Liebe Kolleginnen und Kollegen, liebe Mitarbeiter, liebe Studierende, hiermit lade ich Sie herzlich zu unserem Informatik-Kolloquium am 31.05.2010 um 17:15 h in Raum A 5 C 013 ein. Es spricht Professor Dr. Siva Ram Murthy (Indien) zum Thema Information Discovery in Wireless Sensor Networks A Wireless Sensor Network (WSN) consists of a large number of tiny, battery operated, possibly mobile, self adjusting nodes with limited on-board processing, environmental sensing, and wireless communication capabilities. Apart from sensor nodes, a typical WSN consists of one or more sink nodes. Sink nodes are powered, and they are storage points for most of the data emerging from environmental sensing of sensor nodes. We consider the problem of information discovery (also referred as query processing or searching) in pull-based unstructured WSNs. In pull WSNs, the sink node sends queries for the required information, and in unstructured WSNs, the search initiator has no clue about any of the locations of target information and search proceeds blindly. In the existing proposals, the cost of search (in terms of number of transmitted bytes) increases with an increase in the density of the WSN. This limits the scalability of these protocols, especially for densely deployed WSNs. Even in the case of sparse WSNs, the cost incurred by these protocols is huge, making them infeasible for applying to energy-constrained networks like WSNs. We propose Increasing Ray Search (IRS) and Coverage-Based Expanding Ring Search (CERS) protocols for energy-efficient and scalable search in dense WSNs. IRS and CERS are based on the principles of area coverage and trajectory-based forwarding. These protocols assume location awareness for sensor nodes, and they are applicable to dense WSNs. We also propose Level Biased Random Walk Search (LBRW) and Several Short Random Walks Search (SSRW) protocols for energy-efficient and scalable search in WSNs. LBRW and SSRW do not assume location awareness for sensor nodes and work well for both sparse as well as dense WSNs. Bio: Siva Ram Murthy received his Ph.D. degree in Computer Science from the Indian Institute of Science, Bangalore and is currently a Professor in the Department of Computer Science and Engineering at IIT Madras, India. He is the co-author of the textbooks "Resource Management in Real-time Systems and Networks" (MIT Press, Cambridge, Massachusetts, USA), "WDM Optical Networks: Concepts, Design, and Algorithms" (Prentice Hall, Upper Saddle River, New Jersey, USA), and "Ad Hoc Wireless Networks: Architectures and Protocols" (Prentice Hall, Upper Saddle River, New Jersey, USA). Prof. Murthy is a Fellow of the Indian National Academy of Engineering, an Associate Editor of IEEE Transactions on Computers, and a Subject Area Editor of the Journal of Parallel and Distributed Computing. -- Prof. Dr. Wolfgang Effelsberg Tel: +49 621 181 2600 Praktische Informatik IV Fax: +49 621 181 2601 University of Mannheim effelsberg(a)informatik.uni-mannheim.de 68131 Mannheim, Germany pi4.informatik.uni-mannheim.de/~effels