COMMUNICATIONS DEVICE, INFRASTRUCTURE EQUIPMENT, COMMUNICATIONS SYSTEM AND METHODS FOR DOWNLINK DATA TRANSMISSION AND ACKNOWLEDGEMENT

摘要

An infrastructure equipment forms part of a radio access network of a wireless communications network and comprises a transmitter configured to transmit signals to one or more communications devices via a wireless access interface, a receiver configured to receive signals from the one or more communications devices via the wireless access interface, an inter-connecting interface for communicating with one or more other infrastructure equipment of the radio access network of the wireless communications network, and a controller. The controller is configured with the transmitter to transmit a radio network identifier to a communications device, such as a paging identifier, or a radio network temporary identifier, RNTI, which is allocated by the infrastructure equipment for identifying the communications device when allocating communications resources of the wireless access interface for transmitting downlink data to the communications device. After the communications device has entered an inactive connected state, in which the communications device monitors for signals transmitted from the infrastructure equipment, the controller is configured with the transmitter to transmit control signals including the radio network identifier for allocating communications resources of the wireless access interface for the communications device to receive downlink data, to determine whether the communications device is still within a radio coverage area for transmitting signals to and receiving signals from the infrastructure equipment, and if the communications device has left the coverage area, to transmit an indication to the one or more other infrastructure equipment forming part of the radio access network via the inter-connecting interface to trigger a process for transmitting downlink data to the communications device from the one or more other infrastructure equipment. This is for example based on the infrastructure equipment providing, and the communications device using, one of an indication of an acknowledgement preamble, or an indication of a negative acknowledgement preamble, to indicate reception or not of the downlink data transmission.