A new node coordination scheme for data gathering in underwater acoustic sensor networks using autonomous underwater vehicle

Underwater acoustic sensor network (UWSN) has many important future applications in environmental, natural resources development, and geological oceanography. The recent advancement in underwater acoustic networking technologies and autonomous underwater vehicle (AUV) technologies enables the new underwater networking paradigm of using the AUV as the mobile sink for data collection. In this paper, we propose a coordination scheme for data gathering in UWSN using AUV. The mobility of AUV makes communication between AUV and sensor nodes challenging and it is difficult to guarantee that sensor nodes will be able to come out of sleep mode for communication. With different energy consumption requirements and constraints, the operation of AUV includes sending beacon messages, channel detection, and data reception, whereas that for the underwater sensor nodes involves prolonged sleep mode with sporadic data transmission. Therefore, different cycle periods would be required for AUV and sensor nodes. A new scheme is proposed and the shortest wakeup time and optimal amount of sleeping time for sensor nodes are investigated. Moreover, we demonstrate the effectiveness of our scheme when time synchronization does not exist between AUV and sensor nodes. Furthermore, transmission power control by using received signal strength (RSS) is introduced in order to decrease energy consumption and increase communication reliability. Simulation results show that the proposed scheme with power control leads to relative low energy consumption during communication under the harsh underwater environment compared with that without power control.