Femtocells: delivering in-building mobile reception

The next generation of mobile network could be built in a totally different way to today's 3G infrastructure. The Femto...

The next generation of mobile network could be built in a totally different way to today's 3G infrastructure.

The Femto Forum, the independent industry association that supports femtocell deployment worldwide, and the NGMN Alliance, the group focused on the evolution to the next generation of mobile networks, will co-operate on how femtocells can be built into the architecture of next-generation mobile broadband networks such as WiMAX and LTE.

Femtocells are low-cost mobile phone base stations designed to provide 2G and 3G mobile phone access within buildings,

The two bodies will work together to ensure that next generation mobile networks can incorporate femtocells from the very beginning of their deployment rather than integrating the technology afterwards.

By using femtocells mobile operators can lower the cost of building the next generation of mobile networks. While the 3G mobile network has been built by building radio masts to span the country, Simon Saunders, chairman of the Femto Forum says the next generation of network like Mobile WiMAX or Long Term Evolution, the extension to 2.5G, will begin within buildings. "Femtocells could create an in-building next generation network first." This would enable users to benefit from the fast speeds more quickly and allow the operator to rollout the network over a long period to broaden coverage,

Saunders says there is a technical benefit too of using a femtocell as part of the next generation network. A femtocell device can use Mimo (multiple in, multiple out), which takes advantage of the radio waves that bounce off walls and metallic objects to keep bandwidth high.

A femtocell device works like a mobile phone aerial, but connects to the operator's network over the internet via the user's broadband connection, instead of expensiveƒb E1 ethernet lines used to connect mobile phone masts to the cellular network. Companies such as Radioframe Networks, ip access and Airvana sell femtocell products, specifically to tackle the problem of poor mobile reception at home or in the phone itself.

Mark Keenan, general manager, EMEA, Radioframe Networks, says, "Mobile phone networks are not good enough for enterprise telecommunications. Users have to share bandwidth and the mobile network does not always penetrate into buildings." Keenan says this a particular problem in SME businesses where users often use the mobile phone as their main point of contact.

Femtocells can also be used to detect when someone enters or leaves their home or the office, says Steve Mallinson, chief executive officer at ip access. "This can be used to detect the presence of someone automatically." The presence information captured by the femtocell can then alert other people of someone's availability. "The network knows you are home," he says.

Data access is the other application area, but people may question why a femtocell is needed in an office or home, where internet access is easily provided by a Wi-Fi router or wireless access point. Mallinson says, "I have my contacts on the Blackberry and I frequently get calls at home," so in spite of Wi-Fi, users will still run services like Blackberry that use the mobile phone GPRS network.

But it is in the area of new applications and next generation networks where femtocells promise to make the biggest difference.

A femtocell infrastructure could reduce capacity problems that occurred in earlier mobile network rollouts. "When GPRS was first rolled out, while London offered good coverage, the network could not support the population," says Rob Bamforth, principal analyst at Quocirca. For network operators, there is very little they can do to increase the capacity of the network. But Bamforth says femtocells are able to supplement existing cellular networks, by enabling the devices of mobile users to connect via a short radio link to a physical network.

Since the femtocell connects to the operator's network via the user's broadband connection, it has little impact on the capacity of the cellular network. With prices of femtocells falling to around £200 to £300 for a single device, Bamforth predicts the market is almost ready for mass consumerisation. "Once it hits the £100 mark, the cost will be roughly the same as a wireless router. This is the sweet spot." Bamforth belies that when this price is reached people will start buying femtocell devices for their homes and offices instead of wireless routers.

It is likely that many such devices will integrate a femtocell with a wireless router, allowing the user to connect to the internet via Wi-Fi and make mobile phone calls using the femtocell. The cost of the calls should be significantly cheaper, as the mobile phone is only connecting to a femtocell and not using the operator's cellular network.

Its success will depend on how femtocells are priced. Companies like Orange Business Services could offer femtocells as part of a voice and broadband service. If Bamforth's predictions are accurate then over the next 12 months operators could create different business models to allow users to mix and match between femtocells and broadband.

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