Collaborative Joins in a Pervasive Computing Environment

Abstract

Locating and obtaining context sensitive information in a mobile environment has always been a challenge. This is especially true for pervasive computing environments where in addition to limited computing and battery resources, mobile devices cannot always rely on the help of a proxy-based wired infrastructure. Rather, a collaboration among peer mobile entities is required. It allows entities to obtain data that may be otherwise inaccessible due to nature of the environment and to reduce their computation cost by reusing answers generated by other peers. We introduce the problem of data interaction among peers in ad-hoc networks and propose a collaboration query processing protocol based on the principles of Contract Nets. Once an entity identi es information it needs via the help of user's pro les, our protocol enables the device to locate data sources and obtain data matching its speci c query requiring one or more data sources. We show the effectiveness of our technique through performance evaluation of entities querying for data while moving in a city-like environment.