US Patent 8427976 Carrier information exchange between base stations

A first base station receives an application protocol message from a second base station. The second base station communicates employing at least one backward compatible carrier and at least one non-backward compatible carrier. The application protocol message comprises a identifier of the second base station, cell identifiers, and information identifying a carrier type. The base station operates a wireless device handover based, at least in part, on information in the second application protocol message.