An Optimal Beacon Selection Technique for Time Synchronization in Underwater Acoustic Wireless Sensor Networks
M. Saranya Nair1, K. Suganthi2
1Prof. M. Saranya Nair, Assistant Professor, School of Electronics Engineering, Vellore Institute of Technology, Chennai, India.
2Dr. K. Suganthi, Assistant Professor (Sr), School of Electronics Engineering, Vellore Institute of Technology, Chennai, India.

Manuscript received on 12 April 2019 | Revised Manuscript received on 17 May 2019 | Manuscript published on 30 May 2019 | PP: 2445-2449 | Volume-8 Issue-1, May 2019 | Retrieval Number: A2207058119/19©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Recently, Underwater Acoustic Sensor Networks (UASNs) have been developed as a significant research area since it is marked that a huge amount of unexploited resources lies under water which covers about 70% of the Earth. UASN is an effective combination of wireless, acoustic and sensor technology having the capabilities of smart sensing, intelligent computing and communication. In UASNs, the time associated with the sensed data is very critical for further data processing, which makes the time synchronization in UASNs as an essential requirement for many applications. Regrettably, GPS signaling cannot be used for underwater scenarios which pave the necessity to develop alternative synchronization approaches in UASNs. Beacon based synchronization approaches have been emerged as an efficient technique in UASNs, but in order to enhance the accuracy of such methods, the selection of an Optimal Beacon set is needed. In this paper, we are proposing an Optimal Beacon Selection Technique (OBST) for achieving accurate clock synchronization in UASNs. In our approach, a mobile AUV guided by a pre-defined trajectory will be used to generate a set of Virtual Beacons (VBs). The proposed beacon selection method addresses the physical, data link and network layer issues by selecting optimal beacon based on the Received Signal Strength (RSS) values from VBs, distance of separation from target node to be synchronized, residual energy and the received time stamps. An analytical model for optimal beacon selection was derived and analyzed based on the synchronization error and percentage of synchronization for dense and sparse networks. From the simulation results, it is found that the proposed optimal beacon selection technique outperforms the existing approaches in terms of synchronization accuracy, network cost and communication overhead.
Index Terms: Optimal Beacon, Time Synchronization, Received Signal Strength, Timestamp.

Scope of the Article: Optimal Design of Structures