An analysis of selective tuning schemes for nonuniform broadcast

摘要

Broadcasting is an effective means of disseminating information in a wireless environment to a large number of clients with powerful palmtops. However, it requires the clients to be actively listening to the communication channels for the desired information. Because of the high power consumption of the active mode, it is crucial for the battery-operated palmtops to conserve their energy in order to extend their effective battery life. This calls for selective tuning mechanisms that allow the clients to operate in the less energy-consuming doze mode, and to operate only in active mode when the desirable portion of the information is broadcast. Most of the existing work focuses on uniform broadcast. In practice, only a small amount of information is highly in demand by a large number of clients while the remainder is less popular. This nonuniform access pattern poses several new issues. In this paper, we examine these issues and look at how a nonuniform broadcast can be organized for selective tuning by the clients. We describe several indexing schemes to facilitate selective tuning which are variations of existing techniques on uniform broadcast. We analyze the performance of the schemes based on the average tuning time and average access time.