Energy-E cient Indexing For Information Dissemination In Wireless Systems

We consider the application of high volume information dissemination in broadcast based mobile environments. Since current mobile units accessing broadcast information have limited battery capacity, the problem of quick and energy-e cient access to data becomes particularly relevant as the number and sizes of information units increases. We propose several randomized and Hu man-encoding based indexing schemes that are sensitive to data popularity patterns to structure data transmission on the wireless medium, so that the average energy consumption of mobile units is minimized while trying to access desired data. We then propose an algorithm for PCS units to tune into desired data independent of the actual transmission scheme being used. We also empirically study the proposed schemes and propose di erent transmission modes for the base station to dynamically adapt to changes in the number of data les to be broadcasted, the available bandwidth and the accuracy of data popularity patterns.