Local vs Global Policies and Centralized vs Decentralized Control in Virtual Communities of Agents

We are interested in the design of policies for virtual communities of agents based on the grid infrastructure. In a virtual community agents can play both the role of resource consumers and the role of resource providers, and they remain in control of their resources. We argue that this requirement creates a distinction between two dimensions: global vs local and centralized and decentralized control by means of policies. The providers should be enabled to specify their local policies on their own resources, but their policies should be consistent with the global policies. At the same time, some aspects of the decentralized control should be delegated to specialized providers; this delegation requires a distinction between the authorization to access a resource and a permission to do so.