Question: In a 5G network, when a UE uses Type 1 channel access procedures for UL transmissions with a specific channel access priority class, and HARQ-ACK feedback is not available after the last update of the contention window (CW), what determines the next step in adjusting CW?
Option 1: The UE immediately increases CW for every priority class to the next higher allowed value.
Option 2: The UE checks if the upcoming transmission would be within a specific duration (Δ) from the end of the reference duration corresponding to the earliest UL channel occupancy after the last CW update.
Option 3: The UE maintains the current CW value for every priority class without change, proceeding directly to step 2.
Option 4: The UE reverts to using the default CW value defined for the channel access priority class.
Explanation: According to the procedure outlined for adjusting the contention window when HARQ-ACK feedback is not available, if the UE's transmission after the procedure does not include a retransmission or would be transmitted within a duration (Δ) from the end of the reference duration corresponding to the earliest UL channel occupancy after the last update of CW, the UE proceeds with maintaining CW. Otherwise, it increases CW. Thus, the determinant for the next step is whether the upcoming transmission falls within a specific time frame (Δ) from the end of the reference duration.