Patent ID: 7876782

Claim:
A method of constructing a medium access control protocol data unit to be transmitted through a common transport channel in a mobile communication system, the method comprising: transmitting a request message to a network to enter idle mode; receiving an user equipment identifier type indicator and a data packet from an RLC layer, wherein the user equipment identifier type indicator is transmitted from an RRC layer and is used to indicate one among two or more user equipment identifier types, and the data packet is received through a dedicated logical channel; adding a target channel type field (TCTF), the user equipment identifier type indicator, and a user equipment identifier for identifying a user equipment to the data packet in order to construct the medium access control protocol data unit, wherein the user equipment identifier is used to identify a user equipment and is determined based on the user equipment identifier type indicator, and the target channel type field (TCTF) indicates identification of a logical channel class on a common transport; and transmitting the medium access control protocol data unit to a physical layer through the common transport channel.