Service trading in mobile environments

One of the most important considerations for applications operating in a mobile environment is the ability to dynamically adjust to changing resource availability. With a dynamic resource location service as part of the infrastructure, mobile applications are able to re-bind to service providers as they move within the mobile environment and as available services change. As part of the ISO/IEC and ITU-T standardisation of the Reference Model for Open Distributed Processing (RM-ODP), a trading function has been identified. It is an important infrastructure service that allows clients to locate services using service types and associated parameters as selection criteria. In order to engineer reliable open object-based distributed systems, it is important to perform modelling and analysis as part of the design process. This paper introduces the reader to the concept of service trading and indicates how it may be utilised by applications in a mobile environment. In addition, coloured Petri nets are shown to be useful for the modelling and verification of distributed mobile applications