Abstract
In the research area of information dissemination, many approaches are proposed to schedule data items for broadcasting. However, the issues of accessing multiple data items in a query are less discussed. In this paper, we propose a push-pull strategy for answering multiple data item queries in mobile environments. Mobile clients retrieve data items either from the broadcast channel or on-demand channel acknowledged by the server. Two issues are investigated in this paper. Deciding the content of the broadcast channel is first discussed. Second, the problem of scheduling the data items is presented. We propose three greedy methods to adjust the content of the broadcast channel according to the queries from the clients. Besides, we propose two methods to schedule the data items frequently accessed in the queries on the broadcast channel. Experiments are performed to compare the effect of our proposed greedy methods. The experimental results show that our data scheduling methods can reduce the average access time without increasing much processing time.