Ligado Talking 3-Part TLPS 'Conformance' Plan With FAA

Ligado -- under fire from segments of the aviation and aeronautics industry worried about effects of its proposed LTE network on aviation GPS receivers (see 1608010036) -- agreed with some of their assertions. The company in a filing in FCC RM-11681 Tuesday said it had regular talks with Federal Aviation Administration staff about "performance-based conformance" conditions, such as the FAA and FCC requiring the company assess technical parameters of each base station before deployment to set power limits that would ensure conforming with FAA requirements. Ligado said the FAA is reviewing a Ligado-proposed model and compliance plan. The FAA didn't comment Tuesday. The company agreed with a process being pushed by the aviation industry that needs to be at least partially implemented before any granting of the firm's license modification or issuing of a related NPRM. Ligado said the conformance condition it's discussing with the FAA "is similar in many respects" to an aviation industry-backed three-step process outlined in an ex parte filing last week, which involves an FAA-headed theoretical investigation of possible Ligado interference to certified GPS receivers, field testing using real-world Ligado equipment, and deployment of Ligado's network -- with FAA- and FCC-imposed license conditions; rollout would be suspended if any interference issues manifest. At a meeting with Phil Verveer, aide to FCC Chairman Tom Wheeler, aviation groups complained Ligado didn't provide sufficient procedural and technical information, saying Ligado's push for approval should be shelved. Representatives of Aviation Spectrum Resources, Helicopter Association International, Airlines for America and the Aerospace Industries Association attended the meeting. They didn't comment Tuesday. The plan Ligado said it pitched to the FAA would have that agency -- with input from the Radio Technical Commission for Aeronautics -- OK a theoretical model the firm would use to predict signal propagation from proposed base stations. Field testing would follow to validate compliance of actual emissions with those modeled limits if the FAA and RTCA deem it necessary, to be followed by tower-by-tower assessment of the network deployment to ensure each base station follows power limits that would ensure received power from Ligado operations falls below FAA guidelines. Ligado said since it would have to satisfy all FCC conditions before bringing any part of terrestrial low-power service online, "there is therefore no reason to delay modifying Ligado's licenses subject to the conditions." The company said conditions suggested in its license modification application (see 1512310016) cover GPS interference protections, including some for certified aviation receivers. Those conditions would have the company reduce power in transmitters in the 1526-1536 MHz band to a level that would protect certified aviation receivers.