Handling Membership Dynamicity in Service Composition for Ubiquitous Computing

In ubiquitous computing, as more and more devices are introduced into the environment, new applications are made possible that exploit device capabilities in new ways. Currently, however, there is a mismatch between the effort involved in implementing these applications and the benefit they provide. A proposed solution is to use a service oriented architecture and implement applications as composite services. As long as the set of services that constitute the composite is static, traditional techniques can be used to specify the composite. In this paper we show how the PalCom service composition language can be extended to support service composites with dynamic membership and present a decentralized implementation. Preliminary user studies indicate that the extensions are easily understandable and simulations of application scenarios show that the performance of the implementation is appropriate for ubiquitous computing applications.