This paper introduces a comprehensive framework that allows mobile users to access a variety of services provided by their current environment (e.g. print services). Novel to our approach is that selection and execution of services takes into account the user's current context. Instead of being harassed by useless activities as service browsing or configuration issues, environmental services get seamlessly aligned to the user's present task. Thus, the challenge is to develop a new service framework that fulfils these demands. The paper proposes a document-based approach; so called Context-Aware Packets (CAPs) contain context constraints and data for describing an entire service request. The core framework, Context-Aware Packets Enabling Ubiquitous Services (CAPEUS), reverts to CAPs for realising context-aware selection and execution of services.

Context modeling and detection will play a major role for pervasive computing. This paper proposes an approach to reveal the user's context in a self-organized sensor network without a central point of control. A uniform communication scheme, referred to as Smart Context-Aware Packet's (sCAP's), allows single sensors to share sensed data and to cooperate in order to build a meaningful context model from manifold inputs. In this approach, sCAP's are injected into the sensor network by the context inquirer. In particular, sCAP's contain a retrieving plan specifying which types of sensors should be visited to obtain the desired context information. The paper concentrates on the routing concepts which allow to deal with breakdowns of sensor nodes and continuous changes of the network topology.

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We describe an architecture that allows mobile users to access a variety of services provided by pervasive computing environments. Novel to our approach is that the system selects and executes services taking into account arbitrary contextual information (e.g. location or preferences). Our architecture is based on an adaptive service interaction scheme; individual service requests are attributed by context constraints, which specify the adaption policy. Context constraints may relate to spatial or temporal concerns. We propose a document-based approach; so called Context-Aware Packets (CAPs) contain context constraints and data for describing an entire service request. Intermediary network nodes route and apply the data to services, which match the embedded constraints. Services are identified by characterizing attributes, rather then explicit network addresses. The execution of selected services may be deferred, and triggered by a specific event. Service requests carry the context of their use, therefore our system works well in environments with intermitted connectivity, less interaction with the issuing requester is required.

Abstract. Research in Ubiquitous and WearableComputing yielded several types of context-aware applications, dramatically changing the way to interact with computers. Personalizing these applications is a key concern; therefore we investigate ways to apply user modeling to the paradigm of context-aware systems. Our initial work proposes (1) a hierarchy that relates user model data to contextual information, and (2) operations for manipulating the hierarchy. Deploying the operations the hierarchy can act as a substrate for communicating the user's wishes concerning system behavior.