What is a femtocell?

Mini base stations are headed for every corner of the Earth but do you need a femtocell?

When it comes to telecommunications, Australia isn’t usually far behind the curve. In 2010, we had the third highest number of mobile broadband subscribers per capita, our average broadband speeds are growing by the day, and let’s not forget that the National Broadband Network will be one of the few nationwide fibre-to-the-home deployments so far.

By the end of 2011, we’ll have two of the few true LTE fourth-generation mobile networks in the world — trailing the US, northern Europe and Portugal — and Telstra continues to be widely regarded as a bastion of network engineering by its counterparts.

But on the topic of femtocells, local carriers have been somewhat quiet.

Most people might not have even heard of the term, at least before Optus announced the country’s first commercial trial of a home-based femtocell. The Optus 3G Home Zone isn't the first local femtocell offering; Vodafone also offers two different femtocells, which are aimed at serving between four and 16 users in businesses.

There has also been some interest among other local carriers; vividwireless' predecessor, Unwired Australia, became a member of representative organisation Femtoforum in 2007, but never announced any products or trials. A spokesperson for vividwireless confirmed the company had explored the technology but had no current plans to release it commercially.

Basic versions of a femtocell have been available internationally since at least 2006 as GSM voice boosters or 3G data access points. In 2010, the number of femtocells around the world exceeded the number of macrocells, according to the Femto Forum. The number of access points is forecast to grow to 49 million by 2014, according to research from Informa Telecoms & Media. Australia is yet to be included in those statistics.

That local carriers are unwilling to dive headfirst into the technology — or at least are doing so quietly — raises the question: Is it all worth it?

But what is a femtocell?

Femtocells are small, modem-like devices that, when connected to a fixed broadband connection, function as a miniature version of the base stations upon which mobiles, smartphones and, increasingly, mobile broadband–equipped laptops and tablets rely for Internet access.

The access point can route nearby wireless voice and 3G traffic through the broadband connection in a similar way that established ‘macro’ mobile towers use either fibre or microwave links as backhaul to a carrier’s infrastructure. By doing this, femtocells can provide coverage for smartphones and mobiles that can improve call quality and increase data download speeds.

Some enterprise femtocell offerings can do more than just extend coverage indoors. For instance, some femtocell products route traffic directly through an enterprise PBX so that users can receive calls to their four-digit office extension or to their mobile number on their mobile phones.

There are difficulties in deploying and subsequently using femtocells, however. According to Ericsson Australia’s head of strategic market, Kursten Leins, spectrum planning and sharing becomes an important factor, potentially preventing their use in dense, urban areas.

“As soon as you introduce a signal [to] noise ratio you start shrinking the cell size, which has the effect of reducing your throughput to customers, and it's a spiral,” he says. "You could have very clustered use of these services which then effectively means your benefit for in-building coverage is diminished; the end outcome may not be as nearly as good as you expect for customers.”

Leins says there is an additional technological difficulty in planning for femtocell use, which could possible cannibalise existing coverage.

"You have to literally start mapping where the femtocells are," he said, adding that as "you start going down to a more granular level, it adds cost to the equation."

Am I really paying double?

One of the major criticisms of femtocell networks is the notion that customers could in effect be paying twice for the privilege of using a better quality service. That’s because the add-on cost of a femtocell device, unsurprisingly, doesn’t subsidise the ongoing call and data charges from a carrier. For an Optus 3G Home Zone, then, you’re adding at least $5 a month for a year, or $60 upfront, to your bill for better coverage.

It has led some, like Telsyte analyst Foad Fadaghi, to slam the commercial model as unviable.

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Tags smartphonesmobile phonesTelecommunicationsfemtocells

More about Ericsson AustraliaEricsson AustraliaetworkInforma AustraliamobilesOptusTelstra CorporationTelsyteUnwired AustraliaVodafone

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