Femtocells & UC

Future mobile unified communications suites will doubtless rely to at least some degree on existing wireless technologies and services. But perhaps the most irritating aspect of mobile phones - 3G or not - is that cellular service often fades out indoors and in underground train stations and parking garages. (The analyst firm Quocirca reports that about a third of all small and medium-sized businesses have coverage problems.) Now, however, small book-sized devices nicknamed femtocells - also known as Access Point Base Stations, or APBSs (but who needs another acronym?) - can furnish crystal-clear indoor coverage, much to the delight of cellular phone users. Moreover, femtocells or "femtos" as they're called (a nickname of a nickname) can seamlessly handover a call-in-progress from the femtocell to the outside cellular base station, just like dual-mode cellular/WiFi phones. Thus, femtocells will give competing technologies a run for the money, increasing the number of alternatives available in the world of FMC (Fixed Mobile Convergence) and encouraging fixed mobile substitution.

There are still some possible flies in the ointment, as it were: There's still some question about interference forming between femtocells and base stations and femtocells that are too close to each other. Broadband Internet access is also necessary, which might affect PC users accessing the Internet via the same router as the femtocell. There are also some possible security issues under discussion.

Even so, femtocells, once they are put into mass production and their price comes down, should make a huge impact in both consumer and business communications markets, at least at the low end. Amusingly, homes, apartment buildings and small offices currently experiencing acceptable cellular service will probably be tempted to install femtocells anyway, partly to wring that extra bit of quality out of the system and partly to enjoy a portfolio of FMC-based features and value-added services, including VoIP, mobile video/TV and the transfer of large files.

Since communities fearful of microwaves don't like having big cell towers near homes or schools, femtocells enable the carriers to increase coverage - and 'sticky' coverage at that - without fear of lawsuits or expensive investments in infrastructure (when indoors, the femtocell backhaul traffic is directed over the Internet, not the carrier's network). Indeed, femtocells can speed the arrival of 3G and totally new wireless 4G broadband transport schemes, such as WiMAX and LTE (Long-Term Evolution). That's why the Femto Forum and the Next Generation Mobile Networks (NGMN) Alliance announced they would team up to ensure that DSL-piggybacking technology functions in mobile next-gen network environments immediately, rather than having to be tacked on years later. (As it happens, LTE is designed to be "femto friendly" with features such as cell registration and closed user groups.) The French electronics firm Thomson is even embedding an Airvana femtocell into a DSL modem, and RadioFrame Networks (RFN), which offers low-cost wireless base stations, now offers the second generation of its OmniRadio processor, which can ultimately be used to deliver low cost femtocell products for WiMAX and LTE networks.

Also, Motorola, an active member in the Femto Forum since 2007, now offers CDMA femtocell equipment such as the Motorola Femtocell Access Point 8000 Series, a small, low-cost, low-power, easy-to-install 3G access point, and the Femtocell 8100 Ethernet Gateway 8100 Series, another plugand- play device which extends 3G coverage indoors, and plugs into any broadband connection (cable or DSL) and has an integrated advanced router and firewall with 802.11b/g wireless access point capability, along with Quality-of-Service (QoS) for voice-over-data prioritization so your phone conversation will sound okay while using the Internet.

Original femtocell vendor start-ups such as Ubiquisys, RadioFrame, ip.access and Airvana have been doing deals with (or have been acquired by) larger companies. Cisco made a sizable investment in the UK-based femtocell company, ip.access, creators of Oyster 3G femtocell technology. (ABI Research has ranked ip.access as Number One in terms of implementation and innovation.)

Vodafone, one of the world's largest mobile carriers, has been dabbling in femtocell trials and has even suggested the idea of a "metrozone" wherein femtocells would be deployed in a way vaguely similar to a municipal WiFi mesh, with femtocell stations on lampposts or other convenient objects eliminating the need for carriers to build those big base station towers that communities love to ban from their territory. (One problem to be solved concerning this idea: How do you handle backhaul traffic from all of the little femtocells?)

In the U.S., the femtocell pioneer is Sprint Nextel, which is slowly deploying their Airave service, starting in Indianapolis and Denver. Sprint's Airave CDMA femtocell device (in reality a Samsung Ubicell) handles up to three simultaneous calls from ordinary existing Sprint mobile handsets over a coverage area of about 5,000 square feet. Sprint is looking into providing a business solution that can handle at least a dozen calls at the same time. One annoying aspect is that Airave demands that you use either its internal GPS module or your own device (via a GPS port) to confirm (establish a "GPS lock") that you're running the device in the USA (and to know your exact location in case you place a 911 call) - it's said to take about an hour to get a GPS lock during the initial setup. The Airave device costs $99.99, and the last time Yours Truly checked, the service costs an additional $4.99 a month.

UMA and Femtocells

One of the most successful "femtocell" deployments isn't really a femotocell at all: It's T-Mobile's HotSpot@Home service, available nationwide in the U.S. You get a Linksys or D-Link WiFi router that comes with the service that's optimized for Hotspot @ Home's UMA (Unlicensed Mobile Access) technology. You must use special dual-mode WiFi-enabled mobile handsets such as a Nokia 6086 or Samsung T409, to send voice calls via Voice-over-WiFi to the designated HotSpot when your handset is in the WiFi coverage area. (In addition to the Linksys and D-Link home routers, the service also works with the many T-Mobile HotSpots in Starbucks cafes and airports.) When you walk from the indoor WiFi coverage area to the outdoor TMobile cellular coverage area (or vice versa) the call will be handed off between GSM and WiFi environments as needed. The HotSpot @Home costs $9.99 per month in addition to your existing T-Mobile plan; for $19.99 a month you get the family plan, that handles up to five phones. Offsetting that is the fact that the service provides unlimited calling when in WiFi mode.

Although T-Mobile's HotSpot@Home service looks and behaves a bit like a femtocell, and many people (even Yours Truly) tend to mention it in passing when talking about femtocells, most experts wouldn't really classify it as a conventional femtocell - instead of your existing handset, you must use a dual-mode WiFienabled device for voice. That's because the service is based on UMA, a technology originated and championed by Kineto Wireless. However, Kineto Wireless is the first to assure everyone that UMA can in fact work in a femtocell environment, since although UMA was originally posed as a way to route GSM/UMTS voice calls over WiFi and dual-mode phones, it actually supports 3GPP connectivity from a dual-mode phone or laptop softphone over WiFi or femtocells that connect to an IP network. Being a basic transport "tunnel" to the core network, UMA can run over WiMAX, LTE, HSPA or whatever new technology will come along.

However you classify it, UMA continues to pop up in places all over the world, and continues to be a viable alternative to the IMS (IP Multimedia Subsystem) common service architecture slowly being built into the world's wireless and wireline infrastructure.

AT&T has tested femtocells among its own employees for about a year and now Ars Technica reports that AT&T is sending a survey to some of its customers, asking if they'd like to help them test some prospective femtocells: "AT&T's new product is a small, security-enabled cellular base station that easily connects to your residence DSL or Cable Internet, providing a reliable wireless signal on behalf of any 3G phone in every room of your house. The device allows you to have unlimited, nationwide Anytime Minutes on behalf of incoming or outgoing calls."

Current rumors are that AT&T may launch a femtocell service in 3Q or 4Q of 2009.

A Femtocell in Your Future?

Femtocells also allow you to access the Internet and transfer data, which will come as a relief to workers everywhere, since ABI Research reports that about 70 percent of mobile access to data is done from within buildings. ABI, incidentally, has predicted a rosy future for femtocells, projecting 70 million of them in use worldwide by 2012, serving about 200 million users.

All the industry needs is a new nickname for these little devices - "femtos" sounds too much like "mentos", those mint and fruit candies that have been sold around the world since the 1950s by the Perfetti Van Melle Corporation.

Richard Grigonis is Executive Editor of TMC's IP Communications Group.