Semantic-Aware Service Quality Negotiation

Goal of Web service discovery is twofold: (i) to find Web services able to perform the functionalities required by a user, and (ii) to select, among the found Web services, which are the ones able to work in the way the user wants. Focusing on the second step, usually, a matchmaking algorithm takes place to verify if the quality offered by the Web service provider contains the quality requested by the user. Since quality costs, a further step, i.e., the negotiation, should be performed to identify which is the quality level that must be ensured at run-time. In order to automate the negotiation process as much as possible, users and providers need to have a common understanding about the meaning of quality dimensions and negotiation strategies. In this work, we join previous work on semantic-based quality definition model and negotiation process, to provide a framework enabling the automatic Web service negotiation. More specifically, OWL-Q, a semantic QoS-based WS description language, is extended with all the appropriate negotiation concepts and properties. Finally, by building on OWL-Q and rules, a small example is provided of how QoS negotiation can be assisted and get automated.