• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.68-71
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• 2018

In this paper, we propose a synchronization protocol for underwater acoustic networks which aims to minimize the effects of long propagation delay and uncertain delay variations and employs packet train scheme with considering low data rate. The proposed protocol uses an one-way delay measurement method by transmitting consecutive packets and acquires synchronization only considering propagation delay variations by calculating packet arrival time differences. We perform simulations under various network conditions, such as node mobility, time interval for packet transmission, network range, and elapsed time after synchronizing. The simulation results shows the superiority of our protocol, compared with a previously proposed protocol.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.268-273
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• 2015

Recently many countries are researching actively underwater sensor networks for securing ocean resources and changes of ocean environment in all over the world. Current the commercial modem are not suitable because it has characteristics of long distance, higher price, larger power consumption with the special object mainly. In this paper, a low power and compact underwater communication modem which is suitable for underwater sensor networks is implemented. It is comprised by using a simple analog circuit for non-coherent BFSK modulation method, ultra low power MCU and orthogonal codes with a less operation and a simple implementation. It was experimented an underwater communication using our modem in a water tank and open sea farms. It communicates fewer than $10^{-4}$ bit error rate.