Wireless telecommunications system including a first terminal device and a second terminal device wherein the second terminal achieves synchronisation for receiving data from the first terminal using synchronisation signalling transmitted by the first terminal or another network entity

A terminal device for use in a wireless telecommunications system, the terminal device comprising:

• integrated circuitry that includes a controller and a transceiver configured to operate together such that the terminal device is configured to transmit data to a second terminal device in a synchronised device-to-device manner,
• wherein the second terminal device is configured to achieve synchronisation for receiving data from the terminal device using synchronisation signalling transmitted by the terminal device or synchronisation signalling transmitted by another network entity operating in the wireless telecommunications system,
• wherein the terminal device is configured to selectively transmit synchronisation signalling with a predefined characteristic to indicate the synchronisation signalling transmitted by the terminal device is high priority synchronisation signalling and the second terminal device seeks to achieve synchronisation with the terminal device using the high priority synchronisation signalling rather than synchronisation signalling transmitted by the other network entity.

A terminal device for use in a wireless telecommunications system, the terminal device comprising:

• a controller and a transceiver, wherein the terminal device is configured to receive data from a second terminal device in a synchronised device-to device manner, and wherein the terminal device is configured to selectively achieve synchronisation for receiving data from the second terminal device using synchronisation signalling received from the second terminal device or synchronisation signalling received from another network entity operating in the wireless telecommunications system,
• wherein the terminal device is configured to preferentially seek to achieve synchronisation using synchronisation signalling received from the other network entity over synchronisation signalling received from the second terminal device, unless the terminal device detects synchronisation signalling received from the second terminal device is associated with a predefined characteristic which indicates the synchronisation signalling received from the terminal device is high priority synchronisation signalling, in which case the terminal device is configured to seek to achieve synchronisation using the high priority synchronisation signalling received from the second terminal device rather than synchronisation signalling received from the other network entity.