Patent ID: 8488443

Claim:
A method of handling a radio link failure in a multiple-carrier system performed by a user equipment (UE), the method comprising: receiving data from a base station (BS) by using a plurality of carriers including a first carrier and a second carrier; detecting a first radio link problem for the first carrier; determining whether the first carrier is an extension carrier which does not carry a physical downlink control channel (PDCCH); if the first carrier is not the extension carrier, starting a first timer for the first carrier, wherein the first timer is not started if the first carrier is the extension carrier; transmitting, to the BS, a first message indicating the first radio link problem for the first carrier via uplink resource of the second carrier upon expiry of the first timer; detecting a second radio link problem for the second carrier; determining whether the second carrier is the extension carrier; if the second carrier is not the extension carrier, starting a second timer for the second carrier, wherein the second timer is not started if the second carrier is the extension carrier; transmitting, to the BS, a second message indicating the second radio link problem for the second carrier upon expiry of the second timer; starting a final timer, if radio link problems in all of the plurality of carriers are detected; and transmitting, to the BS, a final message requesting a connection re-establishment upon expiry of the final timer, wherein the first carrier and the second carrier are aggregated.