Introducing 3GPP
3GPP specifications cover cellular telecommunications technologies, including radio access, core network and service capabilities, which provide a complete system description for mobile telecommunications. The 3GPP specifications also provide hooks for non-radio access to the core network, and for interworking with non-3GPP networks
The Project’s Scope
The original scope of 3GPP (1998) was to produce Technical Specifications and Technical Reports for a 3G Mobile System based on evolved GSM core networks and the radio access technologies that they support (i.e., Universal Terrestrial Radio Access (UTRA) both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes).
The scope was subsequently amended to include the maintenance and development of the Technical Specifications and Technical Reports for evolved 3GPP technologies, beyond 3G.
- The latest 3rd Generation Partnership Project Agreement (Annex 42).
- The discussions that led to the signing of the 3GPP Project Agreement were recorded in a series of slides called the “Partnership Project Description” that describes the basic principles and ideas on which the project is based. The document has not been maintained since its first creation, but the principles within do still remain valid.
Organizing the work
The 3GPP Working Procedures are the rule book of 3GPP, with sections covering:
- Description, Purpose, Scope and objectives
- Participation
- Structure
- Partners’ collective responsibilities
- Project Coordination Group (PCG)
- Technical Specification Groups (Incl. Elections)
- Work Programme & technical co-ordination
- Deliverables (Technical Specifications and Technical Reports)
- Reporting
The 3GPP production of specifications and studies (TRs) are contribution-driven, by member companies, in Working Groups and at the Technical Specification Group (TSG) level. The Technical Specification Groups in 3GPP are:
- Radio Access Networks (RAN)
- Services & Systems Aspects (SA)
- Core Network & Terminals (CT)
The Working Groups, within the TSGs, meet regularly and come together for their quarterly TSG Plenary meeting, where their work is presented for information, discussion and approval. The last meeting of the week of TSG Plenary meetings is TSG SA, which also has responsibility for the overall coordination of the technical work and for the monitoring of its progress.
Generational Approach
The 3GPP technologies from these groups are constantly evolving through Generations of commercial cellular / mobile systems. With LTE and 5G work, 3GPP has become the focal point for the vast majority of mobile systems beyond 3G.
Although these Generations have become an adequate descriptor for the type of network under discussion, real progress on 3GPP standards is measured by the milestones achieved in particular Releases. New features are ’functionality frozen’ and are ready for implementation when a Release is completed (see Release dates at https://portal.3gpp.org/ & select 'Releases'). 3GPP works on a number of Releases in parallel, starting future work well in advance of the completion of the current Release. Although this adds some complexity to the work of the groups, such a way of working ensures that progress is continuous & stable.
Backward Compatibility
The major focus for all 3GPP Releases is to make the system backwards and forwards compatible where possible, to ensure that the operation of user equipment is uninterrupted.
For 5G, many operators are starting with dual connectivity between LTE and 5G NR equipment – using the ‘Non-Standalone’ work completed early in Release 15. In the process of completing the early drop of 5G NR care has been taken to build ‘forward compatibility’ into Non-Standalone NR equipment, to ensure that it will be fit for use on Standalone 5G NR systems.
For details of the contents of each Release, see the appropriate ’Release Description’ document or go to our dedicated Release page.
Details of all 3GPP Work Items are in the 3GPP Work Plan, which provides details of the cooperation between all of the 3GPP groups on “Features”, defined as ‘new or substantially enhanced functionality which represents added value to the existing 3GPP system’.
Quick-start presentation
The Chairs of the three Technical Specification Groups and the 3GPP Work Plan coordinator have prepared a slideset aimed at newcomers to the project and those in need of a refresher course on a variety of topics.
The presentation looks at the key areas of: What the 3rd Generation Partnership Project is; What the 3GPP 'Outputs' are; Details on the structure of the groups and How to contribute to the work.