Identifying user requirements for a mobile terminal centric ubiquitous computing architecture

System level solutions affect many properties of ubiquitous applications and thus also user experience. That is why user point of view should guide the design of mobile architectures although the users will see them indirectly, via the applications. The paper describes our approach in identifying user requirements for a ubiquitous computing architecture that facilitates mobile applications sensing their environment. The sensing is based on wireless connectivity to tags and sensors in the environment. We illustrated a representative set of future applications as scenarios and proof-of-concepts and evaluated them with potential users. Scenarios were analyzed to identify generic use cases and to understand the implications of the user feedback on the architecture. Our experiences show that user requirements for system level solutions can be identified with this approach. We identified several requirements for the architecture dealing with user interaction, wireless measurements, context awareness, taking applications into use and ethical issues.