Even as it makes an all-out effort to standardize the interface between a femtocell access point and a femto gateway, the Femto Forum is looking ahead to assure that international standards bodies consider femtos when developing specifications for LTE and WiMAX.
The organization’s vendor members, at the urging of the 40 percent — and growing — group of operators that comprise the Femto Forum, want to sort out the interface between the broadband network and the cell gateway, “making sure that when you plug your femtocell into your broadband … the femtocell has a point on the network to talk to that will speak its language and will accept traffic and send traffic to it in a completely consistent manner,” said Simon Saunders, chairman of the Femto Forum.
This is important because operators — among whom are new Femto Forum members AT&T, China Telecom, SK Telecom, Sprint Nextel and T-Mobile (international and U.S.) — want to retail femtocells.
“The thing we’re working on here is enabling interoperability between femtocells at the interface between the femto and the first node of the operator’s network, the gateway that aggregates the femto traffic together,” he said.
This sort of open interface would let operators use multiple vendors’ femtos to interface with a single gateway and clear the path for consumers to buy and self-install a femtocell confident that it will speak to the mobile network.
Farther out, the Forum is partnering with standards bodies to make sure that femtos are part of whatever is developed for fourth generation wireless, be that LTE or WiMAX, Saunders said.
“There are some tweaks within LTE and indeed within WiMAX that will make them all the more friendly to femtocells,” he said. “In 3G we very specifically have a case where over-the- air nothing can be different for existing 3G mobile phones to support femtocells. We don’t want any special changes affecting the handsets. With LTE there’s still a certain amount of fluidity which means that we can not only make it work but we can have protocols within the handsets to do something things that are really optimized for femto activities.”
That’s the road map which, for now, is rolling through the femtocell to gateway interface standardization process pushed by operator members who “said ‘We’re glad you’ve come up with solutions; there are too many, sort it out, sort it out quickly,’” Saunders said. “Vendors have responded to this and now they’re aligned … (and) committed to following an open standards path.”