للكاتبين :
Ali I. El-Desouky, Hesham A. Ali, Engy A. El-Shafaiy
Computers and Systems Department, Faculty of Engineering, Mansoura University, Egypt
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 but, there are still some
drawbacks. One of the drawbacks is the problem with long disconnection. So The adaptive
invalidation report algorithm (AIR) can deal with this problem but (AIR) broadcasting
invalidation report segments (IRseg+UIR) or bit sequences (BSs) with fixed window. The
main contribution for this paper is to propose adaptive cache invalidation report that
generates a IR either broadcasting invalidation reports segments (IRseg+UIR) or bit
ADAPTIVE CACHE INVALIDATION REPORT ALGORITHM BASED ON ADAPTIVE WINDOW(AIRA-AW) FOR CONNECTION AND
RECONNECTION PERIODS IN MOBILE ENVIRONMENT
sequences (BSs) with adaptive window at the server, This algorithm is based on a
combination of the advantages of Invalidation Report segments (IRseg+UIR) and bitsequences
(BSs) with adaptive window. Such algorithm will help in improving mobile
caching and reducing the uplink and downlink cost . Simulation results are compared against
the most recent work in this area. This comparison show that, using of the proposed algorithm
has a significant impact on minimizing query delay and data packet delay, moreover it will improve
the number of uplink per successful query.