D2D Communication Handover to Cellular Network

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Solution Overview

Problem

Existing D2D communication systems lack efficient methods for handover from non-network assisted to network-assisted communication, leading to potential disruptions and suboptimal performance when devices transition between different communication modes and resources.

Innovation Solution

A method where a first radio device determines its coverage within a cellular network, connects to it, and sends a coverage message to a second radio device, followed by receiving and initiating a handover to a second frequency resource and communication protocol, enabling seamless transition to network-assisted D2D communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If D2D communication operates in non-network assisted mode using first frequency resource, then communication flexibility and autonomy are improved, but communication reliability and performance deteriorate when transitioning to network-assisted mode

Engineering Contradiction:
Improvecommunication mode flexibilityVSAvoidhandover reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary actions by establishing coverage determination mechanisms and handover preparation procedures before the actual handover occurs. The first radio device determines coverage status in advance, and the network node prepares handover parameters (second frequency resource, second communication protocol) before they are needed, ensuring smooth transition to network-assisted mode.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network node acts as an intermediary that facilitates the transition from non-network assisted to network-assisted D2D communication. It receives coverage determination information from the first radio device, processes handover requests, and provides the second frequency resource and second communication protocol parameters, mediating the complex handover process between autonomous and network-controlled modes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If handover from non-network assisted to network-assisted D2D communication is implemented, then communication performance and robustness are improved, but system complexity and interruption risk increase

Engineering Contradiction:
Improvecommunication robustnessVSAvoidhandover procedure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The handover procedure is segmented into distinct phases: coverage determination phase (first radio device determines if it is within network coverage), information transmission phase (coverage information sent to network node), handover parameter reception phase (network node provides second frequency resource and second communication protocol), and execution phase (actual handover to network-assisted mode). This segmentation makes the complex handover process more manageable and less error-prone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback mechanisms where the first radio device sends coverage determination information to the network node, and the network node responds with handover parameters including the second frequency resource and second communication protocol. This feedback loop ensures that handover decisions are based on actual coverage conditions and that the receiving device has the necessary information to complete the transition smoothly.

Inventive Principle:
Principle #23Feedback

3Productivity

If D2D communication uses first frequency resource without network assistance, then spectrum efficiency is improved, but interference management and resource coordination deteriorate

Engineering Contradiction:
Improvespectrum efficiencyVSAvoidinterference management
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts the operating mode and frequency resources based on network coverage conditions. When in non-network assisted mode, the first radio device uses the first frequency resource autonomously to maintain spectrum efficiency. When coverage is determined and handover to network-assisted mode is executed, the system transitions to using the second frequency resource under network control, dynamically adapting to balance spectrum efficiency with interference management requirements.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2901797B1Method for d2d radiocommunication
Publication Date: 2018.11.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2901797B1 patent drawingFigure 1A~1B
  • EP2901797B1 patent drawingFigure 1C1~1C2
  • EP2901797B1 patent drawingFigure 2~4

AI summary

The present disclosure relates to a method of a first radio device (102) in non- network assisted device-to-device (D2D) communication with a second radio device (103) using a first frequency resource and a first communication protocol. The method comprises determining that the first radio device is within coverage of a cellular network (100). The method also comprises connecting to the cellular network. The method also comprises sending a message to the second radio device, informing said second radio device that the first radio device is within coverage of the cellular network. The method also comprises receiving a message from the cellular network comprising information about a second frequency resource and a second communication protocol. The method also comprises initiating a handover of the D2D communication from the first frequency resource and communication protocol to the second frequency resource and communication protocol.