Femtocell Is Edging Toward The Enterprise: Page 2 of 3

Who's Doing It
As more vendors offer femtocell devices, more operators are ramping up femto networks. Globally, more than 20 such trials are under way, according to Yankee Group.

Sprint was the first vendor to try femto in the United States, launching its Airave femtocell program, now a nationwide service, in September 2007. However, Airave is voice-oriented and doesn't support the high-speed EV-DO data service, considered a key enabler of enterprise femtocell networks.

AT&T is validating High Speed Packet Access (HSPA) femtocells, with broader scale deployment slated for the second quarter of 2009. AT&T is working with Cisco and Cisco's partner IP.access on a home integrated gateway. Meanwhile, Verizon has announced its CDMA femtocell product called Wireless Network Extender, and is also considering femtocells to accompany its LTE rollout. Comcast, as part of its investment in Clearwire, has indicated it will deploy WiMax femtocells, leveraging its cable network for backhaul.

The Verizon and Comcast developments highlight the use of femtocells with emerging wireless technologies where wide area deployment will be limited for some time. The theory is that users may tolerate wide area coverage limitations if they can get the service in key locations. Alcatel-Lucent, Cisco, Ericsson, Huawei, and Nokia Siemens Networks are some of the bigger vendors targeting this space, while the list of smaller specialists includes Airvana, AirWalk Communications, AirWave, IP.access, RadioFrame, and Ubiquisys. Expect major consumer networking gear players, such as Linksys (Cisco), Netgear, Sagem, Thomson, 2Wire, and Comtrend, to get in on the act.

Small offices and home offices will likely leverage consumer-oriented solutions, just as they do today with Wi-Fi access points. But now Alcatel-Lucent, AirWalk, Tango Networks, and Tatara Systems, among others, are targeting the enterprise space. Enterprise systems are more complicated because most businesses want systems that integrate with their existing PBXs and IP-PBXs -- which are anything but standardized in their interfaces.

Policy management in enterprise-oriented femtocell systems will allow organizations to enforce rules such as keeping on-campus calling local to the enterprise network and controlling which users have access to long-distance networks, conferencing, messaging, and short-code dialing. Enterprise systems will use Session Initiation Protocol (SIP) for control.

Enterprise femtocells will support a larger number of simultaneous callers (e.g., 16 instead of four) and smooth handover between femtocells. They will enable a single number for both desk phones and mobile phones, along with PBX features such as abbreviated dialing from the mobile phone and a single voice mailbox. However, such tight integration will require specialized gateways between the enterprise PBX that communicate with matching gateways in the operator network.

You can also expect femtocells to incorporate Wi-Fi capability, providing a universal wireless gateway for homes. This will help address the issue of how and when to give voice traffic priority over data traffic on a user's Internet connection.

Quality of service will be needed to provide voice priority, and this will be problematic if there's a separate Wi-Fi access point soaking up capacity on the ISP connection. Trials have shown this to already be a concern. The quality of the broadband Internet connection will be paramount, because good voice quality will require low latency and few dropped packets, neither of which is guaranteed by ISPs today. Providing accurate location information for 911 calls is also tricky.