Abstract

Applications offered to end-users as value added services, or more simply services, are crucial to the success of future generations mobile communication systems. One important capability that will enable novel services is ambient awareness. The awareness of ambient information is usually acquired by a network of sensors and is related to end-users' context in terms of situation and environment. There exist several frameworks for the dissemination of sensor data to end-user applications. They range from low-level APIs to databases and include Web services. This thesis advocates Web services for the dissemination of ambient information to I-centric applications. It shows the shortcomings of the current dissemination frameworks and demonstrates the promises of Web services as a framework. High level of abstraction offered to application developers and ease of integration are among the key motivating factors. A set of Web services for bridging these applications and sensor networks are defined and implemented. They provide ambient information such as location, velocity, environmental data, physical presence and proximity. A generic functional architecture of the framework and a model for ambient information provide sensor interoperability and are implemented as part of the thesis. To ultimately show the feasibility of the Web service based framework, performance measurements are conducted with respect to network load and response time. The analysis shows that response time is increased while network load may decrease or increase depending on the type of ambient information requested. Ultimately, it is a small price to pay for benefiting from sensor interoperability and ease of application development.