Telecommunications apparatus and methods for performing measurements of an unlicensed carrier

A terminal device configured to performing measurement event evaluation for measurement reporting in respect of a downlink carrier operating in a wireless telecommunications system, the terminal device comprising

• a controller and a transceiver configured to operate together to:
• determine that measurement event evaluation for the downlink carrier should be undertaken from a start time;
• obtain measurements of a parameter associated with radio channel conditions for frequency resources used by the downlink carrier during an evaluation period beginning at the start time;
• establish extent to which the downlink carrier is being transmitted during the evaluation period;
• and
• evaluate whether to send a measurement report to network infrastructure equipment based on the measurements of the parameter during the evaluation period, a measurement of the parameter after the downlink carrier begins transmitting again after an off-period during which the downlink carrier is not being transmitted, and the extent to which the downlink carrier is being transmitted during the evaluation period, and a trigger criterion;
• and
• send the measurement report when the trigger criterion is met and only on condition that the trigger criterion is met, otherwise wait for another start time and never send the measurement report.

Circuitry for a terminal device configured to performing measurement event evaluation for measurement reporting in respect of a downlink carrier operating in a wireless telecommunications system, the circuitry comprising

• a controller and a transceiver configured to operate together to:
• determine that measurement event evaluation for the downlink carrier should be undertaken from a start time;
• obtain measurements of a parameter associated with radio channel conditions for frequency resources used by the downlink carrier during an evaluation period beginning at the start time;
• establish the extent to which the downlink carrier is being transmitted during the evaluation period;
• and
• evaluate whether to send a measurement report to network infrastructure equipment based on the measurements of the parameter during the evaluation period, a measurement of the parameter after the downlink carrier begins transmitting again after an off-period during which the downlink carrier is not being transmitted, the extent to which the downlink carrier is being transmitted during the evaluation period, and a trigger criterion;
• and
• send the measurement report when the trigger criterion is met and only on condition that the trigger criterion is met, otherwise wait for another start time and never send the measurement report.