Patent ID: 8830982

Claim:
An uplink control method for use in a communication system including a base station and a user terminal, wherein the base station communicates with the user terminal using multiple carriers including one or more primary carriers and one or more secondary carriers, the one or more primary carriers and the one or more secondary carriers each using a separate fast Fourier transform and radio frequency module to operate with an individual frequency band and frame structure, the method comprising: configuring, by the base station, different types of random access channels for different types of uplink operations by the user terminal; allocating, by the base station, the different types of random access channels for the different types of uplink operations to be transmitted on the multiple carriers; configuring a periodic random access channel for the user terminal to perform periodic uplink synchronization; allocating the periodic random access channel to each of the primary and secondary carriers; and transmitting, on the one or more primary carriers and the one or more secondary carriers, the periodic random access channel at least once in each of a plurality of super-frames, wherein initial uplink synchronization, handover and bandwidth request are performed only on the primary carriers.