April 30, 2013, 5:59 PM — Consumers will have to share small, inexpensive cells in their homes with nearby mobile users to affordably meet the growing demand for mobile data in the next decade, a Qualcomm executive said Tuesday.
"There really is no alternative," said Matt Grob, Qualcomm's executive vice president and chief technology officer, during a presentation at the Qualcomm On conference in Santa Clara, California.
A reference design for such a cell, which Grob showed during the speech, would fit in the palm of one's hand. It could cost less than a cellphone and might be integrated into set-top boxes, game consoles, home broadband gateways and other devices, Grob said.
Shared in-home small cells are only one part of Qualcomm's vision for increasing the capacity of mobile networks. Within about 10 years, networks will need about 1,000 times as much capacity as today's traditional macro cells alone provide, according to Qualcomm. Like mobile operators and the rest of the industry, the company also believes more radio spectrum needs to become available for mobile. For example, Qualcomm advocates mobile users sharing the 3.5GHz band, which might be used for its in-home small cells.
But adding more spectrum will only increase capacity by about 10 times, Grob said. The remainder of the boost will have to come from other steps, namely deploying more, smaller cells to reuse the same frequencies more efficiently. Carriers also are planning smaller cells, with AT&T making one of the biggest commitments to that approach in the U.S.
But Qualcomm's concept, which it has discussed with AT&T, goes beyond the common industry vision of carrier-deployed small cells in buildings and dense public areas. Among other things, in-home small cells could reduce the cost and complexity of deploying public small cells and linking them to wired networks, Grob said.
Many consumers already use so-called femtocells, which are essentially small, in-home cellular base stations supplied by mobile operators solely for a family's use within their own walls. One challenge femtocells raise is interference with macro cells and other femtocells if they project their signals outside the home.
Qualcomm essentially wants to turn a femtocell's outdoor signals from a liability into an asset.
"An interesting thing happens," Grob said. "A little bit of that signal leaks outside and starts to provide little pieces of coverage outdoors. And if enough of it is happening indoors, then pretty soon you end up with pretty good outdoor coverage."
At the heart of its vision is UltraSON, an implementation of SON (self-optimizing network) technology that Qualcomm would use to turn many cells spread across a neighborhood into a unified network. Coordinated operation can not only prevent interference but can turn the indoor cells into a usable network.