There's little doubt in the collective mind of the mobile sector that small cells will play a crucial role in LTE networks, whether as a strategy to enhance capacity in high-density usage areas, offload mobile data traffic onto Wi-Fi, or both. The question is: when? And the answer seems to be: not just yet.
That's not to say no one is deploying them. A number of operators have already deployed small cells to varying degrees, even in cases where it's mostly Wi-Fi hotspots for offload purposes.
But analyst firm Ovum says we're still waiting for the "big boom" in small cell deployments - and we'll still be waiting for it by the end of this year. And while deployments will continue this year, growth will depend on whether small cells are deployed indoors or outdoors. Ovum says that small cell solutions for indoor spaces will be a hot item this year. The same cannot be said for outdoor small cells, according to Infonetics.
"Although Infonetics has never been bullish about the rate of adoption of outdoor small cells, from the relatively modest scale of deployments in 2013 we now expect critical mass in outdoor small cells to be achieved a little later than previously forecast, still some two years out from now," wrote Richard Webb, directing analyst for microwave and carrier Wi-Fi at Infonetics, in a research note.
What's the holdup? Put simply, deploying small cells is difficult, and solutions and their capabilities vary. During a small cell panel at the Mobile World Congress in February, Miguel Marin from Vodafone Group Technology described his experience with small cell deployments, and gave a laundry list of things he wants small cell vendors to deliver.
"Going forward, we want to drive the products and the ecosystem forward. We want more compact form factors for easier deployment," he said. "We don't want an add-on for carrier aggregation. We want better hardware efficiencies with next-generation chips. We want regulators to facilitate location and site acquisition. We also want SON - that's happening now to an extent, but there's still a lot to do. And we also want a greater portfolio of backhaul solutions for greater flexibility."
The backhaul portion is worth reiterating, because it consistently comes up as one of the top concerns of operators when looking at small cells. Obviously, small cells aren't much use without a backhaul link to connect them. But small cells present backhaul challenges that operators typically don't see in macro cell deployments in terms of logistics, TCO and the eclectic mix of backhaul technologies that will be required to make it all work.