tailieunhanh - REED: Robust, Efficient Filtering and Event Detection in Sensor Networks

A widely cited application of sensor networks is event- detection, where a large network of nodes is used to iden- tify regions or resources that are experiencing some phe- nomenon of particular concern to the user. Examples in- clude condition-based maintenance in industrial plants [14], where engineers are concerned with identifying ma- chines or processes that are in need of repair or adjustment, process compliance in food and drug manufacturing [25], where strict regulatory requirements require companies to certify that their products did not exceed certain environ- mental parameters during processing, and applications centered around homeland security, where shippers. | REED Robust Efficient Filtering and Event Detection in Sensor Networks Daniel J. Abadi Samuel Madden and Wolfgang Lindner MIT CSAIL dna madden wolfgang @ Abstract This paper presents a set of algorithms for efficiently evaluating join queries over static data tables in sensor networks. We describe and evaluate three algorithms that take advantage of distributed join techniques. Our algorithms are capable of running in limited amounts of RAM can distribute the storage burden over groups of nodes and are tolerant to dropped packets and node failures. REED is thus suitable for a wide range of event-detection applications that traditional sensor network database and data collection systems cannot be used to implement. 1. Introduction A widely cited application of sensor networks is eventdetection where a large network of nodes is used to identify regions or resources that are experiencing some phenomenon of particular concern to the user. Examples include condition-based maintenance in industrial plants 14 where engineers are concerned with identifying machines or processes that are in need of repair or adjustment process compliance in food and drug manufacturing 25 where strict regulatory requirements require companies to certify that their products did not exceed certain environmental parameters during processing and applications centered around homeland security where shippers are concerned with verifying that their packages and crates were not tampered with in some unsavory manner. A natural approach to implementing such systems is to use an existing query-based data collection system for sensor networks. Through queries a user can ask for the data he or she is interested in without concern for the technical details of how that data will be retrieved or processed. A number of research projects including Cougar 31 Directed Diffusion 12 and TinyDB 19 20 have advocated a query-based interface to sensornets and several implementations of query systems have