A Wireless Cache Adaptive Invalidation Algorithm In connection and reconnection periods

Abstract

The basic cache consistency strategy is the use of periodic invalidation reports (IRs) broadcast by the server. Recently, the addition of updated invalidation reports (UIR) has been proposed. The IR+UIR scheme achieves a much shorter query delay than the basic IR scheme. Previous researches were based on two impractical simplifying assumptions: 1) broadcast traffic is error-free and 2) no other downlink traffic exists in the system. IR partitioning reconstruction lifts these two assumptions on the basic IR and IR+UIR. The (IR partitioning, reconstruction) achieves the following 1) reduces the probability of corruption in IR, 2) improves channel utilization, 3) reduces the average delay in other downlink traffic. However, there are still some drawbacks. One of the drawbacks is the problem with long disconnection. The major contribution for this paper is to propose an adaptive cache invalidation report in the server either broadcasting invalidation reports segments (IRseg+UIR) or bit sequences (BSs) based on the client disconnection time while spending little uplink and downlink cost. Simulation results have shown, and minimized query delay and data packet delay and improved the number of uplink per successful query using the proposed algorithm