Aussie telcos mull mixed cellular-Wi-Fi networks

Network equipment makers are pushing technology that enables mobile data traffic to be "steered" in real-time between cellular and Wi-Fi networks, but Australia's telcos are unlikely to have a use for it in the short to mid term.

Are carriers steering towards mixed cellular-Wi-Fi networks?

Ericsson and Nokia-Siemens Networks used the CTIA 2013 wireless event in Las Vegas late last month to unveil separate but similarly-targeted technologies that build on the concept of heterogeneous networks ('HetNets').

A HetNet architecture sees traditional macro cells augmented with — or deconstructed into — a dense network of smaller cells, coupled with intelligent software to manage data traffic.

It is meant to relieve congestion issues in large cells and is seen as an alternative to current strategies such as cell splitting.

Independent telecommunications analyst Chris Coughlan told iTnews that carriers, such as Telstra, have been busy splitting congested macro cells into, for example, four or five smaller cells. However these smaller cells still operate with traditional base station equipment.

"Cell splitting from a CapEx perspective is really expensive," he said, noting a greenfields cell site could cost upwards of $250,000.

"HetNets basically take cell splitting to another level".

HetNet talk to date has been about the use of cheaper, shrunken base stations, such as lightRadio devices by Alcatel-Lucent and Liquid Radio boxes by Nokia-Siemens Networks. Such boxes require less power and bandwidth than a traditional macro base station, and can be stacked together or distributed across areas of high mobile data demand.

Equipment vendors are also pushing for carrier-grade Wi-Fi to be added to the HetNet mix.

In such a scenario, "real-time" or "dynamic" traffic-steering software in the network would direct users into LTE, 3G or Wi-Fi cells, depending on which offered the best, least-congested browsing experience.

However, with all three of Australia's mobile carriers holding considerable spectrum assets, the need to branch out into mixed Wi-Fi/cellular networks is likely to be some way off.

Early adopters

Australia's telcos are a mixed bag when it comes to HetNet adoption.

Telstra is known to be toying with HetNets, but as a point solution at stadiums and racecourses — basically areas that can become highly-congested at certain points in time. Last year, it trialled an unnamed small cell technology at Flemington Racecourse (pdf).

It appears the telco isn't necessarily thinking about HetNets yet as a ubiquitous mobile network architecture strategy. Comment is being sought from a Telstra spokesman.

Spokespeople for Optus and Vodafone Hutchison Australia (VHA) say that they are tracking the development of HetNets closely, but both are yet to really dip a toe in.

Equipment vendors vying for a piece of the HetNet action in Australia believe carrier interest in the concept is there, but that it will ultimately take time to achieve broad-scale adoption.

The vendors agree that small cell technologies will only proliferate when telcos have exhausted options to optimise existing macro cell sites.

"Once the macro network has been optimised, that's when small cells come into play and that's when Wi-Fi can play a role as well," Ericsson Australia's manager of strategic marketing, Andres Torres said.

Initially, it seems that small cells will use cellular radio technology (based on the 3GPP GSM standard) rather than carrier-grade Wi-Fi, though vendors believe Wi-Fi still has potential.

"It depends on each operator's strategy," Torres said.

Ericsson is coy when it comes to revealing the presence of any local trials of its technology. Nokia-Siemens Networks is less so, noting no current local trials of its competing Smart Wi-Fi steering solution.

NSN's Asia Pacific head of E2E solution architecture, Mike Smathers, believes the opportunity presented by a mixed cellular-Wi-Fi network is still being evaluated.

"I think no doors have been closed," he said.

"[Operators are] faced with looking at all kinds of ways of enhancing the 3GPP macro network that they've got at the moment, and the next step after that would be to deploy small cells.

"Those small cells could be in the form of microcells, picocells, femtocells and even Wi-Fi. I think that these are all options that [operators have] on the table, that they're kicking around."

Read on for views on whether Wi-Fi can cut it.