If the government gave the green light for a nationally adopted 4G network it could very well be at the cost of GPS receivers. This is according to initial tests carried out by the Department of Defense, FAA and select GPS device manufacturers there were obtained by Bloomberg News. These studies showed this type of broadband service affected the performance of 75 percent of all GPS receivers tested. The $14-billion network has been planned and proposed by LightSquared, which creates open wireless broadband networks. LightSquared’s proposal also included an additional 40,000 towers nationwide. GPS industry experts quickly spoke out on these new towers through its  "Coalition to Save Our GPS" analysis. It argued these towers could result in “tens of thousands [of] 'dead spots'–each miles in diameter–throughout U.S. cities where there was a LightSquared transmitter." For its part, LightSquared told Bloomberg it was outraged these testing results had been released prematurely, leading many to draw “an inaccurate conclusion to negatively influence the future of LightSquared and narrowly serve the business interests of the GPS industry.” The full report will be presented in Washington, D.C., on Dec. 14.