Unlicensed Band COT Sharing for Efficient Sidelink Access
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Solution Overview
Problem
The challenge in wireless communication systems is to improve channel access efficiency in unlicensed band communication, particularly in sidelink communication, where existing methods do not effectively manage channel occupancy times (COT) for efficient data transmission.
Innovation Solution
A method where a first terminal receives sharing information of a COT initiated by a second terminal and determines if sidelink (SL) transmission is possible within that COT, allowing SL transmission to occur within the shared COT based on type 1 and type 2 LBT operations, and supports unicast, groupcast, and broadcast SL transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a terminal performs independent channel access in unlicensed band, then channel access flexibility is improved, but channel access efficiency deteriorates due to repeated LBT operations and fragmented transmissions
Solution Approach 1:
The patent merges multiple independent channel access operations into a single coordinated transmission opportunity. The first terminal initiates a COT and shares it with the second terminal, allowing both terminals to transmit within the same COT without performing separate LBT operations, thus improving efficiency while maintaining flexibility.
Solution Approach 2:
The first terminal performs preliminary channel sensing and LBT operation to acquire the channel, then shares the acquired COT with the second terminal. This preliminary action eliminates the need for the second terminal to perform redundant LBT operations, improving overall channel access efficiency.
2Reliability
If a terminal performs type 1 LBT operation to initiate COT, then channel access reliability is improved, but transmission time duration increases due to variable sensing period
Solution Approach 1:
The patent extracts the time-consuming LBT operation from the second terminal's transmission process. The second terminal performs a simplified type 2 LBT operation with fixed sensing period, taking out the variable and time-consuming aspects of channel access while maintaining reliability through the first terminal's preliminary COT initiation.
3Adaptability or versatility
If multiple terminals perform independent SL transmissions, then communication versatility is improved, but channel resource utilization deteriorates due to fragmented COTs and repeated LBT operations
Solution Approach 1:
The patent creates a universal COT framework that can accommodate multiple different types of SL transmissions (unicast, groupcast, broadcast) from multiple terminals within a single shared COT. This multi-functional approach allows diverse communication scenarios while improving channel resource utilization by eliminating fragmented COTs.
Data Source
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AI summary
A method and apparatus for channel access in unlicensed band communication are disclosed. The method for a first terminal comprises the steps of: receiving, from a second terminal, shared information of a COT initiated by the second terminal; on the basis of the shared information, determining whether or not an SL transmission by the first terminal may be performed in the COT; and if the SL transmission may be performed in the COT, performing the SL transmission in the COT shared by the second terminal.