摘要 |
A mobile station (UE) is configured to notify, to a radio base station (eNB), a preamble for RACH included in an uplink synchronization request transmitted by the radio base station by using an asynchronous RACH; notify, to the radio base station (eNB), the preamble, when failing to receive a TA command transmitted by the radio base station (eNB); and release the preamble, when a validity period of the preamble is passed. |