Communication devices and methods

Second communication device configured to communicate with a third communication device, the second communication device comprising circuitry configured to

• stay awake during a scheduling interval, wherein data exchange between the third communication device and a first communication device is planned during the scheduling interval, the first communication device being a primary user of the scheduling interval and the second communication device being a secondary user of the scheduling interval;
• listen to a release indication indicating that the remaining portion of the scheduling interval is released for use by the second communication device;
• and
• contend for channel access and/or perform data exchange with the third communication device during at least the remaining portion of the scheduling interval if
• i) a release indication is received or
• ii) no data exchange between the first communication device and the third communication device is observed for at least an inactivity interval.

Third communication device configured to communicate with a first and/or second communication device, the third communication device comprising circuitry configured to

• perform data exchange with the first communication device during a first portion of a scheduling interval, wherein data exchange between the third communication device and the first communication device is planned during the scheduling interval, the first communication device being a primary user of the scheduling interval;
• and
• i) receive a first release indication from the first communication device indicating that the first communication device has finished data exchange with the third communication device during the scheduling interval and transmit a second release indication indicating that the remaining portion of the scheduling interval is released for use by a second communication device, the second communication device being a secondary user of the scheduling interval, or
• ii) transmit a first release indication indicating that the third communication device has finished data exchange with the first communication device during the scheduling interval, receive a second release indication from the first communication device indicating that the remaining portion of the scheduling interval is released for use by a second communication device, and repeat the transmission of the second release indication, or
• iii) transmit a second release indication or other information indicating or allowing a second communication device to determine that the remaining portion of the scheduling interval is released for use by a second communication device.

Second communication method of a second communication device configured to communicate with a third communication device, the second communication method comprising

• staying awake during a scheduling interval, wherein data exchange between the third communication device and a first communication device is planned during the scheduling interval, the first communication device being a primary user of the scheduling interval and the second communication device being a secondary user of the scheduling interval;
• listening to a release indication indicating that the remaining portion of the scheduling interval is released for use by the second communication device;
• and
• contending for channel access and/or performing data exchange with the third communication device during at least the remaining portion of the scheduling interval if
• i) a release indication is received or
• ii) no data exchange between the first communication device and the third communication device is observed for at least an inactivity interval.

Third communication method of a third communication device configured to communicate with a first and/or second communication device, the third communication method comprising

• performing data exchange with the first communication device during a first portion of a scheduling interval, wherein data exchange between the third communication device and the first communication device is planned during the scheduling interval, the first communication device being a primary user of the scheduling interval;
• and
• i) receiving a first release indication from the first communication device indicating that the first communication device has finished data exchange with the third communication device during the scheduling interval and transmitting a second release indication indicating that the remaining portion of the scheduling interval is released for use by a second communication device, the second communication device being a secondary user of the scheduling interval, or
• ii) transmitting a first release indication indicating that the third communication device has finished data exchange with the first communication device during the scheduling interval, receiving a second release indication from the first communication device indicating that the remaining portion of the scheduling interval is released for use by a second communication device, and repeating the transmission of the second release indication, or
• iii) transmitting a second release indication or other information indicating or allowing a second communication device to determine that the remaining portion of the scheduling interval is released for use by a second communication device.