Performance Evaluation and Optimization of Wireless Sensor Networks

A wireless sensor network (WSN) is an ad-hoc network composed of small sensor nodes deployed in large numbers to sense the physical world. Wireless sensor networks have very broad application prospects including both military and civilian usage. They include surveillance, tracking at critical facilities, or monitoring animal habitats. Sensor networks have the potential to radically change the way people observe and interact with their environment. With current wireless sensor network technology, people will gain advanced knowledge of physical and social systems, and the advent of a ubiquitous sensing era is coming. In-network processing or data aggregation is an essential function of WSNs to collect raw sensory data and get aggregated statistics about the measured environment, and help queries capture the major feature or changes of the measured systems. As more and more applications of WSNs collect sensitive measurements of people's everyday life, privacy and security concerns draw more and more attention. If privacy of sensory content is not preserved, it is not feasible to deploy the WSNs for information collection. On the other hand, if integrity of the collected sensory information is not protected, no queries or users can trust and/or use the collected information. Hence, two important issues should be addressed before wireless sensor network systems can realize their promise in civilian applications: (1) protect data privacy, so the deployment of the wireless sensor network systems is feasible; (2) enforce integrity, so users can trust the collected or aggregated information.