Small cells will inevitably be a major theme of this year's Mobile World Congress, as they were in 2012. However, the debate will have moved on significantly. In the past year, the idea of building dense, high-capacity networks from hundreds of tiny base stations has shifted from an interesting concept to being part of carriers' real-world plans.
Some, like Softbank in Japan and Vodafone in the Middle East, are already testing public access "metrocells" outdoors and indoors. But there are still challenges before the approach expands from a few pioneering experiments to a mainstream element of operators' network planning. One is how the thousands of cells - hundreds of thousands, within a few years, AT&T thinks - will be managed to deliver profits and quality of experience, not chaos and interference.
Talking to vendors and operators about their plans, it is clear this will be one of the most important topics at the show, and it has been given new impetus by Cisco's announcement that it is buying Intucell, a pioneer in the kind of self-optimizing network (SON) techniques that will help carriers make the most of their small cell metrozones. Intucell's flagship customer for its "dynamic SON" software is AT&T, which also works closely with Cisco on its small cell strategy.
The deal signals the next small cell gold rush. Even if the base stations themselves rapidly become commodities, there will be significant growth in tools to plan and manage them to deliver the greatest benefits. According to our research, 51% of mobile operators expect to invest in entirely new platforms for optimizing small cell networks driven by LTE, usually in the first year of commercial roll-out. These tools will, they believe, be necessary even though SON capabilities are increasingly included in the LTE standards, especially from Release 10, and supported by many equipment vendors.
In a survey of over 40 large mobile operators, Maravedis-Rethink, found a significant difference in attitudes to LTE network management and planning, between those majoring on small cells and those sticking mainly to conventional larger-cell approaches. Just over half of respondents believe they will need to invest in new platforms to manage and optimize networks of LTE or multimode small cells while fewer than one-quarter have the same urgency for LTE macro/micro cells.
SON (which can be defined either as self-organizing network or self-optimizing network) is essential to make small-cell networks workable. However, most operators believe that, although standards will support a fully automated network, they will not be enough to deliver one that is fully optimized to deliver maximum targeted capacity and all the potential benefits. Only one-fifth of carriers think SON standards alone will be enough to deliver the results they want from small cells, whereas almost 40% are content with standards in more conventional roll-outs.
To fill the gaps, suppliers are increasingly offering their own added-value SON features, though keeping - and enhancing - the standards as a base will be important to cost economics, and to issues of interoperability in multi-vendor small cell networks.