A method of performing random access at a user equipment in a wireless communication system using multiple carriers, the method comprising: transmitting a preamble for random access to a network to establish a radio resource control, RRC, connection with a network; receiving a random access response message from the network in response to the preamble, the random access response message comprising uplink resource allocation information and a temporary identifier of the user equipment; transmitting an RRC connection request message to the network through uplink resources allocated according to the uplink resource allocation information after receiving the random access response message, the RRC connection request message requesting connection establishment with the network, wherein the RRC connection request message comprises a first user equipment identifier; the method being characterized in that it further comprises: receiving control information from the network on a control channel, the control information comprising a second user equipment identifier and associated with receiving a RRC message receiving the RRC message comprising an RRC contention resolution message from the network using the control information if the second user equipment identifier is equal to the temporary identifier of the user equipment; and receiving, within the RRC message, an RRC connection setup message from the network in response to the RRC connection request message, wherein if the RRC connection setup message comprises the first user equipment identifier sent by the user equipment through the RRC connection request message, the user equipment considers the random access procedure to be successful and uses the temporary identifier of the user equipment as a private user equipment identifier, C-RNTI, for performing communications with the network. transmitting a preamble for random access to a network to establish a radio resource control, RRC, connection with a network; receiving a random access response message from the network in response to the preamble, the random access response message comprising uplink resource allocation information and a temporary identifier of the user equipment; transmitting an RRC connection request message to the network through uplink resources allocated according to the uplink resource allocation information after receiving the random access response message, the RRC connection request message requesting connection establishment with the network, wherein the RRC connection request message comprises a first user equipment identifier; receiving control information from the network on a control channel, the control information comprising a second user equipment identifier and associated with receiving a RRC message receiving the RRC message comprising an RRC contention resolution message from the network using the control information if the second user equipment identifier is equal to the temporary identifier of the user equipment; and receiving, within the RRC message, an RRC connection setup message from the network in response to the RRC connection request message, wherein if the RRC connection setup message comprises the first user equipment identifier sent by the user equipment through the RRC connection request message, the user equipment considers the random access procedure to be successful and uses the temporary identifier of the user equipment as a private user equipment identifier, C-RNTI, for performing communications with the network.