Current Projects

SCriM Project

Wireless sensor networks naturally apply to a wide range of system monitoring tasks. Meanwhile, there are obvious performance deficiencies in applying existing sensornets in mission-critical monitoring applications, where a system failure is often catastrophic. In this project we explore a database-driven approach to optimize monitoring queries in wireless sensor networks. We develop novel cross-layer optimization techniques that utilize information about how the lower network layers operate while processing the queries in critical sensor environments. Our framework enables both qualitative analysis and quantitative cost-based optimization of sensor queries.

Nebula Project

Wide Area Applications utilize a Wide-Area-Network (WAN) infrastructure e.g., the Internet, to connect a federation of hundreds of servers servicing tens of thousands of clients. The use of a public network for data delivery causes deterioration of service reliability (e.g., in the form of broken links) and performance (e.g., increased delivery time due to points of congestion in the network). Therefore, mediators over wide area applications need to provide, in addition to traditional services such as data integration, services that aim at improved reliability and reduced latency. In this project we aim at constructing profiles, information regarding servers, network, and client performance. With such profiles at hand, mediators can optimize query performance. Also, such information improves Web caching utilization, thus reducing retrieval latency, a common deficiency in contemporary wide area applications.