WASHINGTON-A coalition of government agencies including the Coast Guard, the Federal Highway Administration and the Air Force are in the process of building a system that will increase the accuracy of the global positioning system from 50 meters to one to three meters, said James A. Arnold, an engineer in the FHA’s Office of Operations Research and Development.
Arnold spoke about deferential GPS at a meeting last week of the Wireless Innovations in Communications Initiative.
Accuracy problems with the regular GPS system are caused by a variety of errors inherent in the GPS system, such as the exact position of the satellite and its timing, said Arnold.
Currently, deferential GPS covers land areas near bodies of water, but inland areas are not covered. The interagency group hopes to cover the rest of the populated areas of the nation by the end of the year, said Arnold.
Obtaining the signal from the deferential GPS system is free, but users first must buy a receiver that integrates the beacon technology with GPS. The cost of the receivers begins at about $500, said Arnold.
The deferential GPS signal could be useful as wireless carriers look toward the Oct. 1 deadline for reporting to the Federal Communications Commission on which method they plan to use to implement enhanced 911 Phase II rules. Current FCC rules were based on pre-deferential statistics so they only require an accuracy of 50 meters, two-thirds of the time for handsets. With deferential GPS technology, greater accuracy is possible.
Qualcomm Inc. has advocated an accuracy rate of five meters, said Louis Pineda, Qualcomm vice president for product management.
Pineda said Qualcomm uses a form of deferential GPS in its hybrid solution. The hybrid solution was first advocated by SnapTrack Inc. Qualcomm bought SnapTrack last year and last week announced it was spinning off the company.
Arnold’s WICI presentation also focused on other intelligent transportation service systems that use wireless technology such as dedicated short range communications. DSRC plans to use spectrum recently authorized by the FCC above 5 GHz to communicate with cars about road work zones and to perhaps someday eliminate the need for tollbooths.
Private vendors wishing to introduce solutions to the government to be used in intelligent transportation systems will make presentations at upcoming WICI meetings.
