GPS Interference Issue Continues

Cindy ZimmermanGPS

A company planning to provide a wireless broadband/satellite network claims to have solved a GPS interference issue, but a new study finds interfering with GPS signals could cost the economy.

Officials with the Virginia-based company LightSquared, which wants to set up 40,000 wireless broad-band stations across the nation on a frequency that is right next to the one used by GPS, have outlined a proposal they say will address the problem of interference.

Early test results indicated that one of LightSquared’s 10MHz blocks of frequencies poses interference to many GPS receivers. This block happens to be the specific set of frequencies that LightSquared planned to use for the initial launch of its nationwide wireless broadband network.

Based on those same early test results, LightSquared determined that another 10MHz block of the spectrum did not create such an interference risk. This block is lower on the spectrum band and located further away from the GPS frequencies, greatly reducing the risk for interference.

Test results show this lower block of frequencies is largely free of interference issues with the exception of a limited number of high precision GPS receivers that are specifically designed to rely on LightSquared’s spectrum. In its original plan, LightSquared planned to move into this other frequency block as its business grew over the next two to three years.

Agricultural interests are concerned about that exception. A study released by the Coalition to Save Our GPS, which includes several agricultural technology companies, estimates that LightSquared’s plan could result in “direct economic costs of up to $96 billion to U.S. commercial GPS users and manufacturers.” Jim Kirkland, vice president and general counsel of Trimble, says the analysis “also highlights how LightSquared’s recently announced ‘solution’ to the interference problem, which LightSquared admits will not reduce interference for high precision GPS uses, is no solution at all. High precision GPS uses represent nearly $ 10 billion in historical investment by GPS users over the last five years and $30 billion in annual economic benefits.”

“The use of GPS technology is vital to thousands of people who make their living with agricultural and construction equipment. It is simply not acceptable to allow this new network to interfere with these important industries when all indications are that there is no practical solution to mitigate this interference,” said Ken Golden, director of global public relations at John Deere. “In agriculture, the loss of a stable GPS system could have an impact of anywhere from $14 to $30 billion each year. That could significantly erode the strong competitive global position of U.S. farmers in the world agricultural economy.”

Meanwhile, the 2012 agriculture appropriations bill recently passed by the House includes language specifically to register concerns about the LightSquared network and directs the USDA “to ensure the FCC is aware of these concerns.”