A Data Replication Scheme based on Primary Copy for Ensuring Data Consistency in Mobile Ad hoc Networks

摘要

A mobile ad hoc network (MANET) is a multi-hop wireless network capable of autonomous operations. Since MANET causes frequent network partitions, a data replication is considered as a way to increase the data accessibility and the availability of transaction processing. If the database is replicated among mobile hosts, additional energy is required to keep data consistency. We propose a data replication scheme for MANET, which provides data consistency and increased number of successful committed transactions reducing energy consumption. The proposed scheme updates the data in the primary copy, which guarantees the latest value of the data item. If an application wants the latest version of data, it should refer to the primary copy; otherwise it accesses the local copy of the data. When the application does not require the latest version, our scheme approves the access of the data item to the local copy. It can improve the energy efficiency by reducing the additional number of messages to maintain data consistency and to query data. Furthermore we can expect the performance improvement by alleviating the message traffic or by reducing the number of aborted transactions due to network partitions because the proposed scheme validates any conflicts only on the host of the primary copy.