A method of operating network infrastructure equipment in a wireless telecommunications system configured to support communications between the network infrastructure equipment and terminal devices using a primary component carrier operating on radio resources within a first frequency band and a secondary component carrier operating on radio resources within a second frequency band, wherein the second frequency band comprises radio resources which are shared with wireless communication devices that are not part of the wireless telecommunications system, wherein the wireless telecommunications system supports a connected mode of operation in which terminal devices receive user-plane data from the network infrastructure equipment using the primary and secondary component carriers and an idle mode of operation in which terminal devices do not receive user-plane data from the network infrastructure equipment, wherein the method comprises the network infrastructure equipment: communicating user plane-data with a first terminal device operating in the connected mode using the primary and secondary component carriers; configuring a second terminal device to monitor radio channel conditions for radio resources within the second frequency band by making measurements of radio channel conditions for radio resources within the second frequency band, wherein each measurement of radio channel conditions comprises a measurement of a signal strength received by the second terminal device on the radio resources wherein the measurement of a signal strength received by the terminal device is a Received Signal Strength Indicator, RSSI, and to determine if a measurement of a signal strength comprised in each measurement of radio channel conditions meets a trigger criterion, and if so, transmit a measurement report to the network infrastructure equipment to indicate the trigger criterion has been met; receiving a measurement report from the second terminal device indicating the second terminal device has determined a measurement of a signal strength comprised in a measurement of radio channel conditions met the trigger criterion; and modifying the radio resources used for communication of user-plane data with the first terminal device using the secondary component carrier in response thereto. communicating user plane-data with a first terminal device operating in the connected mode using the primary and secondary component carriers; configuring a second terminal device to monitor radio channel conditions for radio resources within the second frequency band by making measurements of radio channel conditions for radio resources within the second frequency band, wherein each measurement of radio channel conditions comprises a measurement of a signal strength received by the second terminal device on the radio resources wherein the measurement of a signal strength received by the terminal device is a Received Signal Strength Indicator, RSSI, and to determine if a measurement of a signal strength comprised in each measurement of radio channel conditions meets a trigger criterion, and if so, transmit a measurement report to the network infrastructure equipment to indicate the trigger criterion has been met; receiving a measurement report from the second terminal device indicating the second terminal device has determined a measurement of a signal strength comprised in a measurement of radio channel conditions met the trigger criterion; and modifying the radio resources used for communication of user-plane data with the first terminal device using the secondary component carrier in response thereto.