LightSquared, the Philip Falcone-backed mobile broadband company, is teetering on the edge of bankruptcy. The company has been negotiating with lenders in recent days to restructure its debt and avoid defaults. According to the Wall Street Journal, however, it has been unable to reach such agreements. LightSquared has until 5PM today to resolve debt issues with its lenders. If it cannot, it will likely seek bankruptcy protection. LightSquared hoped to build a nationwide LTE mobile broadband network, but the Federal Communications Commission blocked the plan, citing interference issues with nearby GPS signals.