Supporting context awareness in ubiquitous service environments

Sammanfattning: Computing devices are becoming wireless, increasinglysmaller and embedded into other artefacts. Some of them aremobile while others are built into the environment. The noveltechnologies are also becoming more dependent of communicationwith other computing devices over different kinds of networks.These interconnected devices constitute locally distributedcomputing environments that will set new requirements on thedesign of software systems.A framework, which provides means to model and design thiskind of computing environments, is introduced under the notionof Ubiquitous Service Environments, describing locallydistributed systems with interconnected software services.Two specific problems are addressed for this kind ofcomputing environments: Firstly how to acquire and distributeinformation about a user's context in order to enable new kindsof application behaviours. The other problem that is beingaddressed concerns how to create means for context awareservice discovery, e.g. how a mobile computing device candiscover computational resources in the vicinity.The Context Shadow system is presented, which makes itpossible for services to ask questions about a person's currentcontext, and specifically about the computational services thatare relevant to that context. The system has also been extendedwith a sensor platform in order to support the deployment ofsensors used to collect context information.