Through a thorough review of existing literature, and extensive study of two large ubicomp systems, problems are identified with current mobile design practices, infrastructures and a lack of required software. From these problems, a set of guidelines for the design of mobile, peer-to-peer, context-aware systems are derived. Four key items of software infrastructure that are desirable but currently unavailable for mobile systems are identified. Each of these items of software are subsequently implemented, and the thesis describes each one, and at least one system in which each was used and trialled. These four items of mobile software infrastructure are: An 802.11 wireless driver that is capable of automatically switching between ad hoc and infrastructure networks when appropriate, combined with a peer discovery mechanism that can be used to identify peers and the services running and available on them. A hybrid positioning system that combines GPS, 802.11 and GSM positioning techniques to deliver location information that is almost constantly available, and can collect further 802.11 and GSM node samples during normal use of the system. A distributed recommendation system that, in addition to providing standard recommendations, can determine the relevance of data stored on the mobile device. This information is used by the same system to prioritise data when exchanging information with peers and to determine data that may be culled when the system is low on storage space without greatly affecting overall system performance. An infrastructure for creating highly adaptive, context-aware mobile applications. The Domino infrastructure allows software functionality to be recommended, exchanged between peers, installed, and executed, at runtime.
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