Sidelink COT Sharing for Reliable Channel Access in Unlicensed Bands
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Solution Overview
Problem
The increasing demand for mobile broadband communication and the need for enhanced reliability and low latency in wireless communication systems, particularly in sidelink communication between devices, has not been adequately addressed by existing Radio Access Technologies (RATs, especially in unlicensed bands, leading to inefficiencies and overhead in base station operations.
Innovation Solution
A method and apparatus for performing sidelink communication that involves receiving sidelink control information (SCI) including channel occupancy time (COT) sharing information and performing a second type channel access within a COT duration based on this information, with defined processing times for decoding the COT sharing information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing Radio Access Technologies are used for sidelink communication in unlicensed bands, then base station overhead is reduced, but channel access efficiency and latency performance are insufficient
Solution Approach 1:
The transmitting UE performs channel sensing and acquires COT in advance, then shares this pre-acquired channel access opportunity with the receiving UE. This preliminary action allows the receiving UE to transmit without performing its own lengthy channel access procedure, thereby improving channel access efficiency and reducing latency.
Solution Approach 2:
The transmitting UE acts as an intermediary by acquiring COT through its own sensing procedure and then sharing this channel access right with the receiving UE. This intermediary mechanism enables the receiving UE to benefit from the transmitting UE's channel access effort, resolving the contradiction between efficiency and latency.
2Reliability
If channel sensing is performed before each transmission in unlicensed band, then channel access reliability is improved, but transmission latency increases
Solution Approach 1:
The transmitting UE performs channel sensing and acquires COT in advance before the actual data transmission. This preliminary channel access acquisition ensures reliable channel ownership while allowing subsequent transmissions to occur without repeating the sensing process, thus reducing latency while maintaining reliability.
Solution Approach 2:
Once the transmitting UE acquires COT, it maintains continuous channel access rights and shares them with the receiving UE. This continuity eliminates the need for the receiving UE to perform separate channel sensing, ensuring reliable communication while minimizing the time lost to repeated sensing operations.
3Speed
If COT sharing information is transmitted with insufficient processing time, then channel access speed is improved, but decoding reliability deteriorates
Solution Approach 1:
The receiving UE is notified in advance about the upcoming COT sharing and the time required for decoding. This preliminary notification allows the UE to prepare its decoding resources and processes ahead of time, ensuring that sufficient processing time is allocated while maintaining fast channel access speed.
Solution Approach 2:
The SCI includes information about the processing time required for decoding COT sharing information. This feedback mechanism allows the receiving UE to adjust its decoding timeline appropriately, ensuring that decoding reliability is maintained while the channel access proceeds at optimal speed.
Data Source
AI summary
Provided are a method by which a first device performs wireless communication and an apparatus supporting same. The method may comprise the steps of: receiving, in a slot, sidelink control information (SCI) including channel occupancy time (COT) sharing information from a second device; and performing second type channel access within a COT duration acquired on the basis of the COT sharing information.