Patent ID: 9288825
Filing Date: 2016-03-15
CPC Classification: H04W

Claim Text:
1. A method for performing random access in a user equipment (UE) of a mobile communication system, the method comprising: receiving system information indicating a group of identification(ID)s; selecting an first ID from among the group of the IDs; transmitting a first uplink signal corresponding to the selected first ID for random access to a Node B; after the transmitting of the first uplink signal, waiting for a predetermined delay duration without checking a downlink channel; after the waiting for the predetermined delay duration, checking the downlink channel during a valid period; determining whether a downlink signal responding to the first uplink signal is received in the valid period, the downlink signal comprising a second ID and an UE-ID; and transmitting a second uplink signal using the UE-ID, if the downlink signal is received during the valid period and the second ID is equal to the first ID, wherein the valid period starts when the predetermined delay duration starting from transmission of the first uplink signal has terminated.