Previewing a report to be filed with the FCC later this month, LightSquared LLC acknowledged on Wednesday that initial tests of the company’s terrestrial base stations operating in ancillary terrestrial component (ATC) bands authorized for mobile satellite service (MSS) use demonstrated some interference to adjacent global positioning satellite (GPS) operations. Formed last year from Harbinger Capital’s acquisition of MSS provider SkyTerra, LightSquared is in the process of deploying a nationwide mobile broadband network that would provide terrestrial, as well as satellite-based, coverage to more than 100 million potential customers by the end of next year. The company was granted a waiver of the FCC’s rules last January to permit standalone terrestrial wireless use of the company’s ATC spectrum, which is intended to support MSS services. However, at the behest of GPS and other adjacent spectrum users that fear potential interference from the LightSquared system, the FCC conditioned waiver approval upon LightSquared’s participation in a working group, consisting of representatives of the GPS community, that would test the effects of LightSquared’s operations on GPS receivers. The group is required to file its report with the FCC by June 15, and the FCC has barred LightSquared from launching commercial network operations until all interference concerns are resolved. In a statement, LightSquared executive vice president Jeff Carlisle said recent tests of base station transmitters operating in New Mexico “knocked out” some GPS operations in surrounding areas. Documents filed with the FCC by Deere & Co. point to “severe interference to Deere’s high-precision” GPS receivers from a distance of 22 miles and “complete loss of service” at proximities between four and 22 miles. Although Deere warned that its “customers in agriculture, construction and other applications will lose high accuracy navigation in and near areas served by LightSquared,” Carlisle maintained that his company is “open to the full range of possible solutions” as “our network and GPS can coexist.”