You are cordially invited by the COE Dept., to attend a Guest Seminar, on the above given title, by Dr. Mohamed Younis, Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, Sunday, 12th May, 2013, from 09:00 AM through 11:00 AM, in Building 22, Room 105.
Abstract: Recent years have witnessed an increase in applications of underwater acoustic sensor networks (UW-ASNs). UW-ASNs consist of both stationary and mobile sensor nodes that form a network in an ad-hoc manner. Sensor nodes cooperate in task execution and thus need to establish and sustain communication links in order to ensure uninterruptible interactions. Underwater communications rely on acoustic channels instead of radio channels for long range communications since radio waves quickly get absorbed in the water medium. However, the limited bandwidth of acoustic links and the slow signal propagation makes communication a challenge especially when omni-directional antennas are being employed. In addition, acoustic waves tend to take multiple paths in a shallow water environment before arriving at the receiver with combinations of reflections from the surface and the bottom. To mitigate the effect of the multipath signal propagation, directional transmission schemes have been adapted for underwater communications which requires the known position of the transmitting or receiving sensor nodes in order to establish line-of-sight (LOS) links. However, the position of underwater sensors tends to change due to water current and the explicit node mobility in some applications. Generally, when the location of the source and destination might be unknown, the sender pursues omni-direction transmission at high power and would thus inefficiently consume the node’s energy resource while reducing overall network throughput due to spectrum underutilization. To address these issues, we are developing a suite of protocols for node discovery, localization, medium access control, and routing that factor in the underwater physical layer dynamics. These protocols leverage a novel surface-based reflection scheme that enables nodes to establish non-line-of-sight (NLOS) links by reflecting acoustic transmissions on the water surface or bottom. The end result is an effective design that mitigates the effect of multipath propagation while fully utilizing the available spatial spectrum. This talk will present our surface-based communication model, give an overview of the networking protocols, and report on the on-going prototyping validation efforts.
About the speaker: Dr. Mohamed Younis is currently an associate professor in the department of computer science and electrical engineering at the university of Maryland Baltimore County (UMBC). He is also the Director of the Embedded Systems and Network lab. Before joining UMBC, he was with the Advanced Systems Technology Group, an Aerospace Electronic Systems R&D organization of Honeywell International Inc. While at Honeywell he led multiple projects for building integrated fault tolerant avionics and dependable computing infrastructure. Dr. Younis’ technical interest includes network architectures and protocols, wireless sensor networks, embedded systems, fault tolerant computing, secure communication and distributed real-time systems. He has published over 180 technical papers in refereed conferences and journals. Dr. Younis has five granted and four pending patents. In addition, he serves/served on the editorial board of multiple journals and the organizing and technical program committees of numerous conferences. Dr. Younis is a senior member of the IEEE and the IEEE communications society.