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Purpose -The purpose of this paper is to propose a novel quality of service (QoS)-aware service composition approach, called SEQOIA, capable of defining at run-time a service composition plan meeting both functional and non-functional constraints and optimizing the overall quality of service. Design/methodology/approach -SEQOIA is a semantic-driven QoS-aware dynamic composition approach leveraging on an integer linear programming technique (ILP). It exploits the expressiveness of an ontology-based service profile model handling structural and semantic properties of service descriptions. It represents the service composition problem as a set of functional and non-functional constraints and an objective function. Findings -The authors developed a proof of concept implementing SEQOIA, as well as an alternative composition solution based on state-of-the-art AI planning and ILP techniques. Results of testing activities show that SEQOIA performs better than the alternative solution over a limited set of candidate services. This behaviour was expected, as SEQOIA guarantees to find the service composition providing the optimal QoS value, while the alternative approach does not provide this guarantee, as it handles separately the specification of the functional service composition flow and the QoS-based service selection step. Originality/value -SEQOIA leverages on semantic annotations in order to make service composition feasible by coping with syntactic and structural differences typically existing across different, even similar, service implementations. To ease the adoption of SEQOIA in real enterprise scenarios, the authors chose to leverage on an XML-based message model of services interfaces (including but not strictly requiring the use of WSDL).

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Significant research efforts for the convergence of Web and Telecommunication services have been recently spent by research and industry stakeholders. The IETF and W3C are cooperating in specifying how web browsers should evolve to natively support communication services. In this perspective, devising novel mechanisms for signaling message exchange and possible interworking between Web-and SIP-based systems is a hot topic of research. Indeed, discussions are still ongoing on how differences between REpresentational State Transfer (REST) and Session Initiation Protocol (SIP) models should be coped with. This issue is made more difficult by the lack of rigorous modeling of RESTful systems. In this paper we propose a rigorous approach for design and implementation of REST communication services (e.g., a call service) which leverages formal verification techniques, while allowing to meet a specific performance requirement (i.e., maximum call setup delay). First, we formalize the call resource behavior through a Finite State Machine representation by modeling and simulating service expected behavior

Current research trends within a Next Generation Networks (NGN) are investigating the benefits and feasibility of developing integrated services in order to converge the Telco and Web worlds. These trends responds to the need to integrate features offered by heterogeneous subjects to provide new innovative value added services to end users on any device equipped with a web browser. This PhD work focuses on the study of service description models and mechanisms that facilitate and automate the interoperation and composition of heterogeneous services (Web and Telecom) within a NGN. The objectives of this research work are: first, creating a model for abstract and concrete service interface specifications for each service type and interaction model, second, defining a service creation environment (SCE) using a orchestration language to compose heterogeneous services, and third, developing a convergent platform for the orchestration and composition of heterogeneous services from different domains environments.