Mesh Node Beacon Scheduling for Conflict-Free Time Synchronization
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Solution Overview
Problem
Existing time synchronization methods in mesh network nodes suffer from timing errors and delays that increase with hop count, leading to increased power consumption and potential loss of synchronization, especially in battery-powered devices.
Innovation Solution
Nodes maintain independent local network time and use periodic beacons with alternate transmission and listening windows to synchronize with neighbors, reducing power consumption and avoiding conflicts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If nodes use extended listening periods to receive timing messages from root node via tree-based hierarchy, then time synchronization accuracy is improved, but power consumption increases
Solution Approach 1:
The patent segments the time synchronization process by having each node synchronize independently with its direct parent node rather than listening to the root node. This divides the synchronization task into smaller, localized segments that consume less power while maintaining accuracy.
Solution Approach 2:
The patent implements periodic beacon transmissions from parent nodes to child nodes at scheduled intervals. This periodic action allows nodes to synchronize at regular intervals without requiring continuous extended listening periods, thereby reducing power consumption while maintaining synchronization accuracy.
2Measurement precision
If nodes transmit beacons at regular intervals to maintain time synchronization, then synchronization accuracy is improved, but beacon transmission conflicts increase
Solution Approach 1:
The patent applies preliminary action by having nodes calculate and determine their beacon transmission times in advance based on their position in the tree hierarchy and parent node's timing. This prevents conflicts before they occur by ensuring each node transmits at a predetermined non-conflicting time.
Solution Approach 2:
The patent resolves beacon conflicts by adding a temporal dimension to the synchronization process through offset timing. Nodes at different levels or positions in the hierarchy transmit beacons at different time offsets, transforming a one-dimensional conflict (same time) into a multi-dimensional solution (different times based on hierarchy position).
Data Source
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AI summary
One embodiment of the present invention sets forth a technique for performing time synchronization within a network. The technique includes detecting a first scheduling conflict between a first transmission time associated with a first periodic beacon from a first node in the network and a first listening window associated with receiving a second periodic beacon from a second node in the network. The technique also includes determining a first alternate transmission time for the second periodic beacon based on a second transmission time associated with the second periodic beacon and a position of the second node in the network and calculating a second listening window associated with transmission of the second periodic beacon from the second node at the first alternate transmission time. The technique further includes listening for the second periodic beacon during the second listening window.