Abstract:
UnderWater Acoustic Sensor Networks (UW-ASNs) consist of sensors deployed to perform collaborative monitoring tasks over a given volume of water. This talk focuses on the fundamental key aspects of underwater acoustic communications, on reference communication architectures for underwater sensor networks, and on efficient sensor communication protocols for the underwater environment. Specifically, a realistic acoustic model characterizing the channel utilization efficiency is introduced. The model allows setting the optimal packet size for underwater communications given monitored volume, density of the sensor network, and application requirements. In addition, two efficient distributed routing algorithms for delay-insensitive and delay-sensitive applications are discussed. The routing solutions allow each node to select its next hop with the objective of minimizing the energy consumption, while taking the different application requirements and the acoustic channel characteristics into account. A novel distributed MAC protocol developed for UW-ASNs is also presented. It is a transmitter-based CDMA protocol and incorporates a unique closed-loop distributed algorithm to set the optimal transmit power and code length. Simulation results show that the proposed MAC protocol manages to achieve high network throughput, low channel access delay and low energy consumption, and that it outperforms competing MAC schemes. Finally, the talk motivates the need to design an energy-efficient cross-layer protocol suite that integrates different communication functionalities to achieve high performance channel access, routing, event transport reliability, and data flow control in underwater acoustic sensor networks.

Bio:
Dario Pompili received his Laurea degree (integrated B.S. and M.S.) in Telecommunications Engineering in 2001, summa cum laude, from the University of Rome "La Sapienza", Italy, with a thesis titled "Quality of Service in a Broadband Satellite Network for Internet Access". From June 2001 he had been working at the University "La Sapienza" on the BRAHMS (BRoadband Access for High speed Multimedia via Satellite) and SATIP6 (SATellite broadband multimedia system for IPv6) projects, promoted by the Information Society of Technologies and financed by the European Union. In 2001-2004 he had been a System Engineering Ph.D. candidate at the University of Rome "La Sapienza", where in December 2004 he defended his Ph.D. thesis entitled "Demand-Assignment Mechanisms in GEO Satellite Systems and Resource-Optimized Algorithms for Multicast Applications in Wired and Wireless Networks". In 2003 he worked on sensor networks at the Broadband and Wireless Networking Laboratory (BWN-lab), Georgia Institute of Technology, directed by Dr. I. F. Akyildiz, as a visiting researcher. In 2004 he started his Ph.D. in the School of Electrical and Computer Engineering at the Georgia Institute of Technology, under the guidance of Dr. I. F. Akyildiz. He is expected to receive his Ph.D. in June 2007. In 2005, he received the Broadband & Wireless Laboratory Researcher of the Year for outstanding contributions and professional achievements. His main research interests are in Multimedia Ad Hoc and Sensor Networks, Underwater Sensor Networks, Wireless Sensor and Actor Networks, Overlay Networks, Wireless Communications, Traffic Engineering, and Optimization.