Negotiating Agreements Using Policies in Ubiquitous Computing Scenarios

The emerging ubiquitous computing vision is characterized by decentralized and ad hoc interoperation among devices and networks for access to services. Interacting devices or groups have highly heterogeneous resources and security and privacy concerns, and invariably belong to different security or administrative domains. Flexible and automated mechanisms are needed to achieve effective cross-domain interoperation that leads to a service or resource sharing agreement. We describe how policies representing system state, requirements and intent can be used to negotiate agreements between mutually unknown and untrusted systems that differ widely in their characteristics. Our negotiation protocol uses a small number of message types, which we have found to be sufficient for supporting a wide variety of application scenarios that occur on the Web, and that will likely be important in the ubiquitous computing environments of the future.