A terminal device for use with a wireless telecommunications system, the terminal device comprising: a transmitter; a receiver configured to receive a measurement radio signal from each of a plurality of potential relay nodes of the wireless telecommunications system, each measurement radio signal being encoded using a different respective code in accordance with a code-division multiplexed, CDM, configuration and transmitted using the same common predetermined radio frequency band and identifying the one of the potential relay nodes from which it is transmitted; and a controller configured: to measure a characteristic of each received measurement radio signal indicative of the suitability of the potential relay node associated with that measurement radio signal for acting as a relay node for relaying a further radio signal between the terminal device and infrastructure equipment of the wireless telecommunications system, and based on each received measurement radio signal and its measured characteristic, to determine a suitable one of the plurality of potential relay nodes for acting as a relay node for relaying the further radio signal between the terminal device and the infrastructure equipment, and to control one of the transmitter to transmit the further radio signal to the infrastructure equipment via the determined relay node and the receiver to receive the further radio signal from the infrastructure equipment via the determined relay node; wherein the common predetermined radio frequency band is a predetermined narrowband with a bandwidth defined by that of a predetermined number of physical resource blocks, PRBs, adjacent to each other in the frequency domain, the predetermined narrowband being only for the transmission of the measurement radio signals. a transmitter; a receiver configured to receive a measurement radio signal from each of a plurality of potential relay nodes of the wireless telecommunications system, each measurement radio signal being encoded using a different respective code in accordance with a code-division multiplexed, CDM, configuration and transmitted using the same common predetermined radio frequency band and identifying the one of the potential relay nodes from which it is transmitted; and a controller configured: to measure a characteristic of each received measurement radio signal indicative of the suitability of the potential relay node associated with that measurement radio signal for acting as a relay node for relaying a further radio signal between the terminal device and infrastructure equipment of the wireless telecommunications system, and based on each received measurement radio signal and its measured characteristic, to determine a suitable one of the plurality of potential relay nodes for acting as a relay node for relaying the further radio signal between the terminal device and the infrastructure equipment, and to control one of the transmitter to transmit the further radio signal to the infrastructure equipment via the determined relay node and the receiver to receive the further radio signal from the infrastructure equipment via the determined relay node; wherein the common predetermined radio frequency band is a predetermined narrowband with a bandwidth defined by that of a predetermined number of physical resource blocks, PRBs, adjacent to each other in the frequency domain, the predetermined narrowband being only for the transmission of the measurement radio signals. to measure a characteristic of each received measurement radio signal indicative of the suitability of the potential relay node associated with that measurement radio signal for acting as a relay node for relaying a further radio signal between the terminal device and infrastructure equipment of the wireless telecommunications system, and based on each received measurement radio signal and its measured characteristic, to determine a suitable one of the plurality of potential relay nodes for acting as a relay node for relaying the further radio signal between the terminal device and the infrastructure equipment, and to control one of the transmitter to transmit the further radio signal to the infrastructure equipment via the determined relay node and the receiver to receive the further radio signal from the infrastructure equipment via the determined relay node; wherein the common predetermined radio frequency band is a predetermined narrowband with a bandwidth defined by that of a predetermined number of physical resource blocks, PRBs, adjacent to each other in the frequency domain, the predetermined narrowband being only for the transmission of the measurement radio signals.