Two U.S. Senators -- Pat Roberts of Kansas and Ben Nelson of Nebraska -- are asking colleagues to join them in urging the FCC to take all steps necessary to protect the Global Positioning System (GPS) from interference. The FCC's International Bureau recently gave conditional approval for a waiver to allow LightSquared Corporation to build a worldwide broadband network on frequencies immediately adjacent to those on which the GPS system operates. According to Newsline, some experts are concerned that the broadband network will swamp GPS signals and make the navigation system unusable, while others claim that interference will be minimal or non-existent. The senators' letter urges the FCC to require that LightSquared "objectively deomonstrate non-interference to GPS signals" as a condition of final approval for its operation.