Ad-hoc Sensor Network Time Synchronization Without Central Server
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional time synchronization methods, such as RBS, require a central server for sensor network systems and are not suitable for ad-hoc type systems, leading to system scale expansion and limitations in synchronizing sensor nodes without a central server.
Innovation Solution
A network terminal configuration that creates and registers time-series data with additional time information from other nodes, allowing each node to synchronize its timer based on received data, without the need for a central server, by determining a transfer destination and correcting its time based on the number of registrations exceeding a threshold, thereby achieving synchronization in an ad-hoc network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a central server is used for time synchronization (RBS method), then time synchronization can be achieved, but system scale expands and a central server becomes required
Solution Approach 1:
The patent extracts the time synchronization function from a central server and distributes it to each sensor node. Each node independently creates time-series data and exchanges it with neighboring nodes, eliminating the need for a central server while maintaining synchronization capability.
Solution Approach 2:
Each sensor node performs time synchronization autonomously by creating its own time-series data, exchanging it with neighbors, and adjusting its timer based on received data. This self-service approach eliminates dependency on a central server and reduces system scale.
2Reliability
If a central server is used for time synchronization, then time synchronization can be achieved, but ad-hoc type systems with directly connected sensor nodes cannot use this method
Solution Approach 1:
The patent creates a universal time synchronization method that works for both centralized and ad-hoc sensor network types. By enabling direct peer-to-peer data exchange between sensor nodes, the system becomes adaptable to different network topologies without requiring a central server.
Solution Approach 2:
Instead of having a central server broadcast time information to all nodes, the patent inverts the approach by having each node broadcast its time-series data to neighboring nodes. This inversion enables ad-hoc networks to achieve synchronization without centralized control.
3Device complexity
If time-series data is exchanged among sensor nodes, then synchronization can be achieved without a central server, but the number of data exchanges increases
Solution Approach 1:
The patent segments the time synchronization process into discrete time-series data packets that are exchanged between neighboring nodes. Each node creates time-series data at predetermined intervals and exchanges it with neighbors, breaking down the synchronization task into manageable segments.
Solution Approach 2:
The patent uses time-series data as an intermediary carrier that conveys time information between sensor nodes. Instead of direct timer adjustment, nodes exchange time-series data that contains timestamp information, which then serves as the basis for synchronization.
Data Source
AI summary
A network terminal has communication section that communicates with other network terminals connected via a network, time-series data creation section that, at timing set beforehand, creates time information including a correspondence between an identification number of the own network terminal and a current time measured by a timer of the own network terminal and creates time-series data registering the time information, and additional registration section that, when the communication section receives the time-series data transmitted from another network terminal, creates time information including a correspondence between the identification number of the own network terminal and a current time measured by the timer of the own network terminal and additionally registers the time information to the time-series data received this time.