Enabling Publish/Subscribe with COTS Web Services across Heterogeneous Networks

In scenarios such as search-and-rescue operations, it may be required to transmit information across multiple, heterogeneous networks, often experiencing unreliable connections and limited bandwidths. Under such conditions, Publish/subscribe-based communication, combined with store-and-forward capabilities in the network nodes, greatly improves the ability to transmit information. At the same time, it is desirable to use commercial, standards-based software as much as possible, in order to reduce both cost and development time, and to ease the interconnection of systems from different organizations. In this paper, we present our prototype middleware solution called the Delay and Disruption Tolerant SOAP Proxy (DSProxy) which adds Publish/Subscribe functionality to standard, unmodified Web services. Together with its ability to make Web services delay and disruption tolerant, the DSProxy enables SOA based on Web services in scenarios as described above. The DSProxy has been tested in field trials, with promising results.