Patent ID: 7339921

Claim:
A connection identification (CID) allocating method in a Broadband Wireless Access (BWA) communication system having a medium access control protocol data unit (MAC PDU) format comprised of a header field including control information and a payload field including user data, wherein the header field comprises; a first CID field having a first length and indicating a CID of a mobile subscriber station (MSS), a second CID field having a second length and indicating the CID of the MSS by being concatenated with a CID of the first CID field according to a predetermined control, and a type field indicating whether the second CID field is used, the method comprising the steps of: generating an MSS CID to be allocated to a particular MSS; and if a length of the MSS CID is equal to the first length, including the MSS CID in the first CID field, including, in the type field, information indicating that the second CID field is not used, and transmitting the MAC PDU to the MSS.