GPS INTERFERENCE

ASA Position

ASA supports the FCC’s decision to prohibit LightSquared from developing its network, which showed significant interference with GPS usage. ASA supports the pursuit of expanded broadband coverage that will better connect rural communities while protecting the value of precision agricultural GPS systems.

Background

With more than a billion users worldwide, GPS is an integral part of daily life. The U.S. government has invested more than $35 billion in GPS constellation and systems, and continues to invest $1 billion more each year. Farmers use GPS to reduce waste in chemical and fuel use. Location information is collected by GPS receivers for mapping field boundaries, roads, irrigation systems, and problem areas in crops such as weeds or disease. GPS allows farmers to accurately navigate to specific locations in the field, year after year, to collect soil samples or monitor crop conditions.

In January 2011, the FCC gave conditional approval to LightSquared to build tens of thousands of ground stations. The radio wave spectrum LightSquared planned to use for its system sits in what is known as the L-Band, which is adjacent to the spectrum which GPS devices use. Because LightSquared's system would broadcast that spectrum from a network of terrestrial base stations as well as its satellite, its signals would be much stronger than the GPS signals in use on tractors, as well as other GPS units.

Serious concerns have been raised by many Government agencies about GPS interference, including the Departments of Defense, Transportation, and Homeland Security. Sixty-six representatives and 33 senators co-signed letters to the FCC supporting the uninterrupted operation of GPS.

In June 2012, LightSquared, recognizing the widespread problems with GPS interference, announced that they would develop an alternative deployment plan focused on a lower block of spectrum. According to their website, “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.” This alternative plan appears to be unworkable for many GPS applications, including high precision applications.

After conducting additional testing, the FCC announced in February that because there is no practical way to mitigate potential interference at this time, it will not lift the prohibition on LightSquared.