Ad Hoc Network Timing Synchronization via Periodic Signal Exchange

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Solution Overview

Problem

In ad hoc peer-to-peer wireless communication networks, timing discrepancies between nodes can cause synchronization issues, affecting communication functions such as peer discovery and data transfer, as existing methods struggle to efficiently adjust and maintain synchronized timing across dynamically changing networks.

Innovation Solution

Each node in the network receives a timing reference signal and transmits a wideband signal during a dedicated time interval, while listening during the remaining time, adjusting its timing based on received signals from other nodes to synchronize with the network timing, using methods like averaging or dead zone considerations to mitigate timing offsets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If nodes continuously transmit and receive timing signals to maintain synchronization, then timing synchronization accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvetiming synchronization accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic timing synchronization by dividing time into intervals where nodes alternately transmit and receive timing signals. Instead of continuous operation, nodes perform synchronization at specific periodic intervals, reducing energy consumption while maintaining timing accuracy through regular updates.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuous timing synchronization coverage by ensuring that while individual nodes sleep during certain intervals, the network as a whole continuously has nodes transmitting timing signals. This接力 (relay) approach ensures uninterrupted synchronization information availability without requiring all nodes to be active simultaneously.

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If nodes adjust timing based on all received signals, then synchronization robustness is improved, but processing complexity increases

Engineering Contradiction:
Improvesynchronization robustnessVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by having nodes selectively process timing signals based on their local conditions and requirements. Instead of uniformly processing all received signals, nodes adjust their processing behavior according to their specific network position, signal quality, and synchronization needs, reducing overall processing complexity while maintaining robustness.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes processing parameters dynamically based on network conditions. Nodes adjust timing adjustment parameters, signal selection criteria, and processing intensity according to observed timing offsets, signal strength, and network state, optimizing the balance between synchronization robustness and processing complexity.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If nodes transmit timing signals frequently, then timing offset correction is improved, but network interference increases

Engineering Contradiction:
Improvetiming offset correctionVSAvoidnetwork interference
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent segments the timing signal transmission process by dividing the network into transmission intervals and reception intervals. Nodes transmit timing signals during designated time slots and remain silent during reception slots, segmenting the potentially interfering continuous transmission into discrete, organized pulses that reduce overall network interference while maintaining correction effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses periodic transmission intervals to limit the frequency of timing signal transmissions. By transmitting at controlled periodic intervals rather than continuously or too frequently, nodes achieve adequate timing offset correction while reducing network interference through spaced-out transmission events.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2165441B1Synchronization of a peer-to-peer communication network
Publication Date: 2016.08.17 QUALCOMM INC
  • EP2165441B1 patent drawingFigure 1
  • EP2165441B1 patent drawingFigure 2~3
  • EP2165441B1 patent drawingFigure 4

AI summary

In an ad hoc peer-to-peer communications network, timing synchronization is facilitated between two or more nodes. A node can establish an original symbol timing and receive a first timing synchronization symbol from a peer node. A timing adjustment can be calculated based in part on the first timing synchronization symbol. An adjusted symbol timing can be established by adjusting the first symbol timing by the calculated timing adjustment amount. The adjusted symbol timing can be conveyed to one or more peer nodes, in order to facilitate timing synchronization among the nodes.