Patent ID: 8520497

Claim:
A method comprising: a) receiving, by a wireless device, at least one radio resource control message from a base station, said at least one radio resource control message: i) causing configuration of a plurality of carriers comprising a first carrier and a plurality of additional carriers in said wireless device; and ii) comprising a carrier group index for a carrier in said plurality of carriers, said carrier group index identifying a carrier group, said carrier group being one of a plurality of carrier groups, said plurality of carrier groups comprising: (1) a first carrier group comprising a first subset of said plurality of carriers, said first subset comprising said first carrier, uplink transmissions by said wireless device in said first carrier group employing a first synchronization signal received from said base station on said first carrier as a first timing reference; and (2) a second carrier group comprising a second subset of said plurality of additional carriers; b) transmitting first uplink signals in said second carrier group, by said wireless device, employing a first additional carrier as a timing reference carrier, said first additional carrier being an activated carrier in said second carrier group; c) changing, autonomously by said wireless device, said timing reference carrier to a second activated additional carrier in said second carrier group in response to deactivation or release of said first additional carrier and when at least one additional carrier in said second carrier group is active; d) transmitting second uplink signals in said second carrier group, by said wireless device, employing a second synchronization signal received from said base station on said second activated additional carrier as a second timing reference; e) receiving, by said wireless device from said base station, at least one time alignment command, said time alignment command comprising: i) a time adjustment value; and ii) an index identifying said first carrier group or said second carrier group; and f) applying, by said wireless device, said time adjustment value to third uplink signals transmitted on all activated uplink carriers in one of said first carrier group or said second carrier group identified by said index.