How much does it cost?
Cost is one of the questions still without a clear answer. Critics point to the many fees associated with Sprint's Airave femtocell service. First, there's the $100 cost of the box. Then there's the $5 monthly service charge, in addition to the fee for your regular calling plan and minutes used. If you don't already have an unlimited plan, you can opt to pay an extra $10 a month for unlimited Airave minutes; for families, that's an extra $20 per month. Finally, add the cost of your broadband service.
"If the 'network is everywhere,' it might be a hard sell to tell their customers, 'It's everywhere but in your house, and for that, we want another $100,'" said Allen Nogee, an analyst at In-Stat.
"You really can't sell these as stand-alone boxes," ABI's Carlaw says. Carriers will need to market the service as part of a flat-rate data plan, he says.
What if I switch carriers?
Because femtocells are locked to individual carriers, if you switch wireless providers, you'll need to purchase a new box.
Can I use my existing phone?
Yes. One selling point for femtocells is that they will work with your current cell phone. Similar services that use Wi-Fi for offloading home calls, such as T-Mobile's HotSpot@Home, require consumers to purchase a dual-mode handset.
Are femtocells just for voice calls or can I also use them for data?
Sprint's Airave, the only femtocell service commercially available in the U.S. today, supports 1xRTT data but does not support high-speed 1xEV-DO data. However, 3G femtocell services will provide high-speed data access in Japan in early 2009 and are likely to appear in Europe soon after, analysts say.
Can I take one on the road with me?
That depends on where you're going. While they're intended for home use, femtocells can be taken on the road (Sprint's Airave box is about the same size as a standard home router) -- provided you're staying in the U.S. and the wireless carrier offers coverage at the new location.
"The Sprint one uses GPS and won't transmit unless its location is within Sprint's territory and Sprint says 'yes,'" Nogee says -- an assertion confirmed by Sprint's Airave documentation (PDF). Sprint recommends that you check the ZIP code of the area to which you're traveling to confirm that the service is available there.
What's required for setup?
Femtocell devices require you to have a wired broadband Internet connection, such as DSL or cable; they won't work with satellite or dial-up connections. In addition, you must have an available power outlet and a free Ethernet port on your modem or router. And, of course, you'll need a cell phone and calling plan with the carrier offering the femtocell service.
Sprint's Airave box requires little setup or configuration; however, it must be located near a window for the GPS feature to work, according to Sprint's Airave documentation (PDF). The global positioning service "can take up to an hour to locate a satellite," according to Ovum analyst Steven Hartley.
Once set up, how well do they work?
Femtocells repeatedly scan the environment, seeking out the strongest signal to optimize the connection. Independent tests of Sprint's Airave from the likes of Engadget and Slashgear found the signal to be strong and clear in areas that were weak or nonfunctional without Airave. BusinessWeek, on the other hand, found the coverage to be spotty.
Once a connection is established, it won't exceed the maximum data rate of your broadband network, experts say -- something to keep in mind if you plan to have multiple callers using the service simultaneously.