QoS-Aware Semantic Service Selection: An Optimization Problem

In order to select the best suited service among a set of discovered services, with respect to QoS parameters, a user have to state his or her preferences, so services can be ranked according to these QoS parameters. Current semantic Web services ontologies do not support the definition of QOS-aware user preferences, though there are some proposals that extend those ontologies to allow selection based on those preferences. However, their selection algorithms are very coupled with user preferences descriptions, which are defined without semantics or at a different semantic level than service functionality. In this work, we present a service selection framework that transforms user preferences into an optimization problem where the best service is selected. This framework is based on an ontology that conceptualizes these user preferences. Thus, we use a very expressive solution decoupled with the concrete selection technique by using XSL transformations, while describing QoS-aware user preferences at the same semantic level of functional preferences.