by Caroline Gabriel
Airvana has been an early mover in CDMA femtocells, and is now making a new case for adopting the tiny base stations. It claims the root of many of the problems that users of smartphones like the iPhone experience are down to the way that these devices communicate with the macro network – problems that are not the same for USB dongles or notebooks, or for phones talking to femtocells.
The company says its researchers have identified some significant network usage characteristics that throw light on the challenge that complex smartphones offer to mobile operators. iPhone-type gadgets – in contrast to laptops or standard phones – create a ‘load multiplier effect’ that generates eight times the network signalling load of a dongle when transmitting the same volume of data, says Airvana.
This means that operators need to find ways to improve mobile data processing and to offload traffic from the macro network – some do this to Wi-Fi, but most operators are looking to femtocells, backhauled by consumers’ broadband lines, to share the data burden while remaining under the carrier’s control. This will become urgent, with shipments of smartphones expected to more than double in the coming few years (from 200m to 450m by 2013, according to one estimate from iSuppli), and with their users consuming more data on average.
Because smartphones, in typical usage, are constantly moving between cell sites and polling the network, they are already responsible for 2-3 times more signalling activity than laptops, especially in areas of dense networks and high usage (such as London, as lamented this week by O2 CEO Matthew Key, as he prepares to broaden the operator’s smartphone range).
“We really wanted to find out what was happening with this and get ahead of the problem,” said Airvana’s VP of marketing and product management, David Nowicki. He is not even referring to end-to-end signalling for applications like web email, which requires constant connection to the internet. This is about lower level signalling for
initiating layer 2/3 connections to supports apps or move between cells. “The smartphone has to do a lot of signalling just to send those small amounts of data,” said Nowicki.
As well as offloading traffic where possible, operators need to put in more optimized controllers for layers two and three, he added.