Possession System: middleware for adaptive multiuser applications in a mobile environment

Describes the design and implementation of a middleware system named the Possession System. The system is designed based on the “possession model”, which provides users with a consistent view of application components, networked sensors and distributed devices by introducing two separate abstractions: “body” and “soul”. The Possession System realizes a simple framework to deal with the adaptation of distributed multi-user applications by changing the relations among “bodies” and “souls”. Furthermore, it enables users to interact with system components with a simple operation named “possession”. Distributed multi-user applications built on top of our middleware realize adaptive behavior, which is achieved by a mechanism combining system events with various behavioral changes of application components, including the migration of components. The middleware is applicable to adaptive systems in mobile and ubiquitous computing environments where unpredictable changes in the available computing resources, device configuration and geographic location frequently occur. We describe how multi-user applications using our middleware behave adaptively