In the recent evolution of wireless communication technology, there has been an increasing interest in the database broadcasting system where a server periodically broadcasts contents of a database to mobile clients such as portable computers and PDAs. There are three query processing methods in the database broadcasting system: the on-demand method, the client method, and the collaborative method which we have proposed. The performance of these methods is strongly affected by environmental conditions such as query generation intervals and size of query results. Since the system condition keeps changing, it is difficult to choose the optimal method statically. In this paper, we propose an adaptive query processing method which dynamically chooses a method which gives the best performance at the moment. Our method chooses a method according to query generation intervals in order to reduce the response time and to increase the query success rate. We also show simulation results regarding performance evaluation of our method.
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