US Patent 9867178 Base station signaling in a wireless network

A serving base station transmits to a target base station a first message comprising a parameter indicating whether a wireless device supports an enhanced physical downlink control channel (ePDCCH). The serving base station receives from the target base station a second message comprising parameters indicating: a configuration of a subset of subframes in which first radio resources of a first ePDCCH are configured; and a starting OFDM symbol of the first ePDCCH in the subset of subframes. The serving base station transmits a third message to the wireless device comprising the configuration information of the first ePDCCH.