Methods, communications devices and infrastructure equipment

A method of operating a communications device to communicate using a wireless communications network, the method comprising

• determining that the communications device can transmit data via one or more communications resources of an unlicensed channel of a wireless access interface, the communications resources of the unlicensed channel being shared in time with at least one of an infrastructure equipment of a wireless communications network and one or more other communications devices which can also transmit in the communications resources of the unlicensed channel, the transmission of the data by the communications device on the unlicensed channel being arranged in time according to a fixed frame period including a channel occupancy time for transmitting the data and an idle period, and the determining that the communications device can transmit the data on the communications resources of the unlicensed channel comprises
• detecting that one of the infrastructure equipment and one of the one or more other communications devices, which has transmitted signals on the unlicensed channel in a channel occupancy time of a fixed frame period of the infrastructure equipment or the one other communications device has released one or more portions of the channel occupancy time of the fixed frame period which are unused by the infrastructure equipment or the one other communications device, the infrastructure equipment or the one other communications device being a release device, and the communications device being a recipient device, and the method includes
• transmitting, by the communications device as the recipient device, at least part of the data in one or more of the released portions of the unlicensed channel from the channel occupancy time of the fixed frame period of the release device.

A communications device comprising

• transmitter circuitry configured to transmit signals via communications resources of an unlicensed channel of a wireless access interface, the communications resources of the unlicensed channel being shared in time with at least one of an infrastructure equipment of a wireless communications network and one or more other communications devices which can also transmit in the communications resources of the unlicensed channel at different times,
• receiver circuitry configured to receive signals transmitted via the communications resources of the unlicensed channel, and
• controller circuitry configured to control the transmitter circuitry and the receiver circuitry, the controller circuitry being configured with the receiver circuitry
• to determine that the transmitter circuitry can transmit data via one or more of the communications resources of the unlicensed channel according to a fixed frame period, including a channel occupancy time for transmitting the data and an idle period, by detecting that none of the infrastructure equipment and the one or more other communications devices are transmitting according to a clear channel assessment, CCA, phase associated with a channel occupancy time of a fixed frame period, and to control the transmitter circuitry to transmit at least part of the data in one or more of the communications resources of the channel occupancy time of the fixed frame period in the unlicensed channel, wherein the controller circuitry is configured
• to determine that one or more portions of the channel occupancy time of the fixed frame period are unused by the communications device, the time for transmitting at least part of the data in the channel occupancy time being less than a temporal length of the channel occupancy time, and
• to release the one or more portions of the channel occupancy time unused by the communications device as a release device, the one or more portions being released to at least one of the infrastructure equipment and the one or more other communications devices as a recipient device.