Reporting to the FCC last Friday, a working group studying the potential impact of LightSquared’s wireless network operations on global positioning system (GPS) users cited progress on testing activities. Meanwhile, a pair of U.S. senators called on the FCC to monitor closely the testing process “to ensure GPS is not compromised in any way.” Co-chaired by representatives of LightSquared and Trimble Navigation, the working group was mandated by the FCC as one of several conditions attached to a rule waiver granted by the agency earlier this year. That ruling permits mobile satellite service (MSS) provider LightSquared to lease its ancillary terrestrial component (ATC) spectrum to entities that would use those ATC channels to offer stand-alone terrestrial wireless broadband services to their customers. Responding to federal and commercial GPS users who fear that the proposed usage of LightSquared’s ATC spectrum would interfere with their operations, the FCC conditioned waiver approval upon LightSquared’s participation in a working group that would assess the level of potential interference to GPS networks. The FCC also barred LightSquared from commencing its proposed network operation until GPS interference issues are resolved. In its second progress report to the FCC last Friday, LightSquared and the U.S. GPS Industry Council noted that sub-teams focused on various uses of GPS “have been meeting regularly. The FCC will be notified next month of updates to current draft test plans and to the list of devices and receiver models to be tested, with the final progress report to be filed on June 15. Meanwhile, Senators Ben Nelson (D-NE) and Pat Roberts (R-KS) urged fellow senators in a “dear colleague” letter last Thursday to support their call for closer FCC supervision of the working group’s activities. Declaring, “the full Commission must be involved and require LightSquared to objectively demonstrate non-interference as a condition prior to any operation of the proposed service,” Nelson and Roberts stressed to their colleagues that “anything less is an unacceptable risk to public safety.” LightSquared executive vice president Jeff Carlyle replied: “we are confident these issues can be addressed and we will launch LightSquared’s commercial operations only when the current review process is completed to the FCC’s satisfaction.”