Coordinated Handover for Remote and Relay UEs

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Solution Overview

Problem

In the LTE system, the handover process between evolved remote UE and evolved relay UE results in high signaling overheads and high power consumption due to the need for multiple path switching processes, which complicates service continuity and data security when using an indirect communication mode.

Innovation Solution

A handover method that involves the evolved remote UE and evolved relay UE being handed over together, with the first UE receiving radio resource reconfiguration messages to manage the handover process efficiently, reducing the number of path switching processes and optimizing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If evolved remote UE and evolved relay UE perform inter-cell handover separately with multiple path switching processes, then handover flexibility is improved, but signaling overheads increase and power consumption increases

Engineering Contradiction:
Improvehandover flexibilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent combines the handover processes of evolved remote UE and evolved relay UE into a single coordinated operation. The source base station performs inter-cell handover for both UEs simultaneously, merging multiple path switching processes into one unified procedure, thereby reducing signaling overheads and power consumption while maintaining handover flexibility

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If evolved remote UE and evolved relay UE perform inter-cell handover separately with multiple path switching processes, then handover flexibility is improved, but signaling overheads increase

Engineering Contradiction:
Improvehandover flexibilityVSAvoidsignaling overheads
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent merges the handover signaling for evolved remote UE and evolved relay UE into a single coordinated procedure. The source base station sends unified handover commands and receives unified handover confirmations, combining multiple separate signaling exchanges into one, thereby reducing signaling overheads while preserving handover flexibility

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If relay UE forwards data through IP layer (layer 3), then routing flexibility is improved, but data security deteriorates

Engineering Contradiction:
Improverouting flexibilityVSAvoiddata security
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an evolved relay UE as an intermediary that forwards data at layer 2 instead of layer 3. This intermediary operates between the remote UE and source base station, providing secure layer 2 forwarding while maintaining routing flexibility through coordinated handover management with the target base station

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3979701B1Handover method, terminal device, computer readable storage medium and computer program product
Publication Date: 2024.11.27 HUAWEI TECH CO LTD
  • EP3979701B1 patent drawingFigure 1
  • EP3979701B1 patent drawingFigure 2
  • EP3979701B1 patent drawingFigure 3a-1

AI summary

Embodiments of the present invention relate to a handover method and apparatus. The method includes: receiving, by first UE, a first radio resource reconfiguration message and M second radio resource reconfiguration messages, where the first radio resource reconfiguration message and the M second radio resource reconfiguration messages are sent by a first network device, the first radio resource reconfiguration message includes a first handover command, the first handover command is used to instruct to hand over the first UE from the first network device to a second network device, the second radio resource reconfiguration message includes a second handover command, the second handover command is used to instruct to hand over second UE from the first network device to a third network device, M is a quantity of second UEs in a radio resource control RRC connected mode that are connected to the first UE, and the second network device is the same as or different from the third network device; and handing over, by the first UE, from the first network device to the second network device according to the first handover command. In this way, signaling overheads and power consumption are reduced.