Topic Discovery for Publish/Subscribe Web Services

Using the publish/subscribe paradigm for information exchange allows for loose coupling between information sources and consumers. It also reduces network usage because it ensures that information is only transmitted when there is new information available. This is particularly useful in mobile networks, where network capacity can be low. Subscription based information exchange is often built around the concept of topics, where a consumer subscribes to the topics it is interested in. Consumers then need to be able to find out which topics are available to subscribe to, and where to subscribe to them. When using Web services, the consumer uses a discovery mechanism to find information sources, but the current standards for service discovery do not support discovery based on topics. In this paper we extend the WS-Discovery standard with a topic matching rule, which enables consumers to search for Web services providing information about a given topic.