The Esperanto Broker: a Communication Platform for Nomadic Computing Systems

There is an increasing demand of middleware platforms which make easier the development of mobile computing applications. Due to the inherent limitations of mobile environments, these platforms have to address two fundamental issues: i) device movements and limitation of wireless networks could cause failures in communication, forcing users to experience short periods of service unavailability, and ii) the ever faster service development and deployment. This paper proposes the Esperanto Broker, a communication platform which addresses mobility issues via an integrated approach, i.e. both at data-link, network and middleware levels. As for the programming interface, the Esperanto Broker provides an object-oriented abstraction of four different interaction paradigms, i.e. request/response, oneway, solicit/response, and notify. Using the platform, developers can model applications as a set of objects that are distributed over mobile devices and interact via remote method invocations. In order to achieve decoupling interactions among mobile devices, a distributed tuple-space infrastructure has been adopted. The paper focuses on the EB design model, essential aspects of the implementation, and performance evaluations of the implemented prototype.