
The GSM recommendations are organized up to Release 99 in the following series:
- 01 series: General;
- 02 series: Service Aspects;
- 03 series: Network Aspects;
- 04 series: MS-BS Interface and Protocols;
- 05 series: Physical Layer on the Radio Path;
- 06 series: Speech Coding Specification;
- 07 series: Terminal Adaptors for MSs;
- 08 series: BS-MSC Interface;
- 09 series: Network Interworking;
- 11 series: Equipment and Type Approval Specification;
- 12 series: Operation and Maintenance.
Each of the series contains a list of specifications identified by numbers. A given specification is therefore defined by its series number, followed by a recommendation number. For example, the 05.03 specification belongs to the physical layer on the radio path, and deals with channel coding issues.
In Release 4 of the 3GPP recommendations, the former GSM 01, 02, 03, 04, 05, and 06 series were kept for all GSM features that have not evolved with the third generation. From Release 4, these GSM series numbers were replaced by new series numbers, to be compliant with the 3GPP numbering. New series numbers can easily be deduced by adding 40 to the GSM series. Thus the 05 series describing the physical layer on the radio path become the 45 series from release 4. Also, the specification numbers in each series are deduced from the previous numbers by inserting a 0 as the first number. Thus, the R99 05.03 becomes the 45.003 from R4. Note that the different releases are continuously maintained.
The GPRS feature was introduced in Release 97 of the 3GPP recommendations. The GPRS recommendations are organized in three stages, as are all 3GPP recommendations:
- Stage 1: Description of GPRS services;
- Stage 2: Description of GPRS general architecture;
- Stage 3: Detailed description of different equipment implemented for GPRS with their external interfaces.
The Stage 1 GPRS recommendations describe the services that will be provided by GPRS. The service description is given in the 02 series recommendations for Release 97 and Release 98 of the 3GPP recommendations and in the 22 series recommendations from Release 99. The evolution of GPRS services is discussed in Working Group 1 (WG1) of TSG SA within the 3GPP.
The stage 2 GPRS recommendations describe the general architecture of GPRS, with nodes implemented in the network and the interface mechanisms between these nodes. The description of the architecture is given in the 03 series of the recommendations for Release 97 and Release 98 of the 3GPP recommendations and in 23 series recommendations from Release 99. The evolution of GPRS architecture is discussed in WG2 of TSG SA within the 3GPP.
The stage 3 GPRS recommendations describe in a detailed manner the equipment and its external interfaces implemented in the network for GPRS (see 04, 05, 06, and 08 series recommendations up to Release 99, and then 44, 45, and 46 series recommendations from Release 4). The evolution of the behavior of this equipment is discussed in working groups of several associated TSGs.