In this paper, we propose a reinforcement learning (RL) based Medium Access Control (MAC) protocol with dynamic transmission range control (TRC). This protocol provides an adaptive, multi-hop, energy-efficient solution for communication in underwater sensors networks. It features a contention-based TRC scheme with a reactive multi-hop transmission. The protocol has the ability to adjust to network conditions using RL-based learning algorithm. The combination of TRC and RL algorithms can hit a balance between the energy consumption and network performance. Moreover, the proposed adaptive mechanism for relay-selection provides better network utilization and energy-efficiency over time, comparing to existing solutions. Using a straightforward ALOHA-based channel access alongside “helper-relays” (intermediate nodes), the protocol is able to obtain a substantial amount of energy savings, achieving up to 90% of the theoretical “best possible” energy efficiency. In addition, the protocol shows a significant advantage in MAC layer performance, such as network throughput and end-to-end delay.

This paper describes the simulation of a fleet of Autonomous underwater vehicles (AUVs) used for plume detection and plume source tracking using ROS and Gazebo. This is achieved by the integration of underwater vehicle simulation tools that model the vehicle, plume, underwater environment, and its dynamics. The plume tracing is done by a trajectory planner, or a leader robot followed by a group of robots planning their positions in a geometric pattern. The results discussed in this paper demonstrate the platform that has been setup for advanced applications using a fleet of AUVs.

In this demo, we showcase the recent progress of μ-Net, a community-shared, open-source, open-architecture infrastructure that supports acoustic communication, underwater networking, and marine robotics. Specifically, We will demonstrate the integration of u-Net and a newly developed acoustic modem. In the demo, multiple ROS-running systems are able to form an underwater wireless network and communicate using acoustic modems.