Mobile operator O2 is to start trialling femtocell networking technology in the UK.

With the aim of launching a full roll-out next year, the company has teamed up with NEC and Ubiquisys for the trial which is the largest yet in the UK, The Guardian reports. Some 500 users across the UK are to start testing the service this summer and, if successful, O2 hopes to launch femtocells across the UK in 2009.

Femtocell technology offers 3G speeds to your mobile phone even when you're indoors. It works like this: a small 3G radio base station sits in your home and hooks up to an existing broadband connection to link calls and data services to and from a mobile phone. All you need to get femtocells working in your home is a broadband connection.

Indoor 3G coverage

The low-powered femtocell technology can improve 3G coverage to your mobile phone when you're inside a building. At home you're often out of 'earshot' of standard 3G base stations, so 3G reception can be poor.

"This technology has the potential to support increased growth in the usage and consumption of services and data and could play a crucial role in underpinning the explosive growth of mobile broadband usage," Vivek Dev, Telefonica O2 Europe's chief operating officer, told The Guardian.

For mobile operators, the advantage of femtocells is that they allow bundled fixed line and mobile phone call packages to be offered, as well as free mobile internet roaming when at home which is likely to be a crowd-pleaser among users. The technology would also enable mobile phone operators to start eating into the home broadband market, competing with the likes of Sky, BT, and Virgin.

Mobile internet

"Our Apple iPhone is already driving unheard-of levels of mobile internet usage, and the introduction of flat rate data tariffs is expected to increase this further. Both of these place huge capacity demands on our networks, and because so much of that usage is at home, femtocells coupled with home broadband could provide an alternative capacity resource."

For consumers, another advantage is that femtocells will work on any mobile phone, not just high-end models that support UMA and Wi-Fi.

According to The Guardian, interest in femtocells has so far been cool. Vodafone reportedly has around 11,000 UK femtocell users, while O2 has "a few tens of thousands".

In Japan, where femtocell technology is more commonplace, one mobile phone operator has been supplying some of its users with free base stations. Softbank users with poor mobile phone reception at home have been sent femtocell stations free of charge in a bid to boost their indoor mobile reception.