Flexible slot structure for cellular communication in unlicensed spectrum

A wireless device, comprising:

• an antenna;
• a radio operably coupled to the antenna;
• and
• a processor operably coupled to the radio;
• wherein the antenna, radio, and processor are configured to:
• receive a reservation frame from a cellular base station, wherein the reservation frame indicates a length, wherein the reservation frame reserves an unlicensed wireless medium for a transmit opportunity (TXOP) of the indicated length;
• receive scheduling information from the cellular base station indicating one or more transmission slots scheduled for communication between the wireless device and the cellular base station during the TXOP, wherein transmission slot types of the transmission slots are selected from a plurality of transmission slot types including—unidirectional uplink and downlink and bidirectional uplink and downlink transmission slot types;
• and
• perform wireless communication with the cellular base station on the unlicensed wireless medium according to the scheduled transmission slots, wherein said performing wireless communication includes, in response to a determination that the one or more transmission slots includes an uplink transmission slot:
• determine whether the uplink transmission slot is within the TXOP;
• and
• select a type of listen-before-talk procedure, from a plurality of possible types of listen-before-talk procedures, to perform prior to the uplink transmission slot based at least in part on the determination of whether the uplink transmission slot is within the TXOP, wherein a first type of listen-before-talk procedure of the plurality of possible types of listen-before-talk procedures includes a short listen-before-talk procedure performed during a ½ symbol switching gap between uplink and downlink symbols and wherein the plurality of possible types of listen-before-talk procedures further includes a second type of listen-before-talk procedure different from the first type of listen-before-talk procedure.

A method for operating a wireless device, the method comprising:

• at the wireless device:
• receiving a reservation frame from a cellular base station, wherein the reservation frame indicates a length, wherein the reservation frame reserves a wireless medium for a transmit opportunity (TXOP) of the indicated length;
• receiving scheduling information from the cellular base station indicating one or more uplink and/or downlink transmission slots scheduled for communication between the wireless device and the cellular base station during the TXOP, wherein transmission slot types of the uplink and/or downlink transmission slots are selected from a plurality of transmission slot types including—unidirectional uplink and downlink and bidirectional uplink and downlink transmission slot types;
• and
• performing wireless communication with the cellular base station according to the scheduled uplink and/or downlink transmission slots, wherein, when the one or more uplink and/or downlink transmission slots comprises an uplink transmission slot, the method further comprises:
• determining whether the uplink transmission slot is within the TXOP;
• and
• selecting a type of listen-before-talk procedure, from a plurality of possible types of listen-before-talk procedures, to perform prior to the uplink transmission slot, wherein the type of listen-before-talk procedure is selected from the plurality of possible types of listen-before-talk procedures based at least in part on the determination of whether the uplink transmission slot is within the TXOP, wherein a first type of listen-before-talk procedure of the plurality of possible types of listen-before-talk procedures includes a short listen-before-talk procedure performed during a ½ symbol switching gap between uplink and downlink symbols and wherein the plurality of possible types of listen-before-talk procedures further includes a second type of listen-before-talk procedure different from the first type of listen-before-talk procedure.