Patent ID: 8532135

Claim:
A method for performing a random access procedure in a wireless communication system, the method comprising: transmitting a preamble for random access from a mobile station to a base station; and receiving by the mobile station a random access response message from the base station as a response to the preamble, the random access response message having a MAC (Medium Access Control) header and zero or more MAC random access responses (RARs), wherein the MAC header comprises a MAC sub-header, wherein the MAC sub-header consists of 8 bits including a first bit directly followed by a second bit, and the MAC sub-header starts with the first bit, wherein the first bit indicates whether or not more fields are included in the MAC header, wherein the second bit indicates a backoff parameter, and wherein, when the second bit indicates the MAC sub-header has the backoff parameter, the random access response message has no MAC RAR.