LTE Handover Control Using MDT Speed Prediction

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Solution Overview

Problem

The existing techniques for estimating the moving speed of mobile terminals in LTE networks have low accuracy, leading to a decreased handover success rate due to inaccuracies in predicting the actual speed.

Innovation Solution

A communication system that includes a base station and a mobile management device, which receives a speed prediction value from a trace collection server and transmits it to the base station for handover control, allowing for periodic updates and adjustments in measurement configuration based on the predicted speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If moving speed is estimated from cell movement history, then handover control can be performed based on speed information, but estimation accuracy is low leading to decreased handover success rate

Engineering Contradiction:
Improvehandover success rateVSAvoidmoving speed estimation accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces MDT measurement information as an intermediary to obtain more accurate terminal movement speed. Instead of directly estimating speed from cell movement history, the system uses MDT measurements (which include terminal position, speed, and direction) as a mediator to provide more precise speed information for handover control, thereby resolving the accuracy problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical estimation method (calculating speed from cell movement history) with a measurement-based approach (using MDT measurement information). This substitution transitions from an indirect mechanical inference system to a direct measurement system, significantly improving speed estimation accuracy for handover control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If MDT measurement configuration is updated frequently to improve speed prediction accuracy, then handover success rate improves, but network signaling overhead and device power consumption increase

Engineering Contradiction:
Improvehandover success rateVSAvoiddevice power consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements dynamic adjustment of MDT measurement configuration based on actual network conditions and terminal movement patterns. The measurement configuration is not fixed but adapts to changing conditions, allowing the system to optimize between accuracy and energy consumption by adjusting measurement frequency and parameters according to actual needs.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes measurement parameters (such as measurement interval, measurement type) based on terminal speed and handover conditions. By dynamically adjusting these parameters, the system achieves accurate speed prediction only when necessary, reducing unnecessary measurements and thereby lowering power consumption while maintaining handover success rate.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3358884B1Communication system and control method
Publication Date: 2021.09.08 NEC CORP
  • EP3358884B1 patent drawingFigure 1
  • EP3358884B1 patent drawingFigure 2
  • EP3358884B1 patent drawingFigure 3

AI summary

A success rate of handover is improved. A communication system includes a base station and a mobile management device. The mobile management device includes first reception means for receiving speed information on a mobile terminal based on measurement information by MDT (Minimization of Driving Test), and first transmission means for transmitting a message including the speed information to the base station. The base station includes second reception means for receiving a message including the speed information and control means for performing handover control based on the speed information which is received.