Patent ID: 8446844

Claim:
A method comprising: a) receiving, by a serving base station configured to communicate employing at least one backward compatible carrier and at least one non-backward compatible carrier, a first message from a wireless device on a primary carrier in said at least one backward compatible carrier, said first message comprising one or more parameters implicitly or explicitly indicating whether said wireless device supports configuration of one or more non-backward compatible carriers, a first common reference signal overhead of each of said at least one non-backward compatible carrier being lower than a second common reference signal overhead of each of said at least one backward compatible carrier; b) transmitting, by said serving base station to said wireless device, at least one second message, at least some parameters in said at least one second message depend at least in part on said first message, said at least one second message: i) comprising: (1) an identifier for each carrier in said plurality of carriers, said plurality of carriers comprising: (a) at least one of said at least one backward compatible carrier; and (b) at least one of said at least one non-backward compatible carrier; (2) information identifying a carrier type for each of said plurality of carriers, said carrier type being one of a backward compatible type and non-backward compatible type; (3) information associating each non-backward compatible carrier in said plurality of carriers with one backward compatible carrier in said plurality of carriers; and (4) measurement parameters; and ii) configured to cause: (1) configuration of a plurality of carriers in said wireless device; and (2) said wireless device measuring signal quality of at least one carrier of one or more target base stations in response to said measurement parameters; and c) receiving, by said serving base station, at least one measurement report from said wireless device in response to said at least one second message, said at least one measurement report comprising signal quality information of at least one of said at least one carrier of at least one of said one or more target base stations, said signal quality information derived at least in part employing measurements of at least one OFDM subcarrier; d) making a handover decision, by said serving base station, based at least in part on said at least one measurement report; and e) transmitting, by said serving base station, in response to said serving base station making a handover decision for said wireless device, at least one third message to at least one target base station, said at least one third message comprising at least one of: i) said one or more parameters indicating whether said wireless device supports configuration of one or more non-backward compatible carriers; and ii) configuration information of said at least one of said at least one non-backward compatible carrier.