Mobile data with time constraint over ubiquitous computing environments

This paper describes mobile services with time constraints in ubiquitous computing environments. In a ubiquitous computing environment, the need for a real-time database management model is strong, because one of the basic requirements in mobile data management is to provide real-time response to transactions of the underlying strategies. However, the resource constraints of ubiquitous computing systems make it difficult to satisfy timing requirements of supported strategies. In this paper, we study scheduling strategies for mobile data program with timing constraints in the form of deadlines. Unlike previously proposed scheduling algorithms for mobile systems which aim to minimize the mean access time, our goal is to identify scheduling algorithms for ubiquitous systems that ensure requests meet their deadlines. We present a study of the performance of traditional real-time strategies, and demonstrate that traditional real-time algorithms do not always perform the best in a mobile environment. We propose an efficient scheduling algorithm, called scheduling priority of mobile data with time constraint(SPMT), which is designed for timely delivery of data to mobile clients.