Contention window determination

A wireless device comprising:

• one or more processors;
• and
• memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
• determine a reference duration for contention window adjustment, wherein the reference duration is from a beginning of a channel occupancy and until an end of a first slot where at least one physical uplink shared channel (PUSCH) is transmitted;
• determine a contention window value based on one or more new data indicators (NDIs) of one or more first transport blocks transmitted during the reference duration;
• perform a listen before talk (LBT) procedure based on the contention window value;
• and
• transmit one or more second transport blocks based on the LBT procedure indicating a clear channel.

A method comprising:

• determining, by a base station, a reference duration for contention window adjustment, wherein the reference duration is from a beginning of a channel occupancy of and until an end of a first slot where at least one physical downlink shared channel (PDSCH) is transmitted;
• determining a contention window value based on a first number of received negative acknowledgement feedbacks and a second number of received positive acknowledgement feedbacks corresponding to a plurality of first transport blocks transmitted during the reference duration;
• performing a listen before talk (LBT) procedure based on the contention window value;
• and
• transmitting one or more second transport blocks based on the LBT procedure indicating a clear channel.