Government says LightSquared's 4G causes GPS interference
updated 09:30 pm EST, Fri December 9, 2011
Company claims report 'incomplete,' will fight on
The ongoing battle between LightSquared, a company that wants to launch a nationwide 4G (LTE) network in partnership with Sprint, and the rest of the GPS industry took another turn today as a leaked draft of a government report concludes that implementing LightSquared's planned network would cause "harmful interference" to about 75 percent of GPS receivers, BusinessWeek reports. The testing contradicts LightSquared's claim that it had found a fix for the issue.
The finding will almost certainly result in more delays for LightSquared as it struggles to bring its vision of a low-cost alternative 4G carrier to fruition. The company has consistently maintained that the actual problem is that GPS device manufacturers have failed to filter their devices for years (despite getting government tax breaks and other incentives for the industry), resulting in millions of devices that are prone to interference from other systems that use bandwidth close to the frequencies the GPS devices are supposedly limited to. LightSquared won the former satellite frequencies in a FCC auction.
This amount, argues LightSquared, to "bandwidth squatting." It has demanded that the GPS industry pay the company to come up with a comprehensive solution, to the tune of $400 million. Critics have pointed out that part of the problem actually lies with the FCC, which granted LightSquared waivers and authorizations to build a terrestrial network based on ground-level base stations, but using bandwidth which had been reserved for satellites, thus creating the issue of LightSquared's frequencies coming to close to those used by GPS providers.
LightSquared has already said that it would like to move to a different set of frequencies that are less likely to be so problematic, but cannot until the FCC approves the use of new spectrum, a process that would take years. In the meantime, it wants to go ahead with plans to use the bandwidth it paid for, and put the onus on the GPS industry to retrofit or recall equipment that would be affected by interefence.
The 4G company wants to build some 40,000 base stations around the US in addition to the towers and facilities it would lease from Sprint, offering mobile internet to as many as 260 million of the country's 312 million people. LightSquared vice president Martin Harriman says the company now plans to operate the base stations at a lower power level than was used during the tests, but this would still affect some 10 percent of existing GPS devices by his own estimate. The company had previously said that only half a percent -- about half a million GPS units -- would be affected by the LTE network if they were not equipped with special filters developed by LightSquared.
The government's tests, conducted from the end of October to early November, were so conclusive that it did not see the need or point for additional tests. "LightSquared signals caused harmful interference to a majority of GPS receivers tested," the report said. The tests, performed by the National Space-Based Positioning, Navigation and Timing (PNT) Systems Engineering Forum, found that 69 out of 92 receivers experienced "harmful" interference at a range of 100 meters (109 yards) from a LightSquared base station. It will formally present its findings on Dec. 14th in Washington, D.C.
LightSquared has fired back at the report's findings, saying that the tests used an "extraordinarily conservative" threshold and that the company was "outraged" by the illegal leak of "incomplete" government data. It pointed out that government testing of high-precision GPS equipment, such as those used in farm equipment and scientific instruments, would not begin until next year. Auto and boat navigation devices were primarily tested in the first round, it argued, and they are more prone to interference. [via BusinessWeek]
