LightSquared’s regulatory woes won’t go away, with the Wall Street Journal reporting that US defense department and federal transportation officials are expressing concern that its proposed LTE service will interfere with GPS devices vital to military operations and aviation safety, and they are calling for a “comprehensive” study of the issue. This is not the first time the GPS issues have been discussed. In January it was reported that LightSquared sent a letter to the US Federal Communications Commission, intended to address previously-reported concerns that its hybrid LTE/satellite network could cause interference with existing systems – including GPS receivers.