PC5 Unicast L2 ID Update for Terminal Privacy Protection

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Solution Overview

Problem

In PC5 unicast connection establishment, the broadcast transmission of the source Layer 2 identifier (L2 ID) exposes the initiating terminal to tracking and recognition risks by other user equipment, compromising privacy.

Innovation Solution

Updating the source L2 ID to a second source L2 ID, which is different from the initial L2 ID used in the sidelink establishment request, ensuring the new ID is used in subsequent communication messages to establish and maintain a secure PC5 unicast link.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the source L2 ID is transmitted in broadcast manner for PC5 unicast connection establishment, then the connection establishment process can be initiated, but the initiating terminal becomes vulnerable to tracking and recognition by other user equipment

Engineering Contradiction:

Improveconnection establishmentVSAvoidtracking and recognition risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by having the initiating terminal generate a new source L2 ID before the connection establishment process completes. This new ID is prepared in advance and then transmitted to the peer terminal through the established unicast connection, allowing the terminal to proactively protect its identity before any tracking can occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements parameter changes by modifying the source L2 ID parameter during the connection process. The initiating terminal changes its source L2 ID from the initial broadcasted ID to a newly generated ID, thereby altering the identifying parameter to prevent tracking while maintaining communication functionality.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If a new source L2 ID is generated and transmitted through unicast communication, then privacy protection is improved, but additional communication steps and message exchanges are required

Engineering Contradiction:

Improveprivacy protectionVSAvoidcommunication process

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The new source L2 ID is generated in advance as a preliminary action, ready for transmission. This preparation phase occurs before the actual privacy protection need arises, allowing the ID to be seamlessly integrated into the ongoing communication without requiring complex real-time generation mechanisms.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The new source L2 ID acts as an intermediary element that bridges the need for privacy protection and the existing communication protocol. By introducing this intermediate identifier, the patent enables privacy protection while maintaining compatibility with the standard PC5 unicast connection establishment process.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4132029B1Identification information update method, terminal and network device

Publication Date: 2026.02.11 VIVO MOBILE COMM CO LTD

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AI summary

Embodiments of the present invention disclose an identifier information updating method, a terminal, and a network device. The method includes: sending a second source L2 ID of a first terminal to a second terminal, where the second source L2 ID is different from a first source L2 ID used in a sidelink establishment request message.