Integrated Systems for the Marine Environment

The EU-funded project UAN (Underwater Acoustic Network) was aimed at conceiving, de-veloping and testing at sea an innovative and operational concept for integrating in a unique communication system underwater and above water sensors to protect o↵-shore and coastline critical infrastructures. This work gives details on the underwater part of the project. It in-troduces a set of original security features and gives details on the integration of autonomous underwater vehicles (AUVs) as mobile nodes of the network and as surveillance assets, acous-tically controlled by the command and control center to respond against intrusions. In the field results are given of the final UAN project sea trial, UAN11, held in May 2011 in Norway. During the experimental activities, a UAN composed of four fixed nodes, two AUVs, and one mobile node mounted on the supporting research vessel, was continuously operated and inte-grated into a global protection system. In this article the communication performance of the network is reported in terms of round trip time, packet loss, and average delivery ratio. The major results of the experiment can be thus summarized: the implemented network structure was successful in continuously operating over five days with nodes seamlessly entering an