SAN FRANCISCO — Qualcomm has developed technology to run LTE Advanced (LTE-A) over the 5 GHz band to address an expected 1,000x increase in mobile data traffic. The move is an early shot in what may be a battle between cellular and WiFi over the unlicensed spectrum.
The Qualcomm technology is so far just a prototype with no announced plans for products supporting it. Nevertheless, it raises the question of how best to use the 5 GHz band to handle a rising tide of mobile data, most of it carried today on cellular services operating in sub-3 GHz licensed bands.
Vendors including Qualcomm's Atheros division are selling multiple WiFi products operating at 5 GHz. Some vendors may use 5 and even 60 GHz links on an emerging class of small-cell cellular base stations. And researchers working on next-gen cellular technologies are exploring cellular services on everything from 5 to 60 GHz.
“The foundation [for more data] is more small cells everywhere, new deployment models, and more low-cost ways of deploying,” says Rasmus Hellberg, senior director of technical marketing for Qualcomm. “Unlicensed [spectrum] is ideal for automatic mobility... [and LTE-A] works better with more nodes because it can bring coordinated scheduling and synchronization between nodes to help provide performance when it becomes crowded.”
Hellberg says LTE-A over unlicensed spectrum is superior to carrier WiFi due to its longer range, “controlled and robust reliability,” and seamless end-user experience. In addition, he added, mobile operators could benefit from a unified cellular service.
LTE over unlicensed spectrum "works just as carrier aggregation does today. The main thing is to get support for the frequency band where a license is -- there is 500 MHz of spectrum available in 5 GHz.”
A diagram of a unified licensed and unlicensed spectrum, using LTE Advanced.
Although Qualcomm made no commitment on product availability, the LTE-A capability will be integrated into future SOCs, Hellberg told us. The announcement may be too early as such integration is three to five years off, says analyst Jack Gold.
“I think what you’re going to see happen is that next-generation wireless protocols are going to start converging,” says Gold, president and principal analyst of J. Gold and Associates. “Qualcomm tends to talk about things well in advance of when they’re practical. The biggest problem is legacy equipment in place that may not be compatible with what they’re trying to achieve.”
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