Inter-UE Coordination Message Priority in NR V2X MAC PDU

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Solution Overview

Problem

In wireless communication systems, the ambiguity in priority of inter-UE coordination messages within MAC PDUs leads to difficulties in performing logical channel prioritization, and distinguishing such messages from regular data is challenging, affecting efficient sidelink communication.

Innovation Solution

The method involves generating MAC PDUs with inter-UE coordination information, where the MAC CE for coordination messages has a specific priority lower than sidelink control channel data but higher than sidelink traffic channel data, and includes a source ID and destination ID in sidelink control information for clear resource assignment and recognition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If inter-UE coordination message is included in MAC CE or MAC SDU, then the message can be transmitted within MAC PDU, but the priority of the message becomes ambiguous making LCP procedure impossible

Engineering Contradiction:
ImproveLCP procedure executionVSAvoidpriority information
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent introduces a new parameter - logical channel priority - specifically for inter-UE coordination messages. By assigning a distinct priority value (different from SCCH and STCH data), the message gains clear identification within the MAC PDU structure, enabling the LCP procedure to function properly. This parameter change transforms the ambiguous priority state into a defined priority state.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If UE transmits inter-UE coordination message to another UE, then resource selection coordination is achieved, but the receiving UE cannot distinguish the message from general data

Engineering Contradiction:
Improvemessage recognitionVSAvoidmessage type information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies a metaphorical 'color change' by assigning a unique priority identifier to inter-UE coordination messages. This identifier acts as a distinctive marker that allows the receiving UE to differentiate coordination messages from regular data messages. The priority value serves as an identifying characteristic that enables reliable message recognition without requiring additional message type fields.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP4171151B1Method and device for transmitting/receiving inter-UE coordination message in NR v2x
Publication Date: 2025.01.01 LG ELECTRONICS INC
  • EP4171151B1 patent drawingFigure 1
  • EP4171151B1 patent drawingFigure 2(a)~2(d)
  • EP4171151B1 patent drawingFigure 3

AI summary

A method by which a first device performs wireless communication, and a device for supporting same are provided. The method may comprise the steps of: transmitting, to a second device, through a physical sidelink control channel (PSCCH), first sidelink control information (SCI) for the scheduling of second sidelink control information (SCI) and a physical sidelink shared channel (PSSCH), the first SCI including information related to a frequency resource allocation, information related to a time resource allocation, and information related to the format of the second SCI; and transmitting, to the second device, through the PSSCH, an inter-UE coordination message and the second SCI including a source ID and a destination ID. The inter-UE coordination message can include information related to a preferred resource or information related to a non-preferred resource, and information indicating that the inter-UE coordination message has been transmitted can be included in the first SCI or the second SCI.