The Future Internet is becoming a reality, providing a large-scale computing environments where a virtually infinite number of available services can be composed so to fit users’ needs. Modern service-oriented applications will be more and more often built by reusing and assembling distributed services. A key enabler for this vision is then the ability to automatically compose and dynamically c...

Telecom services are usually described from an applicative perspective. Service providers should yet describe formally what their services do for their users, in order to adapt them to user's needs and to compose them. We propose here a framework to describe communication services from a usage perspective, by describing formally the actions of the service users and of the service provider. This...

Services are loosely coupled interacting software components. Since two or more services are usually composed to one software system, the behavior of an implemented service should not differ to its specification. Therefore we propose an approach to test, if the implementation contains unspecified behavior. Due to the interacting nature of services this is a

Providing composed Web Services based on the QoS requirements of clients is still an urgent problem to be solved. In this paper, we try to solve this problem. Firstly, we enhanced the current WSDL to describe the QoS of services, and then gave a way to choose the proper pre-exist services based on their QoS.

The DARPA Agent Markup Language ontology for Services (DAML-S) enables the description of Web-based services, such that they can be discovered, accessed and composed dynamically by intelligent software agents and other Web services, thereby facilitating the coordination between distributed, heterogeneous systems on the Web. We propose a formalised syntax and an initial reference semantics for D...

The gain of the paper is to introduce and to discuss a formal specification of computer system’s Service Level Agreement (SLA) and its translation into structure of complex services (composed of atomic services) delivering required functionalities and non-functionalities in distributed environment. The SLA is composed of two parts specifying quantitative and qualitative requirements. The former...

Security is an important concern for service based systems, i.e., systems that are composed of autonomous and distributed software services. This is because the overall security of such systems depends on the security of the individual services they deploy and, hence, it is difficult to assess especially in cases where the latter services must be discovered and composed dynamically. This paper ...

This paper presents a survey of relevant transactional and recovery issues for the development of processes that are composed of web services in a service-oriented architecture (SOA). A process in an SOA is not a traditional ACID transaction due to the loosely-coupled, autonomous, and heterogeneous nature of the execution environment. As a result, processes that are composed of web services can...

Web services are usually selected and composed based on their reputation. In general, the reputation of a web service is computed using the feedback provided by the user. However, the users’ feedback bears many problems, including a low incentive for providing ratings and a bias towards positive or negative ratings. In this paper, we propose a method that overcomes the dependency on users’ feed...

Users’ needs are the driver of the next generation of telecom services. Founding the services on users’ needs requires that various services cooperate together to meet specific needs. As a consequence, services should no more be developed as “silo” but with composable service enablers. This enabler paradigm raises the issues of the identification of the enablers and of the consistency of a serv...