No Room to Coexist

The best likely solution for LightSquared of Reston, Va., to operate its proposed wireless broadband network without interfering with the GPS signal in the United States is for the company’s network to occupy a different portion of the frequency spectrum than currently envisioned, said Gen. William Shelton, Air Force Space Command boss, Tuesday afternoon. “Of all the testing we have done and all of the analysis that we have done, there is really no way for GPS and LightSquared to co-exist for precision [GPS] receivers,” Shelton told attendees at AFA’s Air & Space Conference in National Harbor, Md. It’s true that developing a filter might keep the wireless network’s transmissions from disrupting the GPS signal for users of lower end GPS-capable devices like cell phones that don’t need high-end GPS accuracy, he said. However, for users of higher end GPS receivers that require the best possible signal reception for the highest accuracy, filters would drown out some of the GPS signal needed for that level of precision, he said. Shelton suspects more testing will be done to assess the effectiveness of the filters that LightSquared is proposing. “But looking into the crystal ball a little bit, I just don’t see any way other than spectrum reassignment,” he said.