Apple's process for approving or rejecting applications for the iPhone has drawn wide criticism for being murky and unpredictable. Google Voice is a VoIP service that lets users set up one phone number and have it ring on all of their phones at once, and control which phones ring at which times of the day or week, among other things.
The rejection of Google Voice, and the removal from the App Store of third-party applications that use it, led some observers to suspect AT&T squelched the software because it feared competition for its own voice services. In its letter, the FCC cited pending proceedings at the agency regarding wireless open access and handset exclusivity.
The agency requested answers from all three companies by the close of business on Aug. 21.