Sidelink Channel Access Priority Coordination

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Solution Overview

Problem

Existing wireless communication systems face challenges in maintaining quality of service (QoS) targets for sidelink communications, particularly in unicast data transmissions, due to higher system loading and channel access delays.

Innovation Solution

The proposed solution involves coordinating channel access between user equipment (UEs) in sidelink communications by agreeing on transmission directions and traffic patterns, where a transmitting UE has higher priority in channel access than a receiving UE. This is achieved through various techniques such as adjusting channel access procedures, energy detection thresholds, contention window sizes, and using layer one signaling to reconfigure channel access priorities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional channel access procedures are used for sidelink unicast communications, then both UEs can attempt channel access equally, but the transmitting UE cannot reliably meet QoS targets due to channel access delays and higher system loading

Engineering Contradiction:

ImproveQoS target meeting probabilityVSAvoidChannel access delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies asymmetry by creating unequal channel access priorities between the two UEs. The transmitting UE is assigned higher priority than the receiving UE for specific resource subsets, allowing it to attempt channel access more frequently and with higher success probability. This asymmetric priority assignment directly addresses the contradiction by ensuring the transmitting UE can reliably meet QoS targets while reducing its channel access delay through preferential treatment in the channel access procedure.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by assigning different channel access priorities to different resource subsets. Instead of uniform treatment across all resources, the transmitting UE receives higher priority specifically for time resource subsets identified as suitable for unicast transmissions. This localized quality differentiation allows the system to optimize QoS for critical transmitting opportunities while maintaining fair access for other resources.

Inventive Principle:

Principle #3Local quality

2Productivity

If the transmitting UE is given higher channel access priority, then data rates increase and QoS targets are met more reliably, but the receiving UE's channel access opportunities are reduced

Engineering Contradiction:

ImproveData rateVSAvoidChannel access opportunity fairness

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent applies segmentation by dividing the total time resources into different subsets: first time resource subsets allocated to the transmitting UE with higher priority, and second time resource subsets where both UEs have equal priority. This segmentation allows the system to optimize productivity for unicast transmissions during first subsets while preserving operational fairness during second subsets, resolving the contradiction between data rate optimization and access opportunity fairness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies dynamics by making channel access priorities dynamic rather than static. The priorities are determined based on identified unicast traffic patterns and can be reconfigured through L1 signaling. This dynamic adjustment allows the system to adapt to changing transmission needs, optimizing data rates when unicast traffic requires prioritization while maintaining fairness when both UEs need equal access opportunities.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If channel access priority is dynamically reconfigured through L1 signaling, then adaptability to changing traffic conditions improves, but signaling overhead and processing complexity increase

Engineering Contradiction:

ImproveChannel access priority reconfiguration capabilityVSAvoidSignaling and processing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling the transmitting UE to autonomously reconfigure channel access priorities for its unicast communications with the receiving UE through L1 signaling. This self-service capability allows the transmitting UE to adapt to changing traffic conditions without requiring network intervention or complex centralized control, thereby improving adaptability while keeping the complexity manageable through distributed decision-making.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12302412B2Coordinated channel access techniques for sidelink communications

Publication Date: 2025.05.13 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described that provide for user equipment (UE) in sidelink communications to agree on transmission directions and a traffic pattern for a sidelink channel, where a transmitting UE has higher priority in channel access than a receiving UE. When establishing a connection via sidelink, two or more UEs may agree on a resource pattern for a set of sidelink resources where a first UE has higher priority than a second UE for a first subset of resources. The first UE may be given higher priority in the first subset of resources through adjustments to a channel access procedure for requesting channel access, adjustments to one or more access thresholds or channel access priority classes, contention window adjustments, or any combinations thereof. Layer one signaling may be used to reconfigure channel access priority and the traffic pattern between UEs.