Proxy agent based replication control model for wireless internet

Mobile computing allows users to request critical information and receive swift responses at any places, but mobile users could suffer from unreliable and ill-timed services due to the characteristics of wireless media. One way that reduces possibility of the unsatisfactory services is data replication. Data replication, however, inevitably induces the overhead of maintaining replica consistency which requires more expensive synchronization mechanism. We propose a new replicated data management scheme in distributed mobile environment. In order to alleviate negative impact of synchronization message overhead in fault-prone mobile environment, we devise a new replication control scheme called proxy quorum consensus (PQC). PQC minimizes the message overhead by coordinating quorum access activities by means of proxy mediated voting (PMV) which exploits reliable proxy hosts instead of unreliable mobile hosts in voting process. We also propose a simulation model to show the performance of PQC. Based on the results of the performance evaluation, we conclude that PQC scheme outperforms the traditional schemes.