Affiliations: Deakin University, School of Information Technology,
Geelong, VIC, 3217, Australia. E-mail: [email protected] | Tun Hussein Onn University of Technology, Faculty of
Information Technology & Multimedia, 86400 Parit Raja, Batu Pahat, Johor,
Malaysia | University of Malaya, Institute of Science
Mathematics, 50603 Kuala Lumpur, Malaysia
Abstract: Mobile computing has enabled users to seamlessly access databases
even when they are on the move. Mobile computing environments require data
management approaches that are able to provide complete and highly available
access to shared data at any time from any where. In this paper, we propose a
novel replicated data protocol for achieving such goal. The proposed scheme
replicates data synchronously over stationary sites based on three dimensional
grid structure while objects in mobile sites are asynchronously replicated
based on commonly visited sites for each user. This combination allows the
proposed protocol to operate with less than full connectivity, to easily adapt
to changes in group membership and not require all sites to agree to update
data objects at any given time, thus giving the technique flexibility in mobile
environments. The proposed replication technique is compared with a baseline
replication technique and shown to exhibit high availability, fault tolerance
and minimal access times of the data and services, which are very important in
an environment with low-quality communication links.