WIRELESS COMMUNICATIONS SYSTEM AND METHOD

摘要

A wireless communications system is described which comprises a base station, a relay device, and a terminal device. The terminal device is operable to transmit one or more access request messages of a first type to request uplink resources from the base station, and if no response to the transmitted access request messages of the first type is received from the base station, to transmit an access request message of a second type. The base station is responsive to an access request message of the first type received from the terminal device to transmit an allocation of uplink resources to the terminal device. The relay device is responsive to an access request message of the second type received from the terminal device to transmit a relayed access request message to the base station to request the base station to allocate uplink resources to the terminal device. The base station is responsive to the relayed access request message from the relay device to transmit an allocation of uplink resources to the terminal device. This modified random access procedure for an uplink-only relay system enables the relay device to readily identify those terminal devices which cannot be served directly by the base station (because they have already tried and failed to reach the base station via the first type of access request message).