As the provision of services and the use of personal data expands, the need for services to explicitly detail what personal data a service handles and in which manner becomes paramount in order to achieve a fully transparent, ethical and personalized user experience. Services usually require access to sensitive information and may distribute this information to third parties. Service consumers need to be informed about the ways their data are used and about the actors involved in this process. Universal service descriptions that can be used to cover any business service are required to provide interoperability. In this paper, we describe our work on the privacy module for the Linked Unified Service Description Language (USDL). We expand the language by introducing a new module that allows the specification of privacy properties for business services. We have considered recent advances in data protection for its creation and provide a method, accompanied by a software tool, to examine the validity of privacy policy descriptions with Linked USDL Privacy module.

Nowadays, service trading over the Web is gaining momentum. In this highly dynamic scenario, both providers and consumers need to formalize their contractual and legal relationship, creating service level agreements. Although there exist some proposals that provide models to describe that relationship, they usually only cover technical aspects, not providing explicit semantics to the agreement terms. Furthermore, these models cannot be effectively shared on the Web, since they do not actually follow Web principles. These drawbacks hamper take-up and automatic analysis. In this article, we introduce Linked USDL Agreement, a semantic model to specify, manage and share service level agreement descriptions on the Web. This model is part of the Linked USDL family of ontologies that can describe not only technical but also business related aspects of services, incorporating Web principles. We validate our proposal by describing agreements in computational and non-computational scenarios, namely cloud computing and business process outsourcing services. Moreover, we evaluate the actual coverage and expressiveness of Linked USDL Agreement comparing it with existing models. In order to foster its adoption and effectively manage the service level agreement lifecycle, we present an implemented tool that supports creation, automatic analysis, and publication on the Web of agreement descriptions.

In this paper we present a theoretical analysis of graph-based service composition in terms of its dependency with service discovery. Driven by this analysis we define a composition framework by means of integration with fine-grained I/O service discovery that enables the generation of a graph-based composition which contains the set of services that are semantically relevant for an input-output request. The proposed framework also includes an optimal composition search algorithm to extract the best composition from the graph minimising the length and the number of services, and different graph optimisations to improve the scalability of the system. A practical implementation used for the empirical analysis is also provided. This analysis proves the scalability and flexibility of our proposal and provides insights on how integrated composition systems can be designed in order to achieve good performance in real scenarios for the web.

As the use of services available on the Web is becoming mainstream, contracts and legal aspects of the relationship between providers and consumers need to be formalized. However, current proposals to model service level agreements are mostly focused on technical aspects, do not explicitly provide semantics to agreement terms, and do not follow Web principles. These limitations prevent take-up, automatic processing, and effective sharing of agreements. Linked USDL Agreement is a Linked Data based semantic model to describe and share service agreements that extends Linked USDL, which offers a family of languages to describe various technical and business aspects of services. We followed a use case driven approach, evaluating the applicability of our proposal in a cloud computing scenario, and comparing its expressiveness with existing models. Finally, we show a concrete tool that helps to model and check the validity of agreements.

Nowadays, more and more distributed digital TV and TV-related resources are published on the Web, such as Electronic Personal TV Guide (EPG) data. To enable applications to access these resources easily, the TV resource data is commonly provided by Web service technologies. The huge variety of data related to the TV domain and the wide range of services that provide it, raises the need to have a broker to discover, select and orchestrate services to satisfy the runtime requirements of applications that invoke these services. The variety of data and heterogeneous nature of the service capabilities makes it a challenging domain for automated web-service discovery and composition. To overcome these issues, we propose a two-stage service annotation approach, which is resolved by integrating Linked Services and IRS-III semantic web services framework, to complete the lifecycle of service annotating, publishing, deploying, discovering, orchestration and dynamic invocation. This approach satisfies both developer's and application's requirements to use Semantic Web Services (SWS) technologies manually and automatically.