Disclosed is a wireless transmitting/receiving unit (WTRU), which is used for transmitting the random access request to the base station on the uplink RACH front synchronous code. The RACH response transmitted by the base station is received by each WTRU. The RACH responded control signal part indicates the position of the RACH response message part. The RACH responded control signal comprises a plurality of control channel element(CCE), wherein, the respective CCE is distributed for each WTRU to provide the only RACH response control signal. The WTRU is configured into the predetermined CCE for positioning the WTRU in the plurality of CCEs transmitted from the base station.