| Abstract: |
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. Typically, there will be traffic within and across radio networks, as well as back to a central infrastructure (e.g., a police command post) when a reach-back link is available. This implies that using Publish/Subscribe is advantageous in order to reduce network traffic, and that store-and-forward capabilities are required to handle the instability of radio networks. At the same time, it is desirable to use commercial software based on standards as far as possible, in order to reduce cost and development time, and to ease interconnection of systems from different organizations. We therefore propose using SOA based on Web services in such scenarios. Indeed, Web services are targeted at stable, high-speed networks, but our work shows that such usage is feasible. In this paper, we add Publish/Subscribe functionality to standard, unmodified Web services through the use of our prototype middleware solution called the Delay and Disruption Tolerant SOAP Proxy (DSProxy). In addition to the ability to make Web services delay and disruption tolerant, the DSProxy enables SOAs in scenarios as described above. The DSProxy has been tested in field trials, with promising results. |