LightSquared claims success for GPS tests
Results from Alcatel-Lucent labs indicate that high precision gadgets from three vendors are not disrupted by start-up's LTE signals
Published: 8 December, 2011
LightSquared has come out with its most concrete claims so far that its LTE network will not interfere with GPS services across the US. The start-up says an Alcatel-Lucent laboratory has carried out extensive tests on devices from three GPS vendors, whose preliminary results demonstrate that those devices are not disrupted by the LTE signals in nearby mobile satellite spectrum.
LightSquared CEO Sanjiv Ahuja told a news conference that the devices involved in the tests came from Javad GNSS, PCTel and Partron. The company's statement said it was now "well on its way" to demonstrating that GPS interference concerns have been resolved.
The GPS industry, which has been opposing LightSquared's bid to run LTE services in satellite bands close to GPS spectrum, is not convinced. "The results announced today do not address proven interference to hundreds of thousands of existing high precision GPS receivers in a wide variety of critical uses," said Jim Kirkland, general counsel of another GPS manufacturer, Trimble Navigation, who has been the key spokesperson for the anti-LightSquared lobby. His statement said the tests were "simply one input". Other opponents include shipping firms Fedex and UPS, the Air Transport Association and other device makers such as Garmin.
The FCC has a strong interest in green-lighting LightSquared's plan, which would create new sources of broadband capacity especially in underserved areas; additional competition; and would leverage the underused mobile satellite bands. However, its preliminary waiver, which allowed the start-up to run terrestrial-only wireless services in a satellite frequency, will only be confirmed if the GPS issue can be resolved. US officials are examining data from various tests, but have not given a deadline for making a final decision. Other carriers' plans hang on the result too, including those of Sprint, which has a provisional network hosting and spectrum sharing deal with the new company, and a host of wholesale customers including Leap Wireless and retailer Best Buy.
LightSquared has proposed various remedies to the GPS issue, including restricting its services to the area of its spectrum which is furthest from the navigation service bands. However, even this could still affect high precision devices used in transport and agriculture, so these are the focus of the ongoing rounds of tests, as well as development of possible filters to mitigate interference. There have been disputes over whether LightSquared, the GPS industry or the government should fund such filters.
The test results from Alcatel-Lucent will carry weight because of the vendor's deep experience of mobile satellite systems. However, it does have a commercial relationship with LightSquared - it agreed in 2009 to develop satellite base station subsystems for SkyTerra, now part of the new venture, and it is a key supplier to Sprint's Network Vision infrastructure, which will host the LightSquared LTE terrestrial RAN.