A relay device (205, 305, 420) in a mobile communications network, the relay device being configured to communicate with a terminal device (203, 204, 303, 430) of the network and with a base station (201, 301, 410) of the network, the relay device comprising: transmitter circuitry configured to transmit signals to the terminal device and to transmit signals to the base station, receiver circuitry configured to receive signals from the terminal device and to receive signals from the base station, and controller circuitry configured in combination with at least the transmitter circuitry: to select a maximum transmission power to be used by the terminal device for communicating with the relay device, wherein the selected maximum transmission power is based on link information relating to one or both of the link between the relay device and the base station and the link between the relay device and the terminal; to notify the terminal device of the selected maximum transmission power for the terminal device to select an actual transmission power and to transmit signals to the relay device at a power that is no more than the maximum transmission power, wherein the controller circuitry is configured in combination with at least the transmitter circuitry: to notify the terminal device by transmitting signals to the terminal device based on one or more of: (i) a received power for said signals and (ii) transmitting an indicator to the terminal device and notifying the terminal device of the transmission power used by the relay device for said signals. transmitter circuitry configured to transmit signals to the terminal device and to transmit signals to the base station, receiver circuitry configured to receive signals from the terminal device and to receive signals from the base station, and controller circuitry configured in combination with at least the transmitter circuitry: to select a maximum transmission power to be used by the terminal device for communicating with the relay device, wherein the selected maximum transmission power is based on link information relating to one or both of the link between the relay device and the base station and the link between the relay device and the terminal; to notify the terminal device of the selected maximum transmission power for the terminal device to select an actual transmission power and to transmit signals to the relay device at a power that is no more than the maximum transmission power, wherein the controller circuitry is configured in combination with at least the transmitter circuitry: to notify the terminal device by transmitting signals to the terminal device based on one or more of: (i) a received power for said signals and (ii) transmitting an indicator to the terminal device and notifying the terminal device of the transmission power used by the relay device for said signals. to select a maximum transmission power to be used by the terminal device for communicating with the relay device, wherein the selected maximum transmission power is based on link information relating to one or both of the link between the relay device and the base station and the link between the relay device and the terminal; to notify the terminal device of the selected maximum transmission power for the terminal device to select an actual transmission power and to transmit signals to the relay device at a power that is no more than the maximum transmission power, wherein the controller circuitry is configured in combination with at least the transmitter circuitry: to notify the terminal device by transmitting signals to the terminal device based on one or more of: (i) a received power for said signals and (ii) transmitting an indicator to the terminal device and notifying the terminal device of the transmission power used by the relay device for said signals.