Cell Re-establishment Determination in Handover

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Solution Overview

Problem

Current handover processes in cellular radio access networks are inefficient, particularly in advanced networks, due to lack of proactive planning for cell splitting or merging, leading to potential delays and failures in maintaining continuous connectivity during handover.

Innovation Solution

Incorporating admission control information and planned cell replacement details in handover requests, allowing the target eNB to identify and prioritize alternative cells for seamless re-establishment in case of handover failures, thereby reducing the need for re-authentication and minimizing downtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional handover process is used without proactive cell planning, then handover procedure is simple, but connectivity continuity and reliability deteriorate during cell splitting or merging

Engineering Contradiction:
Improveconnectivity continuityVSAvoidhandover process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The target eNB performs preliminary actions by pre-identifying replacement cells and preparing re-establishment information before the actual handover occurs. The handover request acknowledgment message includes pre-planned alternative cell information, allowing the UE to quickly recover connectivity if handover fails, thus improving reliability without significantly increasing operational complexity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If handover request acknowledgment includes detailed admission control and alternative cell information, then re-establishment capability is improved, but message size and processing complexity increase

Engineering Contradiction:
Improvehandover success rateVSAvoidinformation overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential information needed for re-establishment from the complete cell deployment plan. Instead of transmitting all cell information, the handover request acknowledgment message includes only the necessary alternative cell identifiers and re-establishment parameters, reducing information overhead while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If target eNB waits for handover completion before cell splitting or merging, then network deployment flexibility is maintained, but handover delays and failures increase

Engineering Contradiction:
Improvenetwork deployment flexibilityVSAvoidhandover downtime
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The target eNB performs cell splitting or merging operations in advance and includes the planned alternative cell information in the handover request acknowledgment message. This allows the UE to be pre-configured with re-establishment cells, enabling faster recovery if handover fails, thus reducing handover downtime while maintaining network deployment flexibility.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If full re-authentication is performed after handover failure, then security is ensured, but service continuity and user experience deteriorate

Engineering Contradiction:
ImprovesecurityVSAvoidservice interruption time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by pre-establishing re-establishment cell information and authentication parameters in the handover request acknowledgment message. When handover fails, the UE can quickly reconnect to the pre-identified alternative cell using pre-shared authentication data, avoiding full re-authentication and thus maintaining both security and service continuity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3275242B1Determination of a re-establishment cell
Publication Date: 2024.01.17 NOKIA SOLUTIONS & NETWORKS OY
  • EP3275242B1 patent drawingFigure 1~2
  • EP3275242B1 patent drawingFigure 3~4
  • EP3275242B1 patent drawingFigure 5

AI summary

A technique comprising: receiving at a second node one or more handover requests from a first node identifying a communication device and a target cell associated with said second node; determining a new target cell and/or a most preferred re-establishment cell; and sending out to the first node information about the result of said determining.