Decentralized Timing Source Selection for D2D Synchronization

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Solution Overview

Problem

Densely populated device-to-device (D2D) communication systems face challenges with resource scaling and uncontrolled interference in synchronization channel transmissions, as all devices attempt to transmit in the same synchronization channel, leading to inefficiencies and interference in timing information broadcasts.

Innovation Solution

A method and system for enabling decentralized timing source selection and deselection in D2D synchronization, where communications devices can switch between timing source (TS) and non-TS modes based on utility metric values, with TS mode devices transmitting timing information blocks (TIBs) and non-TS mode devices not transmitting, to manage resource usage and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all devices transmit in the synchronization channel, then timing information is available to all devices, but resource scaling becomes problematic and interference increases

Engineering Contradiction:
Improvetiming information availabilityVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the synchronization channel transmissions by dividing devices into timing source (TS) mode devices that transmit TIBs and non-TS mode devices that do not transmit. This segmentation reduces the number of simultaneous transmitters, thereby reducing interference while maintaining timing information availability through the distributed TS devices.

Inventive Principle:
Principle #1Segmentation

2Reliability

If all devices transmit in the synchronization channel, then timing information is available to all devices, but resource usage becomes inefficient

Engineering Contradiction:
Improvetiming information availabilityVSAvoidresource usage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the synchronization channel transmissions by dividing devices into timing source (TS) mode devices that transmit TIBs and non-TS mode devices that do not transmit. This segmentation reduces the number of simultaneous transmitters, thereby reducing interference while maintaining timing information availability through the distributed TS devices.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If devices dynamically switch between TS and non-TS modes, then resource scalability improves and interference reduces, but device complexity increases

Engineering Contradiction:
ImproveinterferenceVSAvoidmode switching logic
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements self-service through autonomous mode selection where each device independently evaluates its own conditions (such as received signal quality, battery status, or network role) and automatically switches between TS and non-TS modes based on predefined criteria. This eliminates the need for complex centralized coordination while still achieving dynamic resource management and interference reduction.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3095285B1Method and apparatus for timing source selection and deselection distributed device to device synchronization
Publication Date: 2019.06.19 QUALCOMM INC
  • EP3095285B1 patent drawingFigure 1
  • EP3095285B1 patent drawingFigure 2
  • EP3095285B1 patent drawingFigure 3

AI summary

A method, an apparatus, and a computer program product for wireless communication are provided in connection with enabling timing source selection and deselection in a decentralized manner for distributed D2D synchronization in densely populated communications systems. In an example, a communications device, functioning in a non-timing source (TS) mode, is equipped to receive a request for timing information during a synchronization channel. The communications device may further be equipped to determine whether to switch to a TS mode based on a selection utility metric value. In another example, a communications device, functioning in a TS mode, is equipped to transmit a TIB during a synchronization channel, and determine whether to switch to a non-TS mode based on a deselection utility metric value. In the TS mode, the UE is configured to transmit a TIB, while in the non-TS mode the UE is configured not to transmit the TIB.