It’s an experience that everyone’s probably had — inadequate wireless coverage at home or work. But this may change in the near future due to a big idea that’s gotten little attention so far: the femtocell.
The idea of a femtocell is actually remarkably simple: it’s a cell phone tower shrunk down to fit inside your home or office.
Such things aren’t entirely unprecedented. Cell companies have long been working with "microcells" and "picocells" to offer improved coverage in strategic areas like malls and convention centers. Traditionally though, if you wanted to improve your cellular signal in a building, you bought a cellular amplifier for around $200 to $300, mounted an antenna somewhere outside where it could get a clear line to a tower, then put another antenna indoors where it rebroadcast the signal. This worked, but it was awkward and expensive, and not a lot of people wanted to bother.
A femtocell is a much more straightforward device — rather than rebroadcasting, it puts all the hardware for communicating with your phone right in the device… and then it connects to the Internet.
And that’s it. No rebroadcasting necessary. How it does this is complicated, but the best way to think of it is as a hotspot, not for Wi-Fi, but for the cellular network. The femtocell provides a low-power version of exactly what a cell phone expects to see, but instead of redirecting the traffic to the rest of the network, it sends it out to the Internet. Data service goes direct, and calls get routed over VoIP. Unlike Unlicensed Mobile Access, this solution doesn’t require special phones, or even that you have Wi-Fi.
The possibilities are obvious, if the devices can be made cheaply enough: high quality cell phone coverage in every home and office, in a win for customers. Less drain on the cellular networks, as people use their mobile phones to replace landlines, which benefits the carriers. Ericsson is even touting a model that also includes the functions of a DSL modem and Wi-Fi access point, creating a single-box solution for all home connectivity.
Of course, it’s not all as easy as that. There are a number of technical and logistical hurdles that make femtocells a tricky proposition, and each carrier has to offer their own version, due to the restrictions on licensed frequencies. But the potential payoff is astronomical.
I must point out here that one of the GSM bands which is used overseas overlaps slightly with the unlicensed 900 MHz band in the United States — in theory, it might be possible to build a GSM femtocell that supports world phones without going through the difficulties of working with a carrier. However, that would require a daring engineering genius. Paging daring engineering genius, you’re needed in the lab.
Never mind even the problems of carrier specific hardware: the fact that a femtocell uses the Internet for "backhaul" means not just the fastest Internet speeds your hardware and connection support, but it can also enable cheap or even free unlimited talk minutes, including around the world, much like pure VoIP solutions like Skype.
Unfortunately, you’re going to have to wait a little while for this to hit the U.S. Even the most aggressive carrier, Sprint, is only running pilot projects with femtocells at the moment, and other carriers have yet to pick up the idea. All this means that it may be years before the devices are widely available here. But unless the cellular networks get replaced by WiMAX first, it’s likely that in the not too far future, you’ll be able to enjoy your own home-baked phone coverage.