Due to the growth in ubiquitous computing technology in the past few years, the need for context-aware service discovery across wide area networks is becoming prevalent. We propose GloServ, which is a global service discovery architecture that locates services throughout wide and local area networks. It supports services encompassing different domains such as events, people or places. Services can be described semantically using the resource description framework (RDF) and can be queried using the RDF query language (RQL). GloServ hierarchically defines services using RDF schemas and assigns each service a URI according to its location within the hierarchy. The hierarchical architecture for GloServ is similar to how domain names are categorized in DNS. Service discovery can either be initiated by the user or by the system. For automated service discovery, users are detected with sensors and are presented with services available according to their preferences. Graphical user interfaces for querying data is dynamically generated through the processing of RDF data.

Ubiquitous computing envisions an environment where physical and digital devices are seamlessly integrated. Users can access their applications and data anywhere in the environment. Applications are not bound to any single device and can migrate with the user to different environments. Therefore, application mobility is an important aspect of ubiquitous computing. We consider the problem of migrating applications across different ubiquitous computing environments (i.e. across different rooms, buildings or even cities). Migration is a tough problem because different environments have different resources (devices or services) available. The context of the environments may be different as well. Hence, mobile applications must adapt to changing contexts and resource availabilities as they migrate from one environment to the next. We introduce the notion of polymorphic applications, where applications can change their structure in order to adapt to different environments. While the structure of polymorphic applications can change during migration, the functionality and the state of the application are preserved as far as possible. This enables users to perform the same tasks as they move from one environment to the next, seamlessly. We make use of ontologies to ensure that the initial and final structures of a migrating application are semantically similar in terms of functionality and behavior. This paper describes our framework for enabling mobile polymorphic applications.

We present a framework for agreements in pervasive environments called the Universal Pervasive Transaction Framework (UPTF) for parties transacting in wireless insecure environments using mobile devices. We discuss one type of such agreement with commercial interest, namely mobile payments from a payer to a payee. We have implemented two complete systems for purchasing and payment with mobile devices utilizing UPTF. The first introduces a special purpose, new mobile device called the Universal Pervasive Transaction Device (UPTD) and the second utilizes J2ME-capable mobile phones.

Existing solutions for QoS-aware routing in mobile multihop networks attempt to discover a QoS-satisfactory route for the user at the user's current location. If a suitable route is not available at the current location, the user is denied access. This approach does not take advantage of the special characteristics of mobile multihop networks. That is, users in these networks are mobile and their connectivity is dependent on their location and the locations of other users. By changing their location, users can alter their connectivity characteristics and potentially obtain better service from the network. In this paper, we propose enhancing QoS-aware routing protocols to take advantage of this characteristic. With our solution, if a satisfactory route is not available at the user's current location, the protocol discovers a nearby location where a better route is available. The user can then choose to move to the suggested location to improve the received quality of service. We demonstrate our idea by appropriately extending a QoS-sensitive version of the AODV routing protocol, and presenting a simulation-based evaluation. Simulation results show the effectiveness and efficiency of our idea.

The interconnection of piconets in Bluetooth networking has received considerable attention. Whilst a variety of scatternet formation protocols have been proposed, a persistent problem is the comparison of protocol performance, and the quality of Bluetooth network produced. Knowledge of best possible networks is important because this gives a concrete benchmark against which decentralized protocols can be compared. We introduce a new meta-heuristic framework for optimal scatternet formation that operates in a centralised manner. Given device locations, this is capable of exploring the search space of all possible scatternets to find high performance networks, taking into account multiple and tenuous objectives.