How important is the 3GPP femto standard?
It's driven by operators, so it might work
By Peter Judge, Techworld | Techworld | Published: 22:00, 09 June 2008
Last week's announcement of a standard for femto cells took a lot of people by surprise. How did it happen so fast, and how important will it be? And are there other issues that might cause problems in future?
Standards often take forever to develop. This time round, the Femto Forum appears to have created a compromise which the 3GPP standards group is happy with, very quickly indeed. From all accounts, it will be a
There are two main reasons for this.
Customers come first
Firstly, the actual customers have been involved much more heavily than in many other standards.
Many technology standards are made in groups like IEEE, where a series of vendors push a set of technology solutions, more or less in isolation from users. Eventually one wins, or compromises are made, but these are often based on abstract technological features, with a not-so-hidden commercial advantage for one supplier or another.
Simon Saunders, chair of the Femto Forum, puts it more diplomatically: "What you are usually doing is making it up by committee, creating a paper standard, which you then go off and implement." In this case, there were existing products, he says.
Femtos have the advantage that in the telecoms world, standards are made for a comparatively small set of customers (the mobile operators), all of whom could have a large stake in the success or failure of femtos.
The Femto Forum has raised their consciousness and, in this instance, apparently inspired them operators to make a collective ultimatum: one standard only please. "Raising expectations was the best way to move things forward quickly," says Femto Forum chair, Simon Saunders, and much of this was done by the chair of the Forum's working group, Chris Fenton. Once they saw the problem, the operators put forward absolute requirements.
Faced with a list of user requirements, the vendors did something rarely heard of in a standards meeting - they accepted that none of their solutions met all the requirements, and developed a common answer,
SIP/IMS can wait
A second factor helped bring about this consensus. Inspired by the operator ultimatum, vendors pushed back more long-term approaches based on two elements: IMS, the multimedia platform that telecoms networks are supposed to be adopting over the next few years, and on SIP, the protocol used in VoIP.
"The idea of IMS-connected femtos seems to have been kicked into the long grass for now as far as 3GPP and Release 8 is concerned," says Dean Bubley of Disruptive Analysis.
Shaw agrees: "IMS and SIP adds a lot of complexity, and operators are looking for a short term pragmatic approach. They don't want to have to jump into IMS just to do one thing." Operators still believe that SIP and IMS are the next step for mobile operators, but no-one expects them to be implemented fundamentally until LTE rolls out.
This meant a radical pruning of femto contenders: "Three months ago, there were something like 14 different proposals, including four or five really fundamentally different attitudes to the world," says Rupert Baines, vice president of marketing at picoChip, which designs silicon for femtos.
As well as SIP/IMS, the traditional IUb protocol was rejected as were new standard protocols.
The process left only four proposals, all of which were roughly similar, based on a RAN (radio access network) gateway. "None of them are SIP based, and all work with existing GSM protocols," says Steve Shaw, vice president of marketing at Kineto which backed the UMA process based on GAN.