Cache invalidation for updated data in ad hoc networks

Recent advances in computer and wireless communication technologies have led to an increasing interest in ad hoc networks which are constructed of only mobile hosts. In this paper, we propose two cache invalidation methods in ad hoc networks where each data item is updated at inconstant intervals. In the first method, when a mobile host holding an original data item updates the data item, it broadcasts an invalidation report to all connected mobile hosts. In the other method, when two mobile hosts are connected, they rebroadcast invalidation reports received before to newly connected mobile hosts. Our proposed methods reduce the number of accesses to invalid cached data items which have been updated and the number of roll backs caused by such invalid accesses. We also show the result's of simulation experiments regarding the performance evaluation of our proposed methods.