Dynamic Map Relay During Base Station Handover for Level 4 Driving

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Solution Overview

Problem

Existing systems fail to maintain Level 4 automated driving during base station handover due to communication interruptions, leading to loss of dynamic map information and a subsequent reduction in automated driving performance.

Innovation Solution

A dynamic map delivery system that utilizes sidelink communication between vehicles and roadside units to relay dynamic map information during fallback operations, ensuring continuous delivery of dynamic map data through handover by predicting or determining handover timing and using predictive dynamic information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If base station switching by handover is performed under fallback operation, then communication continuity is maintained, but dynamic map information is lost during handover

Engineering Contradiction:

Improvecommunication continuityVSAvoiddynamic map information

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The application server predicts handover timing in advance and performs preliminary actions to ensure continuous dynamic map delivery. The server determines predicted handover timing based on vehicle position and base station information, then prepares to maintain delivery sessions across handover events, preventing information loss before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the application server receives delivery status information from base stations and adjusts delivery strategies accordingly. This feedback loop allows the server to monitor whether dynamic map information is successfully delivered during handover and modify future delivery decisions based on observed performance.

Inventive Principle:

Principle #23Feedback

2Reliability

If redundant sessions are constantly set up to avoid communication quality deterioration, then communication reliability is improved, but system complexity and resource consumption increase

Engineering Contradiction:

Improvecommunication qualityVSAvoidsession management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of constantly setting up redundant sessions, the system applies partial action by establishing redundancy only when predicted handover timing indicates potential delivery failure. The application server selectively creates backup delivery sessions based on predicted communication conditions, avoiding unnecessary session management complexity while maintaining reliability when needed.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system changes operational parameters dynamically based on predicted handover timing and communication conditions. The application server adjusts delivery parameters such as session establishment, data transmission timing, and redundancy levels according to the predicted state of communication channels, optimizing the balance between reliability and complexity.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If dynamic map delivery continues during handover, then information delivery is maintained, but delivery information is lost due to communication interruption

Engineering Contradiction:

Improvedynamic map delivery continuityVSAvoiddelivery information

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The application server performs preliminary determination of predicted handover timing and prepares delivery strategies in advance. By knowing when handover will occur, the server can schedule dynamic map deliveries to avoid interruption points, ensuring continuous information delivery without loss during the handover process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The application server acts as an intermediary that coordinates between the vehicle and base stations during handover. It receives delivery status information from base stations and uses this information to adjust delivery decisions, mediating the communication between different network elements to prevent information loss during the transition.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4310813B1Application server, base station, dynamic map distribution system, control circuit, storage medium, and information distribution method

Publication Date: 2025.08.13 MITSUBISHI ELECTRIC CORP

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AI summary

An application server (10) delivers dynamic map information to a mobile object (30x) that receives the dynamic map information, the dynamic map information being information of a dynamic map that is used for execution of fully automated driving under a specific condition. When the mobile object (30x) executes a handover from a base station (20a) capable of transmitting the dynamic map information in a first area to a base station (20b) capable of transmitting the dynamic map information in a second area, in a case where the mobile object (30x) is in fallback operation in which simultaneous communication with the base stations (20a, 20b) is unavailable, the application server (10) delivers the dynamic map information to the mobile object (30x) via the base station (20a) and a mobile object (30y) capable of receiving the dynamic map information from the base station (20a).