A terminal device is arranged to communicate with a base station via a relay device in a wireless communications system. The terminal device comprises: a transmitter arranged to transmit an access request message to the base station, wherein the access request message comprises one from a set of access preambles that indicate relay device uplink assistance is required; a receiver arranged to receive an access request grant response from the base station; and a control processor operably coupled to the transmitter and receiver and arranged to: process the access request grant response and determine from a timing advance part thereof transmit power control (TPC) information for transmitting to the base station via the relay device.