An efficient AUV-aided data collection in underwater sensor networks

From the view of routing protocols in Underwater Sensor Networks (UWSNs), mobile data-gathering mechanisms using Autonomous Underwater Vehicle (AUV) have received significant attention because of data collection capability via short-range communications. In this paper, a new Cluster-based AUV-aided Data Collection scheme (CADC) for large-scale UWSNs is proposed to make a trade-off between energy saving and data gathering latency. Our scheme consists of three phases: discovery phase, clustering phase, and data gathering phase. Neighbouring information is exchanged and then collected by AUV during the discovery phase. The collected information is used in the clustering phase in order to determine the cluster heads and members. Then, the AUV tour is planned such that all cluster heads are visited while shortening the tour length of the AUV. To cluster the sensors and cover their heads with the shortest possible tour, we first propose an optimal algorithm to find the global optimal solution, and then propose an efficient algorithm to obtain the near-optimal solution in the less computational time. CADC is scalable and also applicable in both connected and disconnected networks. In terms of energy-latency trade-off, CADC can effectively keep the tour length short while prolonging the network lifetime compared to those of mobile data-gathering approaches. The effectiveness of CADC is validated through an extensive simulation study which reveals the performance improvement in the packet delivery ratio, energy saving, and data gathering latency.