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.

With this smaller set of more similar standards to go for, diplomacy behind the scenes was enough to persuade the vendors to all agree, and make a standard that can be implemented on today's mobile networks, using today's broadband services.

The eventual Iuh standard includes elements of Kineto's UMA/GAN, and other contributions for Nokia Siemens, Huawei and Alcatel Lucent.

"We'd have loved this to be 100 per cent GAN but we aren't foolish enough to believe that would be the case," said Steve Shaw, director or marketing at Kineto. "It's got some of the principles of GAN in it."

More on the timetable

Saunders is pleased to see the femto standard scheduled for Release 8 of the 3GPP standards, which also includes the LTE standards. That's a good landmark to aim for.

Although the femto standard won't actually work with an LTE radio interface, it may be useful to LTE networks. LTE handsets will be able to fall back to 3G - and while indoors will work better with a big share of a nearby 3G femtocell's bandwidth, than fighting for some attention from a remote LTE base station.

The Femto Forum also hopes to inspire other standards, to make sure femtos can fit with billing systems, and be managed remotely by the same management and provisioning systems currently used by broadband providers. The Forum now has an architecture which can make sure these are done efficiently says Baines.

This will also allow femtos to adapt to new technologies such as LTE, he says: "We have a generic framework. Whether you are talking about LTE, 3G or WiMax, an awful lot of what is needed is consistent. This 3GPP announcement, for a W-CDMA femtocell, is the first of many of those instances."

Future standards may arrive just as quickly, he suggests.

Will it work, though?

Although Saunders and the others are optimistic, things could still go wrong. Firstly, although the timetable is good, it could slip simply through the complexity of creating a standard to such a tight deadline.

It's possible that some vendors might show reluctance to sign off on a standard if they see others getting an advantage, but this is much less likely now the operators have flexed their muscles.