Wireless Sensor Network, 2017, 9, 1-15 http://www.scirp.org/journal/wsn ISSN Online: 1945-3086 ISSN Print: 1945-3078 DOI: 10.4236/wsn.2017.91001 January 17, 2017 Controlled Mobility Time Synchronization for WSNs Gopal Chand Gautam, Narottam Chand Kaushal Department of Computer Science & Engineering, National Institute of Technology Hamirpur, Hamirpur, India Abstract One of the important aspects in wireless sensor networks is time synchroniza- tion. Many applications such as military activity monitoring, environmental monitoring and forest fire monitoring require highly accurate time synchro- nization. Time synchronization assures that all the sensor nodes in wireless sensor network have the same clock time. It is not only essential for afore- mentioned applications but it is mandatory for TDMA scheduling and proper duty cycle coordination. Time synchronization is a challenging problem due to energy constraints. Most of the existing synchronization protocols use fixed nodes for synchronization, but in the proposed synchronization, algorithm mo- bile nodes are used to synchronize the stationary nodes in the sensing field. In this paper, we propose a new time synchronization algorithm, named controlled mobility time synchronization (CMTS) with the objective to achieve the higher accuracy while synchronizing the nodes. The proposed approach is used in this paper to synchronize the nodes externally by using the mobile nodes. Simula- tion results exhibit that proposed controlled mobility time synchronization in- creases the synchronization precision and reduces the energy consumption as well as synchronization error by reducing the collisions and retransmissions. Keywords Wireless Sensor Network, Time Synchronization, Mobility, Offset, Energy 1. Introduction Revolutionary technological changes in the field of microelectronics and wireless communications have resulted in the emergence of wireless sensor networks (WSN). The network is composed of numerous motes equipped with miniature sensors. The advantageous features of these motes are low cost, small size, mul- ti-functionality and mobility. In modern era, wireless sensor networks have grown in popularity and are being used in various applications such as target How to cite this paper: Gautam, G.C. and Kaushal, N.C. (2017) Controlled Mobility Time Synchronization for WSNs. Wireless Sensor Network, 9, 1-15. http://dx.doi.org/10.4236/wsn.2017.91001 Received: December 1, 2016 Accepted: January 14, 2017 Published: January 17, 2017 Copyright © 2017 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access