Relay Communication for Out-of-Coverage Mobility Registration Updates

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Solution Overview

Problem

Remote User Equipment (UE) may move out of a configured registration area or radio access network-based notification area without sensing the current serving cell, leading to failure in initiating timely mobility registration updates due to loss of coverage.

Innovation Solution

A relay communication method where a first terminal sends information to a second terminal regarding the serving cell or the need for mobility registration updating, enabling the second terminal to determine and initiate necessary updates even when out of coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If remote UE moves out of configured registration area or RNA, then the remote UE loses coverage of serving cell and cannot sense current serving cell information, but the remote UE still needs to initiate mobility registration update or RNA update procedure timely

Engineering Contradiction:

Improvemobility registration update timelinessVSAvoidloss of serving cell coverage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The relay UE acts as an intermediary between the remote UE and the serving cell. When the remote UE moves out of coverage, the relay UE forwards serving cell information (such as RNA configuration, TAC, cell ID) from the network to the remote UE through the relay link, enabling the remote UE to maintain awareness of registration area status without direct coverage

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary actions by configuring the remote UE with registration area information (RNA, TAC, cell ID) in advance through the relay link before the remote UE actually moves out of coverage. This allows the remote UE to proactively determine when it has left the registration area and initiate updates timely

Inventive Principle:

Principle #10Preliminary action

2Reliability

If remote UE cannot acquire current serving cell information, then the remote UE cannot determine whether it has moved out of configured registration area or RNA, but the remote UE needs to maintain network registration compliance

Engineering Contradiction:

Improvenetwork registration complianceVSAvoidserving cell information

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The relay UE serves as an information intermediary, acquiring serving cell information (RNA configuration, TAC, cell ID, frequency) from the network through the Uu interface and forwarding it to the remote UE via the PC5 relay link, thus preventing information loss

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The relay UE performs preliminary information acquisition by obtaining serving cell parameters in advance through network signaling and caches them for forwarding to the remote UE, ensuring the remote UE has the necessary information before actually needing to make registration decisions

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12604292B2Relay communication method and apparatus

Publication Date: 2026.04.14 KONINKLIJKE PHILIPS NV

AI summary

This application discloses a relay communication method and apparatus, and pertains to the field of wireless communication technologies. The relay communication method performed by a first terminal includes: sending first information to a second terminal. The first information is used to indicate information related to a serving cell for the first terminal or used to indicate that mobility registration updating or radio access network-based notification area updating is performed by the second terminal.