Standards Folks Crave 'Common IMS'
And why weren't they doing that before?
Well, 3GPP kicked off the whole IMS standards process with the GSM (mobile) community in mind. So ETSI, one of 3GPP's "organizational partners," picked up the baton for the fixed-line operator community in its TISPAN (Telecoms & Internet converged Services & Protocols for Advanced Networks) group. TISPAN has used the resulting work as the basis for its next-generation network (NGN) standards specifications, as well as feeding it back into the 3GPP and into other standards bodies, especially the International Telecommunication Union (ITU) . (See ETSI Issues NGN.) [Ed. note: You still there? Hello?]
Anyway, one of the important things TISPAN has done is address many of the issues surrounding the role of legacy services in NGNs. (See Tispan: IMS Plus and The Role of IMS in PSTN-to-VOIP Migration.) Or, as ETSI puts it: "The convergence between public switched telephone networks and IP-based data networks forms a major part of the TISPAN work, along with the planning for the re-use in the fixed domain of the, originally mobile only, 'IP Multimedia Subsystem' (IMS) developed in 3GPP."
Now, though, 3GPP and TISPAN are pooling their efforts for a "Common IMS." This, says ETSI, will "prevent fragmentation of IMS standards" and "bring enormous economies of scale and reductions in capital and operational costs." So, even if no one else likes the idea, budget-holders everywhere should be happy. (See 3GPP, ETSI Plan Common IMS.)
3GPP has created a new Services group, called SA1, which will work on the Common IMS specifications to be included in 3GPP Release 8, which should be "functionally frozen" by the end of this year. "Functionally frozen" means that, while no further functions can be added to the standard's release, detailed protocol specifications may still be required, and OA&M (operations, administration, and management) and test specifications will still need to be developed.
The next thing 3GPP needs to do, says ETSI spokesman Kevin Flynn, is get other groups, like the 3rd Generation Partnership Project 2 (3GPP2) , which develops standards for the CDMA mobile community, to sign on to the idea of IMS unification.
Flynn is also keen to point out that this doesn't mean the end of TISPAN, as that group will continue to develop standards pertaining to other technologies, such as ENUM and IPTV.
— RLM, INE, LR