A Time Synchronization Method for Underwater Sensor Networks

Abstract

The invention discloses a network time synchronization method for an underwater sensor. The network time synchronization method comprises of the steps that network nodes of the underwater sensor are arranged, a standard time node is fixed, a node to be synchronized moves along with the ocean current, the standard time node sends a long data packet comprising sending time, and the node to be synchronized continuously sends a plurality of short data packets comprising sending time; the last time when the standard time node encounters with the data packets sent by the node to be synchronized before information sent by the standard time node arrives at the node to be synchronized is determined according to the conflict of the data packets sent by the standard time node and the node to be synchronized at the receiving end of the node to be synchronized; the last time serves as a reference time point, and an equation is written; the time when the node sends information is adjusted, the steps are repeatedly carried out to obtain the other equation, and time migration and the drift rate are worked out by combining the two equations into a set of linear equation in two unknowns. According to the method, the encounter and conflict of the data packets are utilized, the effect on synchronous precision from node movement is overcome, cost is low, special arrangement and additional equipment are not needed, and the method is simple, reliable and high in adaptability.

Description

technical field [0001] The invention relates to a sensor network time synchronization method, in particular to an underwater sensor network time synchronization method. Background technique [0002] The role of the ocean in life is becoming more and more significant, and the underwater sensor network has received more and more attention, and is widely used in environmental monitoring, pollution monitoring, tracking and positioning and other fields. The time of the sensor node is controlled by the internal clock, and the internal clock is related to the frequency of the oscillator. Due to hardware, manufacturing process and other reasons, different nodes have different frequency changes, so there are different internal clocks, resulting in the time of different nodes. out of sync. Time synchronization is one of the key technologies of underwater sensor networks. It is meaningful to match the data collected by sensor nodes with time information. It is also the basis for the r...

AI Technical Summary

Problems solved by technology

[0008] D-Sync uses Doppler frequency shift for time synchronization. It needs to use Doppler frequency shift measurement value and node speed to calculate propagation delay. The calculation process is complicated, and Doppler frequency shift requires special equipment to measure

[0009] To sum up, it can be seen that the current main algorithms have their own problems. How to eliminate the influence of node movement does not require special deployment and additional hardware, nor does it require node location information for underwater sensor network time synchronization. method has not yet been reported

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