Coastal patrol and surveillance networks using AUVs and delay-tolerant networking

In this paper, we consider a coastal surveillance scenario, where Autonomous Underwater Vehicles (AUVs) patrol an area of interest and inspect surface ships or underwater assets passing through the area. A shore-based control center monitors the AUVs by means of delay-tolerant networking techniques. In particular, as the AUVs carry out their patrolling task, they may get in contact with one another and have a chance to exchange data about the inspected assets (identity, route followed, movement speed, etc.). Given that the area to be patrolled is usually quite large, these contacts are erratic and time-limited: this makes the AUVs and the sink a Delay-Tolerant Network (DTN). To make the communication between AUVs more effective during a contact, we propose a DTN protocol which splits the estimated contact duration between the nodes involve and enhance this protocol using an Automatic Repeat reQuest (ARQ) technique based on selective repeat for error control. Moreover, the structure of the signaling packets exchanged prior to data transmission is designed to help estimate the contact duration and thereby optimize the subsequent data packet exchange. Simulation results demonstrate that the proposed protocol outperforms other ARQ-based DTN routing protocols.