Femtocells: Pros and Cons

Are you one of those unlucky souls who enjoys decent cell phone reception when you're out and about but can't get a signal inside? You're not alone. Indoor signals have long been a weak point of cellular coverage.

That's why femtocell technology has created such a stir over the past year or so -- it offers the possibility of using a device like a broadband router to boost cellular reception indoors.

Analysts and the media speculated that consumers would see a flood of such devices, known as femtocells, by the end of 2008. Now, however, that timeline has shifted to late 2009 or 2010, as questions surrounding femtocells remain unanswered. In fact, only Sprint Nextel Corp. is currently offering a commercial femtocell product in the U.S.

That delay gives us time to learn more about the technology, including its benefits and drawbacks. Here's a primer.

What are femtocells? The term femtocell refers to the smallest unit of a cellular network and, by extension, the devices and services that make use of them. Other small -- but not quite as small -- cells include Wi-Fi cells (a.k.a. microcells) and Bluetooth cells (picocells). At the other end of the spectrum are macrocells, such as those used in carriers' cell towers.

What do they do? Femtocells address the problem of poor cell-phone reception indoors by taking advantage of the proliferation of home- and small-office broadband connections. Like the wireless router that distributes a Digital Subscriber Line or cable broadband signal throughout your home, a femtocell device -- sometimes called a miniature cellular base station or a mini cell tower -- grabs your carrier's cellular signal and boosts it for indoor use, routing your calls through the broadband connection rather than directly through the larger cellular network.

What are the benefits? Subscribers get a stronger, clearer, more reliable signal inside -- which means more users may finally be able to ditch their land-line phone service for good. Carriers benefit by being able to offload traffic from their main networks, saving them the substantial cost of building more cell towers.

How far do they reach? Femtocells have a range of around 5,000 square feet and are intended for use inside a single home or small office. If you leave the building in the middle of a call, the call is handed off to your carrier's nearest cell tower.

Where can I get one? Because femtocell devices are tied to wireless carriers using licensed spectrum, you have to wait for your provider to offer femtocell service.

In September 2007, Sprint Nextel became the first U.S. carrier to introduce a femtocell service, called Airave. The service was initially available in Denver and Indianapolis and was rolled out nationwide in August 2008. A femtocell box plugs into your existing router or modem, sending incoming and outgoing cellular calls through your broadband connection. Up to three callers can use the service at the same time.

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.

Can femtocells be used for data? Airave supports 1xRTT data but does not support high-speed 1xEV-DO data. However, 3G femtocell services will provide high-speed data access in Japan early this year and are likely to appear in Europe soon after that, analysts say.

What about security? Femtocells use proprietary security, with a firewall that sits between caller and carrier.

Critics of Airave have pointed out that the device ships "unlocked" to all Sprint customers -- in other words, anyone with a Sprint phone in range of your femtocell can use your connection. However, the company points out that in most cases, other users would have to be inside your home to be in range of the femtocell. You can also choose to restrict access to the service to up to 50 select phone numbers.

Whether other carriers will make their femtocell devices accessible to other customers by default remains to be seen.

Sutherland is a freelance writer who has followed the rise and fall of countless technologies over the years.

This is a print version of an article that ran originally online. Check here for a comprehensive FAQ on femtocells.

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