Reduced Wireless Handover Command Size

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Solution Overview

Problem

Current handover procedures in wireless communication networks face challenges due to the time required for transmitting large configuration messages, which can lead to failed handovers as the radio channel degrades during the handover process, resulting in call drops.

Innovation Solution

The solution involves transmitting the configuration information in two parts: a first handover command message with initial configuration information during the handover preparation phase when the radio channel is still acceptable, and a second handover command message with additional configuration information received from the target node after the initial message is sent, allowing the UE to access the target node efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the Handover Command message contains a large amount of UE configuration information, then the configuration is complete for target cell access, but the message delivery time increases and the likelihood of successful reception decreases due to degrading radio channel conditions

Engineering Contradiction:
Improvehandover success rateVSAvoidhandover execution time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The Handover Command message is divided into two separate parts: a first Handover Command message containing essential configuration information for immediate target cell access, and a second Handover Command message containing additional configuration information. This segmentation allows the critical handover parameters to be transmitted quickly when radio conditions are still acceptable, while non-critical parameters can be sent later without delaying the handover execution.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the Handover Command message is transmitted with all configuration information, then the UE has complete configuration for target cell access, but the message size increases leading to longer transmission time and higher failure probability

Engineering Contradiction:
Improveconfiguration completenessVSAvoidmessage size
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The configuration information in the Handover Command is segmented into essential parameters (first part) and non-essential parameters (second part). The first part includes critical parameters needed for immediate target cell access such as cell ID, random access parameters, and security parameters. The second part includes additional parameters that can be provided later without preventing handover execution.

Inventive Principle:
Principle #1Segmentation

3Loss of information

If the handover procedure uses a single comprehensive Handover Command message, then all configuration parameters are provided in one message, but the overall handover time increases and call drops occur due to channel degradation

Engineering Contradiction:
Improveconfiguration information deliveryVSAvoidhandover execution duration
Core Design Contradiction:
Loss of informationVSDuration of action of moving object

Solution Approach 1:

The essential configuration information for target cell access is provided in the first Handover Command message before the radio channel condition degrades further. This preliminary provision of critical parameters ensures that the UE can initiate target cell access immediately, while the second message with additional parameters is transmitted after the UE has already connected to the target cell, eliminating the risk of channel degradation affecting the entire configuration delivery.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2997765B1Reduced wireless communication handover command size during handover execution
Publication Date: 2019.07.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2997765B1 patent drawingFigure 1
  • EP2997765B1 patent drawingFigure 2
  • EP2997765B1 patent drawingFigure 3

AI summary

A node and method for communication with a user equipment, UE, are provided. The source node includes at least one processor configured to cause transmission of a first handover command message to the UE. The first handover command message includes first configuration information for handover to a target node. At least one receiver is configured to receive second configuration information from the target node after transmission of the first handover command message to the UE. The at least one processor is further configured to cause transmission of a second handover command message to the UE. The second handover command message includes the second configuration information received from the target node. The first configuration information is configured to be used in combination with the second configuration information to allow the UE to access the target node for handover.