Possession System: adaptation support middleware for collaborative multimedia applications in Java

Possession System is middleware which realizes a simple framework to deal with the adaptation of collaborative multimedia applications. The system is based on Possession Model which provides users with a consistent view of application components, networked sensors, and distributed devices by introducing two separated abstractions: Body and Soul. The adaptation is achieved through the changes of relationships among Bodies and Souls with a simple operation named possession. The adaptation actions can be invoked both manually and automatically by monitoring the changes of the environment underlying the applications. The middleware is applicable to adaptive systems in mobile and ubiquitous computing environments where unpredictable changes in available computing resources, device configuration, and geographics location frequently occur. We describe how collaborative multimedia applications using our middleware adaptively behave