Feds look beyond LightSquared to set GPS interference standards

A top transportation official wants rules to prevent interfering uses in the future

A high-ranking federal official and aviation industry leaders called on Wednesday for rules to prevent future interference with GPS, looking beyond a proposal by would-be hybrid mobile operator LightSquared that may be doomed by broad opposition.

LightSquared's proposed cellular data network can't be made compatible with GPS, and the government should set interference standards to prevent future conflicts over companies trying to establish such services, Deputy Transportation Secretary John Porcari told a House Aviation Subcommittee hearing on Wednesday.

Porcari, who co-signed a letter last month that ruled out solving interference issues between the two systems in the coming months or years, repeated that assertion at the hearing and gave more details of the reasoning behind it.

The National Space-Based Positioning, Navigation and Timing Executive Committee (PNT ExComm), which Porcari co-chairs with a deputy secretary of defense, has effectively dismissed LightSquared's proposal. PNT ExComm represents eight federal departments and the Joint Chiefs of Staff. However, the Federal Communications Commission has the ultimate authority to squash the carrier's plan or let it go forward.

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A high-ranking federal official and aviation industry leaders called on Wednesday for rules to prevent future interference with GPS, looking beyond a proposal by would-be hybrid mobile operator LightSquared that may be doomed by broad opposition.

LightSquared's proposed cellular data network can't be made compatible with GPS, and the government should set interference standards to prevent future conflicts over companies trying to establish such services, Deputy Transportation Secretary John Porcari told a House Aviation Subcommittee hearing on Wednesday.

Porcari, who co-signed a letter last month that ruled out solving interference issues between the two systems in the coming months or years, repeated that assertion at the hearing and gave more details of the reasoning behind it.

The National Space-Based Positioning, Navigation and Timing Executive Committee (PNT ExComm), which Porcari co-chairs with a deputy secretary of defense, has effectively dismissed LightSquared's proposal. PNT ExComm represents eight federal departments and the Joint Chiefs of Staff. However, the Federal Communications Commission has the ultimate authority to squash the carrier's plan or let it go forward.

LightSquared wants to build an LTE (Long-Term Evolution) network that uses frequencies next to the band assigned to GPS. It would form half of a system that would also include a satellite network, and the company would sell each to carriers at wholesale. The FCC conditionally approved the LTE network plan in January 2011 as part of its push to open up an additional 500MHz of spectrum to mobile broadband. The agency said any interference issues would need to be resolved before LightSquared could launch the network.

Porcari and other speakers, including representatives from GPS vendor Garmin and the industry groups Airlines for America, called for a coordinated effort among government agencies to prevent future interference with GPS by other services. His own proposal calls for the National Telecommunications and Information Administration and PNT ExComm to set standards for what uses would be allowed in adjacent spectrum bands. The proposals would be communicated to all affected parties, including potential new users of spectrum.

"Establishing those standards would give them a good sense of what kind of uses would be compatible and which would not," Porcari said.

In his testimony, Porcari repeated PNT Excom's conclusion that no more tests of LightSquared's system were warranted after the last round, in November, showed that 75 percent of tested general-navigation GPS devices received harmful interference from the LTE transmissions. The federal government spent substantial funds, including US$2 million from the Federal Aviation Administration, on tests of commercial GPS gear such as phones and car navigation devices and on avionics systems, he said.

"Due to the Administration's commitment to increase access to broadband, the investment was merited, but given the results we reviewed, further investment cannot be justified at this time," Porcari wrote.

The IDG News Service is a Network World affiliate.