Autonomous Handover Configuration for High-Speed Train Connectivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless communication systems face challenges in handover procedures for high-speed user equipment (UE) on trains, particularly due to Doppler shifts and increased latency, which affect system and UE throughput, and existing solutions do not adequately account for high-speed train scenarios.

Innovation Solution

A method where a network node provides UE with handover configuration data and context information to autonomously decide on handovers, pre-configuring target cells and conditions based on mobility profiles, including speed and Doppler frequency thresholds, allowing for proactive handover execution before losing source cell coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conventional handover procedures are used in high-speed scenarios, then the system can maintain basic connectivity, but handover latency increases and throughput decreases due to Doppler shifts and delayed cell detection

Engineering Contradiction:
Improvehandover latencyVSAvoidsystem throughput
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The network node pre-configures the UE with handover configuration data including target cell information and event triggering conditions before the handover is needed. This allows the UE to autonomously execute handover when conditions are met, eliminating the delay of real-time measurement reporting and network decision-making, thus reducing handover latency while maintaining throughput

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the UE waits for network commands to perform handover, then handover decisions can be centrally controlled, but the UE may lose source cell coverage before receiving the handover command at high speeds

Engineering Contradiction:
Improvehandover success rateVSAvoidUE movement speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The network provides the UE with pre-configured handover information including target cell identifiers and execution conditions. The UE autonomously determines when to execute handover based on real-time measurements against these pre-set conditions, enabling rapid response to changing radio conditions at high speeds while maintaining network-controlled handover reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The UE is empowered to autonomously execute handover decisions based on pre-configured conditions without requiring real-time network commands. The UE independently monitors radio conditions, compares them against configured thresholds, and triggers handover when conditions are met, enabling the UE to serve itself in high-speed scenarios where network response time is insufficient

Inventive Principle:
Principle #25Self-service

3Loss of time

If the network pre-configures target cells for all possible movements, then handover can be executed quickly, but the complexity of managing handover configurations increases

Engineering Contradiction:
Improvehandover execution timeVSAvoidhandover configuration management
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The network provides handover configuration data for specific target cells based on the UE's current location and movement pattern. Rather than configuring all possible target cells, the network provides configurations for relevant target cells in the UE's anticipated path, reducing configuration complexity while enabling fast autonomous handover execution when needed

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces handover latency and improves throughput by enabling UE to perform handovers in good radio conditions, minimizing interruptions and optimizing handover timing and resource allocation.

Implementation Method 1

high speed movement of the UE may also lead to significant Doppler shifts of the received radio signals

Methodology Applied
Scientific EffectDoppler shift: Doppler Effect

Data Source

PatentEP3251406B1Handover in high speed scenario
Publication Date: 2020.01.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3251406B1 patent drawingFigure 1
  • EP3251406B1 patent drawingFigure 2a~2b
  • EP3251406B1 patent drawingFigure 3~4a

AI summary

A handover procedure is described where a user equipment, UE, (306) is pre-configured by a network node (301) of a source cell (310) with one or more target cells and associated conditions to be fulfilled for the UE to autonomously decide when to execute the handover. The UE may be pre-configured while in good radio conditions, being connected to the source cell, and hence the UE does not risk going out of source cell coverage before being handed over to a target cell.