Sidelink LCP Using Shared COT Information for Faster Channel Access
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Solution Overview
Problem
Existing wireless communication systems in NR-U and SL-U scenarios face inefficiencies due to varying LBT procedures, particularly in channel occupancy time (COT) sharing, which affects transmission efficiency and resource allocation in sidelink communications.
Innovation Solution
The implementation of a user equipment (UE) with a MAC layer configured to determine and utilize shared COT information for sidelink grants, selecting destinations and logical channels based on usable COT information, and performing appropriate LBT procedures to enhance logical channel prioritization (LCP).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LBT type 1 procedure is performed before transmission, then channel access reliability is improved, but transmission efficiency deteriorates due to longer sensing period
Solution Approach 1:
The system dynamically selects between LBT type 1 and LBT type 2 procedures based on whether COT sharing is applicable. When COT sharing conditions are met, LBT type 2 is used for faster access; otherwise, LBT type 1 ensures reliable access. This dynamic adaptation resolves the contradiction by adjusting the LBT procedure type according to channel conditions and COT availability.
Solution Approach 2:
The sensing period parameter is changed based on the LBT procedure type selected. LBT type 2 uses a shortened sensing period (e.g., 25% of LBT type 1 duration) when operating within a shared COT, while LBT type 1 uses the full sensing period for standalone channel access. This parameter adjustment directly addresses the efficiency-reliability trade-off.
2Productivity
If COT sharing is implemented for SL-U, then transmission efficiency is improved through LBT type 2 procedure, but system complexity increases due to COT management
Solution Approach 1:
COT sharing information is determined and prepared in advance during the MAC layer processing, before the actual transmission occurs. The UE identifies usable shared COT information and associates it with the SL grant during the LCP procedure, allowing efficient LBT type 2 execution without real-time decision complexity.
Solution Approach 2:
The MAC layer acts as an intermediary that manages COT information between the physical layer and the transmission process. It receives COT information from the physical layer, determines usability, and guides the LCP procedure accordingly, simplifying the overall COT management complexity.
3Productivity
If shared COT information is determined during LCP procedure, then resource allocation efficiency is improved, but processing time increases
Solution Approach 1:
The MAC layer determines shared COT information and associates it with the SL grant during the LCP procedure in advance, before MAC PDU assembly and transmission. This preliminary determination ensures that the most efficient LBT procedure and resource allocation are selected upfront, avoiding delays during actual transmission.
Data Source
AI summary
The present application relates to methods and apparatuses for logical channel prioritization (LCP) enhancement with shared channel occupancy time (COT) information. One embodiment of the present disclosure provides a user equipment (UE), which includes: a physical layer; a medium access control (MAC) layer; a transceiver; and a processor coupled with the transceiver, wherein the MAC layer is configured to: determine shared COT information for a sidelink (SL) grant; and select a destination and a logic channel (LCH).