In grid computing, the grid information service (GIS) plays an important role in grid resource discovery, registry, and indexing. The resource monitoring and discovery service (MDS) in GIS provides a set of messages to get the status information of resource providers and keeps monitoring on them. Traditional resource monitoring and discovery schemes for wired grids are not directly applicable to wireless grids due to the characteristics of them, such as frequent information update, short-lasting power source, and limited computing capacity. In this paper, we propose a network layer resource monitoring and discovery service (NL-MDS) scheme. It is an ad-hoc routing protocol embedded method for wireless grids. The resource types and status information of resource providers are piggybacked on the message extensions of the ad-hoc on-demand distance vector (AODV) routing protocol. Each client, which needs resources, can perform a fast look-up for resource providers in the proposed resource table. We have compared NL-MDS with WGMDS (Wireless Grid Monitoring and Discovery Service), an extension of MDS in the Globus Toolkit, to evaluate the number of control packets and the discovery completion time. Simulation results show for nodes from 10 to 50, NL-MDS can reduce the number of control packets from 23% to 2%, and decrease the discovery completion time on average by 50% compared to WGMDS. Therefore, the proposed lightweight resource monitoring and discovery scheme can support a fast resource monitoring and discovery service with low overhead on wireless grids, and is suitable for wireless grids in temporary or urgent needs.
