Femtocells, the indoor cellular base stations that are tipped to be a big seller in the next few years, could shake up the prospects of all wide-area network technologies, according to last month's Femtocells Europe 2008 conference in London. But before they appear on today's 3G networks, they have issues to overcome.

No trials yet

A femtocell, as Techworld readers know well by now, is a low-power indoor 3G base station, that uses the subscriber's own broadband to increase coverage in the home or office. It connects voice calls back to the mobile provider's network, and data services to that network or directly to the Internet.

There are still no public trials of femtocells and, despite high hopes a year ago, none were announced at the Femtocells Europe conference. Instead, French operator SFR announced delays to its femto plans. and others dealt at length with the difficulties.

Why bother with femtocells at all? They promise great benefits. Operators could give or sell 3G users a femtocell to provide faster data indoors, longer battery life (because close up to a base station, the handset will need use less power) and new services such as in-building media. At the same time, other users outside the house would benefit, because the femto offloads traffic, freeing up the macro net.

If the benefits are that obvious, why are we still seeing no visible activity? In 2007, ABI Research predicted 36 million femtocells would be shipped (and shared by up to 152 million users) by 2012. Analyst Stuart Carlaw is predicting a later growth, but still expects 45 million units shipped in 2013. "Femtocells will take a little bit longer to come to market, with 2010 being the year of plenty."

Standards delays

Part of the trouble is the standards. "T-Mobile has concerns about progress of femto standards," Zhongrong Liu, head of RN (radio network) technology strategy at T-Mobile told the conference. "Originally 3GPP standards weren't written with millions of tiny cells in mind."

Despite the Femto Forum's progress on standards, anyone doing things with femtos right now would have to take a non-standard approach. Those involved with femto standards make an analogy with the early days of DSL, fixed line operators bought into non-standard equipment and costs were high.

In Liu's view, the inclusion of femto standards in the 3GPP's release 8 specification due at the end of 2008, is only the start, and the fully complete optimised femto standard won't exist till the end of 2009. In particular, operators need remote management to avoid costly customer service issues.