Telecommunications apparatus and methods to transmit wake-up signal comprising synchronisation signalling

A network access node for use in a wireless telecommunications system comprising the network access node and a terminal device, wherein the network access node comprises controller circuitry and transceiver circuitry configured to operate together such that the network access node is operable to:

• establish that a downlink message for the terminal device to decode is going to be transmitted by the network access node;
• select an amount of synchronization signaling from among a plurality of predetermined amounts of synchronization signaling for use by the terminal device to achieve radio synchronization with the network access node;
• and
• transmit wake-up signaling to the terminal device in advance of transmitting the downlink message to provide the terminal device with an indication the downlink message for the terminal device to decode is going to be transmitted,
• wherein the wake-up signaling comprises the amount of synchronization signaling for use by the terminal device to achieve radio synchronization with the network access node,
• wherein the selected amount of synchronization signaling from among the plurality of predetermined amounts of synchronization signaling is selected based on an amount of time elapsed since the terminal device previously achieved radio synchronization with the network access node.

A terminal device for use in a wireless telecommunications system comprising the terminal device and a network access node, wherein the terminal device comprises controller circuitry and transceiver circuitry configured to operate together such that the terminal device is operable to:

• determine an amount of synchronization to be transmitted with wake-up signaling transmitted to the terminal device based on a plurality of discontinuous reception mode (DRX) thresholds received from the network access node prior to receipt of the wake-up signaling and an amount of time elapsed since the terminal device previously achieved radio synchronization with the network access node, the plurality of discontinuous reception mode (DRX) thresholds being associated with respective different amounts of synchronization signaling, and
• receive the wake-up signaling transmitted to the terminal device by the network access node to provide the terminal device with an indication a downlink message for the terminal device to decode is going to be transmitted, the wake-up signaling comprising an indication of the amount of synchronization signaling for use by the terminal device to achieve radio synchronization with the network access node,
• wherein the amount of synchronization signaling depends on the amount of time elapsed since the terminal device previously achieved radio synchronization with the network access node.