Research On Context Aware Model In Smart Moving Space

Ubiquitous Computing(UC) is a new area of computing which aims to allow users to access and use information and service everywhere and anytime with purpose to enforce significantly human active. The provided services are"hidden"into the environment. Within this environment the served activities are conducted and are provided in an intelligent, adaptable, continual, distinctive and secure way. Therefore, economically, it's difficult to provide computing devices every corner of the world. In view of this, people are searching for method to achieve ubiquitous computing among a small circle. Smart pace is embodiment of UC in partial physical space. Ubiquitous computing system could not be a global unifying system. It should consist of many separate smart spaces. In real life , people could not be limited to living in a single smart space. They always travel to and fro between multiple smart spaces. Context awareness computing plays a decisive role in smart space and embodies the intelligence of it.This dissertation mainly deals with the study of context awareness computing in ubiquitous environment. Present studies about basic framework of single smart space are mostly limited to special application. Then based on survey, this dissertation summarized the general context aware architecture,proposed UPESCM which is a high level model of context, and presented a general context aware framework for single smart space.In order that applications can across among smart spaces, we have done much research on smart moving space. This dissertation presents a context aware model for smart moving space by expanding the presented context aware framework for single smart space to solve the privacy protecting, semantic matching, and timeliness problems. Timeliness should run through the hole context transaction process. In smart moving space, the time cost of processing context concentrates on context dissemination, reasoning and semantic matching. This dissertation researched on the context dissemination timeliness. The congestion of context dissemination consists in wireless data transmission. So the key of context dissemination timeliness is to reduce the quantity of data transmission. This dissertation use traditional cache technology to import low context cache module in context aware framework. The cache module saves low context which changes imperceptibly.Finally, for cache management, this dissertation proposed context cache replacement arithmetic(RBCCRA) to improve hit rate. The simulated experiment shows that compared to LRU RBCCRA can improve the cache hit rate.