The Femto Forum has set out plans to help develop standards for the emerging technology of indoor 3G base stations, and announced new members including BT and Cisco.

The Forum, formed in July 2007, intends to build compatibility into femto cells, which operators are considering offering to consumers. They provide a 3G signal indoors and use broadband to connect calls back to the cellular networks over the Internet.

The technology is predicted to be serving 100 million people by 2011 (according to ABI Research), but is still only being tested in secretive trials by operators. Without standards, operators will be less likely to commit to it, and users will not be able to choose equipment from different vendors.

Formal standards for femto cells will eventually be made in bodies such as 3GPP, but until now vendors and operators have been working in isolation on different technology approaches, said Simon Saunders, chair of the Forum. "The Forum has been cataloguing the different approaches, and it is clear from the operators' point of view that there are too many of them."

The lack of standards is not holding up commercial deployment of femto cells, he said: "This is not a requirement for launches, but it will become more and more important." The Forum won't settle disputes between different camps such as UMA and SIP, but it will help settle a framework and build consensus around a limited number of approaches, to make the standards bodies' work easier, said Saunders: "Everyone is agreed the fewer flavours the better."

"I've been really impressed with the amount of serious intent from all vendors to find a way to give the operators what they want," said Andy Tiller, vice president of marketing at ip.Access. "We recognise that if some of us succeed in locking operators in, it’s not going to be good for the industry."

"All the operators are racing to market very rapidly," said Paul Callahan, vice president of business development at femto maker and Forum member, Airvana. "Femto cells are a competitive weapon, and every operator has a different set of preferences." Although operators are going ahead, there are issues to sort out, he agreed: "The whole year will be spent getting it right."

Operators want to be sure that femtocells from different vendors can be plugged into their networks, and management systems can expand to handle potentially millions of the devices.

Unlike voice on Wi-Fi, femtocells can provide indoor voice and data to existing phones, not just dual-mode ones, said Saunders.

The Forum's new members, include operators such as BT, Vodafone and Telecom Italia, showing operators are indeed taking femtos seriously. Other new members include Cisco, which bought a stake in femto vendor ip.Access last week, as well as Ericsson, Huawei, Samsung, Softbank Mobile, Telecom Italia and Vodafone.

Why femto cell vendors mean business now? Read an in-depth analysis here.