Maintain cache consistency of mobile database using dynamical periodical broadcast strategy

In mobile database, in order to reduce the contention of limited network bandwidth by mobile computers and improve availability of local data, frequently, and used data are cached locally. How to effectively maintain cache consistency is a hot research topic. In this paper, we propose strategies to maintain cache data consistency, which are, based on updating frequency of data items, to broadcast dynamically using variant period, to broadcast updating messages instead of invalidation messages, to use substitution strategy based on semantically cached data units, to maintain cache consistent based on historical report after mobile computer reconnects. Finally we analyze performance of the strategies.