Application of the Java Message Service in mobile monitoring environments

Distributed systems and in particular sensor networks are in need of efficient asynchronous communication, message security and integrity, and scalability. These points are especially important in mobile environments where mobile remote sensors are connected to a control center only via intermittent communication, e.g. via satellite link. We present an approach that is able to deal with the issues that arise in such scenarios. In particular we focus on providing a solution that allows for flexible and efficient cargo monitoring on trains. The Java Message Service presents a flexible transport layer for asynchronous communication that provides a transparent store-and-forward queue mechanism for entities that need to be connected to each other. Previously JMS was primarily used in always-connected high-bandwidth enterprise communication systems. We present the advantages of using JMS in a mobile bandwidth limited and intermittently connected monitoring environment and provide a working implementation called the Transportation Security SensorNet (TSSN). It makes use of an implementation of JMS called ActiveMQ that is used here to enable monitoring of cargo in motion along trusted corridors. Results obtained from experiments and a field trial show that using JMS provides not just a practical alternative to often custom binary communication layers but a better and more flexible approach. One reason for this is transparency. Applications on both communication ends only need to implement JMS connectors while the remaining functionality is provided by the JMS implementation. Another benefit arises from the exchangeability of JMS implementations. In utilizing JMS we present a new and flexible approach to deal with challenges such as intermittent and low-bandwidth communication in mobile monitoring environments.