Abstract
This paper presents an Agent-based Discovery and Allocation of Resources (ADAR) model for wireless grids of virtual organizations. ADAR allocates cost effective resources for the jobs in order to maximize the resource utilization. It employs resource discovery mechanism in a hierarchical fashion: firstly within a local cluster, secondly within a virtual organization if a resource is not available in the local cluster, and finally among the virtual organizations if a resource is not available within the local virtual organization. ADAR uses five types of agents namely Job Processing Agents (JPAs), Job Mobile Agents (JMAs), Resource Monitoring Agents (RMAs), Actual Organization Resource Broker Agents (AORBAs), and Virtual Organization Resource Manager Agents (VORMAs). JPA is static and executes a job within the same machine if the resources are available; otherwise it creates a JMA that carries the job requirements with it and communicates with its associated AORBA to discover the required resources. The AORBA is a static agent and discovers the optimum cost resources within its cluster. AORBA interacts with the VORMAs in case the resources are not available within a cluster. VORMA is a static agent and can interact with other VORMAs. The RMA is a static agent and monitors the resource status of a machine. The discovery results are informed to JMA, which makes the source device to migrate its job to the discovered resource. ADAR is evaluated in a simulated environment by using different wireless grid scenarios for virtual organizations. The performance parameters evaluated are: job cost function, resource utilization, bandwidth utilization, agent overheads, and resource discovery time against different mobility factors and varying system loads.