Sidelink COT Sharing for Coordinated Unlicensed Channel Access
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently sharing channel occupancy time (COT) between sidelink (SL) mode-1 and Uu-unlicensed and SL-unlicensed channels, particularly in unlicensed bands, due to the lack of effective channel access methods.
Innovation Solution
Methods, architectures, and systems are developed for channel access with COT sharing in SL mode-1, incorporating assistance information from both Tx and Rx WTRUs and gNBs to optimize channel access in both Uu-unlicensed and SL-unlicensed environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If channel sensing is performed independently for Uu and SL unlicensed channels, then channel availability can be determined, but channel access efficiency deteriorates due to lack of coordination
Solution Approach 1:
The patent combines independent channel sensing operations for Uu and SL unlicensed channels into a coordinated channel access procedure. The gNB schedules SL transmissions by coordinating with the WTRU's channel sensing results, merging what would otherwise be separate independent access procedures into a unified coordinated approach that improves efficiency while maintaining reliability.
2Productivity
If COT sharing is implemented without coordination information, then resource utilization can be improved, but interference increases due to lack of awareness
Solution Approach 1:
The patent implements feedback mechanisms where the WTRU reports channel sensing results and COT status back to the gNB. This feedback enables the gNB to make informed scheduling decisions that optimize resource utilization while avoiding interference by being aware of the current channel occupation state and coordinating subsequent transmissions accordingly.
Solution Approach 2:
The gNB acts as an intermediary that coordinates between the WTRU's SL transmissions and the network's Uu transmissions in unlicensed bands. By receiving sensing information from the WTRU and providing scheduling decisions, the gNB mediates resource allocation to maximize utilization while minimizing interference between different transmission types.
3Productivity
If SL transmissions are scheduled without COT coordination, then transmission opportunities increase, but channel access reliability deteriorates
Solution Approach 1:
The patent implements preliminary channel sensing and reporting by the WTRU before SL transmissions are scheduled. The WTRU performs channel sensing in advance, reports the results to the gNB, and only then does the gNB schedule transmissions. This preliminary action ensures that subsequent transmission opportunities are based on verified channel availability, maintaining reliability while enabling productive use of the channel.
Data Source
AI summary
Procedures, methods, architectures, apparatuses, systems, devices, and computer program products directed to channel access with channel occupancy time (COT) sharing are described herein. A method implemented in a wireless transmit/receive unit (WTRU) includes transmitting, to a base station, first scheduling information associated with a SL transmission to be transmitted to another WTRU in unlicensed spectrum. The method includes receiving, from the base station, second scheduling information indicating a scheduling of the SL transmission and a shared COT, wherein the shared COT may be shared between any of uplink, downlink and sidelink transmissions. The method includes determining that the SL transmission is scheduled in the shared COT. The method includes transmitting the SL transmission to the other WTRU with no listen before talk (LBT) or with a shorter LBT than a full LBT based on the determining that the SL transmission may be scheduled in the shared channel occupancy time.