Broadband threat to GPS accuracy

A coalition of leading manufacturers, contractors and associations from various industries called the 2625 Transportation Construction Coalition (TCC) has sent an open letter to US Secretary for Transporation, Ray LaHood, expressing concerns over a major threat to GPS signal accuracy. The issue relates to a proposed broadband network from 2628 LightSquared, which is thought to pose a risk to GPS accuracy.

The TCC is asking LaHood to block the 2115 Federal Communications Commission from considering the broadband network. According to the TCC, multiple testing reports on the LightSquared proposal indicate widespread interference with Global Positioning Systems (GPS) signals. GPS technology has become critical to improving the productivity, efficiency and safety on construction job sites.

Increasingly, the technology is used to map and survey construction sites including the location of buried and overhead utilities, allow precision grading and enhance material application. It is also used to prevent theft of construction equipment, and provide real]time monitoring for equipment maintenance.

The 2627 Association of Equipment Manufacturers (AEM) is a founding member of the TCC and points out that the economic cost to US industry (agriculture as well as construction) could be as high as US$96 billion. According to one AEM-member company, the LightSquared plan could degrade most if not all GPS receivers as far as 35km from one of the 40,000 transmitters.

The TCC letter also makes it clear that “We do not object to the goals of increasing wireless data capacity and competition but the available test data has shown overwhelming interference, and LightSquared should not be allowed to launch in the spectrum adjacent to GPS and jeopardise construction operations.”

This GPS technology helps improve worker safety, reduces project delays, reduces fuel consumption and produces a more efficient worksite. Any interference with these signals would be extremely disruptive to the many benefits GPS has brought to construction sites. The TCC does not object to the goals of increasing wireless data capacity and competition but it claims that test data has shown overwhelming interference, and LightSquared should not be allowed to launch in the spectrum adjacent to GPS and jeopardise construction operations.

The TCC coalition said that “Increasingly, the technology is used to map and survey construction sites including the location of buried and overhead utilities, facilitate precision grading and enhance material application. It is also used to prevent theft of construction equipment, and provide real-time monitoring for equipment maintenance. This GPS technology helps improve worker safety, reduces project delays, reduces fuel consumption and produces a more efficient worksite. Any interference with these signals would be extremely disruptive to the many benefits GPS has brought to construction sites.”

The TCC is a partnership of 29 national associations and construction unions representing hundreds of thousands of individuals with a direct market interest in federal transportation programs. TCC member organisations represent contractors, the planning and design community, materials and manufacturing industries, and their employees. The TCC is urging LaHood's active engagement to protect GPS use in the construction and transportation sectors.