Design and implementation of mobile grid middleware for handsets

This paper proposes mobile grid middleware based on an adaptive QoS framework to conceal the instability and resource constraints of mobile server hosts (MSHs). In a mobile grid system, data and codes on an MSH are replicated and synchronized on a fixed grid proxy for enhanced availability. However, operation time of MSH is limited by battery consumption due to the synchronization needed to maintain the freshness of replicas and the session management needed to maintain responsiveness of the MSH. According to application QoS requests, the framework optimizes synchronization scheduling and polling intervals to maximize sustainability. It also adapts to dynamic resource changes including low residual battery and poor wireless connectivity, by decreasing the target QoS and by reducing the aggregation period for synchronization. We built a prototype of mobile grid middleware on a J2ME handset and grid proxy on PC running Globus toolkit. Experiments showed that the framework enables MSH to increase its operation time while meeting diverse application QoS requests.