V2X Interface Switching for Synchronized Sidelink-to-Cellular Handover

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Solution Overview

Problem

The independent interface reselection or switch decisions in vehicle-to-everything (V2X) communication between UEs can lead to prolonged interruption times due to asynchronous switching between sidelink (SL) and Uu interfaces, especially during transitions from SL to Uu, lacking synchronization among involved vehicles.

Innovation Solution

Proactive switching mechanism where terminal devices send indications to switch from device-to-device connections to network-routed connections, allowing parallel setup of Uu connections by both devices, reducing latency and service interruption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent interface reselection decisions are made by each UE, then the system allows autonomous adaptation to interface conditions, but the interruption time is prolonged due to asynchronous switching

Engineering Contradiction:
Improveautonomous adaptation to interface conditionsVSAvoidinterruption time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the first UE send a switching indication message to the second UE before actually switching from SL to Uu interface. This advance notification allows the second UE to prepare for the switch in advance, ensuring synchronized switching and avoiding service interruption. The indication message includes necessary information for the second UE to initiate Uu connection setup proactively.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If SL connection is used for V2X communication, then direct device-to-device communication is achieved, but congestion of SL resources or unfulfilled QoS may occur

Engineering Contradiction:
Improvedirect device-to-device communication efficiencyVSAvoidQoS fulfillment
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamics by enabling dynamic switching between SL and Uu interfaces based on real-time conditions. The system monitors SL resource congestion and QoS fulfillment status, and automatically triggers interface reselection from SL to Uu when necessary. This dynamic adaptation ensures both direct communication efficiency when SL is available and reliable QoS when SL becomes congested.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If one UE switches from SL to Uu while the other UE continues using SL, then interface flexibility is maintained, but service interruption is prolonged due to lack of synchronization

Engineering Contradiction:
Improveinterface switching flexibilityVSAvoidservice interruption time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies feedback by having the first UE send a switching indication message to the second UE before switching interfaces. This feedback mechanism ensures that both UEs are aware of the upcoming switch and can coordinate their actions accordingly. The second UE receives the indication and initiates Uu connection setup in advance, ensuring synchronized switching and minimizing service interruption.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3994917B1Proactive switching of v2x communication from sidelink connection to cellular connection
Publication Date: 2026.01.28 NOKIA TECHNOLOGIES OY
  • EP3994917B1 patent drawingFigure 1
  • EP3994917B1 patent drawingFigure 2~3
  • EP3994917B1 patent drawingFigure 4

AI summary

Embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of a proactive switch of vehicle-to-everything communication from a device-to-device connection to a connection routed by one or more network devices. In example embodiments, a first terminal device receives, from a second terminal device via a device-to-device connection, an indication of a decision to switch the device-to-device connection to a connection routed by at least one network device for communication with the second terminal device. Based on the received indication from the second terminal device, the first terminal device then determines proactive switching from the device-to-device connection to the routed connection to be performed. The first terminal device then sends a request to a first network device of the at least one network device to set up the routed connection, the request indicating a cause for the determined proactive switching.