Creating the enterprise femto network

WiFi and femtocell fixed-mobile convergence (FMC) have so far been targeted at the consumer, providing a blanket of dedicated coverage for a home or a small office. But now there’s a new target in site, the enterprise, which can’t be served by a single access point or femtocell. Nor can it be served by groups of access points or femtos, each in isolation. As a result, equipment makers and carriers are starting to tackle the problem of large-scale FMC networks, which could eventually transfer the benefits of the home hotspot to whole corporate campuses.

Last month Meru Networks and T-Mobile teamed up to extend T-Mobile’s Hotspot@Home platform to the enterprise. Hotspot taps into increasing number of WiFi-enabled phones T-Mobile offers, offloading traffic onto a customer’s home wireless LAN as well as T-Mobile’s network of hotspots. Traffic is taken off of T-Mobile’s macro network, and in exchange, customers get unlimited calls for a small monthly fee when connected via WiFi.

T-Mobile wants to take that model to large businesses, but going into the enterprise isn’t just a matter of installing @home software into a campus’s access points. The access points in the enterprise have to act as a self-contained network, not as individual hotspots. That’s where Meru comes in, integrating unlicensed mobile access (UMA) technology into its overall WLAN management platform. According to Meru, the single RF channel of the enterprise network creates a hotspot zone of sorts, allowing a user to traverse the length and breadth of the enterprise without losing a call or having to switch over to the cellular network. The cellular network itself views the entire WLAN network as one big hotspot, handing off calls and accepting handoffs to the network as a whole.

FROM WiFi TO FEMTO

Femtocell technology vendors are starting to apply those same concepts to the femtocell, which, unlike the WLAN access point, has never functioned as part of collective network before. Instead of following the WLAN model, though, femtocells are taking their cues from their big brothers, macrocells. While the femtocell has always been network-aware, its awareness extends only to the macrocells in its vicinity—the femto’s job being to take over connections from the macro network for only an authorized few, said Steve Shaw, vice president of marketing for Kineto, one of the key developers of UMA technology. Because of that personal relationship between a femto and its “family” of users, it has no need to communicate with other femtocells in the vicinity, each of which has its own family of authorized devices. Obviously that model goes out the window in an enterprise network, which could have hundreds of neighboring femtocells and thousands of authorized users, Shaw said.

“The femtocell has always been looked at as a single entity,” Shaw said. “What the operator wants to do now is come in and say, ‘I want to give you coverage across the entire enterprise.’ To do that, though, the operator has to think of the femtocells not as individuals but part of a group. Otherwise, you wind up going back and forth between the macro and femto network constantly when what you really want to do is move between the different femtocells in a group.”