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LightSquared says LTE network interference with GPS solved

LightSquared SkyTerra 1

For months, concerns have been brewing that LightSquared‘s forthcoming satellite-assisted 4G LTE network would interfere with GPS reception by positioning high-powered transmissions in frequency blocks adjacent to GPS signals—which are notoriously low-powered and subject to interference. Now, the company says it has devised a “comprehensive solution” to the problem, and plans to shift away from a 10MHz frequency block it planned to use to launch its service to another 10 MHz block further away from GPS frequencies, and has reached an agreement with Inmarsat—which controls the lower spectrum block—so it can continue to roll out its business plan on schedule.

“This is a solution which ensures that tens of millions of GPS users won’t be affected by LightSquared’s launch,” said LightSquared chairman and CEO Sanjiv Ahuja, in a statement. “At the same time, this plan offers a clear path for LightSquared to move forward with the launch of a nationwide wireless network that will introduce world class broadband service to rural and underserved areas which still find themselves on the wrong side of the digital divide.”

LightSquared’s deployment shift comes in the wake of concerns from everyone from the U.S. Air Force Space Command to the Department of Homeland Security that LightSquared’s plan to send high-powered transmissions from satellites to as many as 40,000 terrestrial base stations could overwhelm low-power GPS signals on adjacent frequencies. The concerns were not new, and LightSquared worked with the GPS industry and the National Telecommunications and Information Administration to test and approve its use of GPS-adjacent frequencies. However, LightSquared now acknowledges that “early tests” indicated that the frequency block where it planned to launch LTE service posed interference risk for “many” GPS receivers. However, the company’s test results with the new, lower block of frequencies generates almost no interference, with LightSquared claiming only high-precision receivers specifically designed to operate in LightSquared’s spectrum bring impacted.

No financial or other terms of LightSquared’s arrangement with Inmarsat were disclosed.

LightSquared’s LTE network is based on a fundamentally different design than traditional mobile broadband networks being constructed by the likes of Verizon Wireless, AT&T, and Sprint—instead of using fiber and Ethernet backhaul to interconnect towers and transmission points, LightSquared will use satellite transmission to link together base stations, eliminating the need to construct (or lease) expensive ground-based networks. In theory, LightSquared’s network could bring 4G LTE service to rural and outlying areas traditionally passed over by major broadband operators. The company plans to sell service to other wireless operators, rather than bring LTE directly to consumers. Leap Wireless and Best Buy are already onboard as partners.

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