SL UE Assistance Patterns for Half-Duplex Sidelink Reliability

Solution Overview

Problem

The half-duplex issue in sidelink communication between user equipments (UEs) results in unreliable unicast and multicast communications due to simultaneous transmission and reception limitations, failing to meet latency requirements in 5G vehicle-to-everything (V2X) operations.

Innovation Solution

UEs exchange SL UE assistance information, including pattern information such as transmission periodicity, time intervals, and resource mappings, to coordinate resource usage and avoid collisions, employing RRC and MAC CE messages for updates and feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If UE uses half-duplex communication on sidelink, then device complexity is reduced, but communication reliability deteriorates due to inability to receive and transmit simultaneously

Engineering Contradiction:

Improvedevice complexityVSAvoidcommunication reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The receiving UE performs preliminary action by transmitting SL UE assistance information (including pattern information about its transmission activities) to the transmitting UE before the actual data transmission. This allows the transmitting UE to advance plan its resource selection, identifying time-domain resources where the receiving UE will be transmitting and thus avoiding selecting those resources, thereby preventing half-duplex conflicts before they occur.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If Tx UE selects same time-domain resource as Rx UE transmission, then resource utilization is improved, but communication reliability deteriorates due to half-duplex conflict

Engineering Contradiction:

Improveresource utilizationVSAvoidcommunication reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The receiving UE provides feedback to the transmitting UE by transmitting SL UE assistance information that includes pattern information about its transmission activities. This feedback enables the transmitting UE to make informed resource selection decisions, avoiding time-domain resources where the receiving UE will be transmitting, thus preventing half-duplex conflicts while still achieving efficient resource utilization by selecting from the remaining available resources.

Inventive Principle:

Principle #23Feedback

3Reliability

If retransmission is performed due to failed reception, then communication reliability is improved, but latency increases failing to meet service requirements

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The receiving UE performs preliminary action by transmitting SL UE assistance information (including pattern information about its transmission activities) to the transmitting UE before the actual data transmission. This allows the transmitting UE to advance plan its resource selection, identifying time-domain resources where the receiving UE will be transmitting and thus avoiding selecting those resources, thereby preventing half-duplex conflicts before they occur.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3905733B1Information transmission method and terminal

Publication Date: 2026.02.04 DATANG MOBILE COMM EQUIP CO LTD

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AI summary

Embodiments of this disclosure provide an information transmission method and user equipment. The method includes: receiving, by first UE, SL UE assistance information transmitted by second UE, wherein the SL UE assistance information includes at least one piece of pattern information; determining, by the first UE according to the SL UE assistance information, a resource occupied by transmission between the first UE and the second UE.