Session-Based Role Programming for the Design of Advanced Telephony Applications

International audienceStimulated by new protocols like SIP, telephony applications are rapidly evolving to o er and combine a variety of communications forms including presence status, instant messaging and videoconferencing. This situation changes and complicates significantly the programming of telephony applications that consist now of distributed entities involved into multiple heterogeneous, stateful and long-running interactions. This paper proposes an approach to support the development of SIP-based telephony applications based on general programming language. Our approach combines the concepts of Actor, Session and Role. Role is the part an actor takes in a session and we consider a session as a collaboration between roles. By using these concepts, we are able to break the complexity of SIP entities programming and provide flexibility for defi ning new ones. Our approach is implemented as a coding framework above JAIN-SIP

CIAO: A Component Model and its OSGi Framework for Dynamically Adaptable Telephony Applications

International audienceIn recent years, thanks to new IP protocols like SIP, telephony applications and services have evolved to other and combine a variety of communication forms including presence status, instant messaging and videoconference. As a result, advanced telephony applications now consist of distributed entities that are involved into multiple heterogeneous, stateful and long-running interactions (sessions). This evolution complicated significantly applications development and calls for more effective solutions. In this paper, we explore the adoption of components for addressing this issue, focusing specifically on the management and coordination of the numerous and various sessions occurring in such applications. The paper presents CIAO, a domain-specific and hierarchical component model for SIP applications. CIAO combines three kinds of component that are Actor, SessionPart and Role and manage them dynamically in accordance with real SIP sessions. By using these features, we are able to break the complexity of SIP entities and provide flexibility for their development. CIAO is implemented above OSGi to experiment the building of concrete SIP applications and enable their dynamic adaptation

Integration of Internet and Telecommunications- An Architecture for Hybrid Services

In this article, we propose an architecture for hybrid services, i.e., services that span many network technologies, such as the Public Switched Telephone Network (PSTN), cellular networks and networks based on the Internet Protocol (IP). These services will play an important role in the future because they leverage on the existing infrastructures, rather than requiring new and sophisticated mechanisms to be deployed. We explore a few issues related to hybrid services and propose a platform, as well as a set of components, to facilitate their creation and deployment. The existing infrastructure is only required to generate specific events when requests for hybrid services are detected. We present the design of a service layer, based on Java, that handles the treatment of these special requests. Our service layer is provided with a set of generic components realized according to the JavaBeans model. We illustrate the strength of our architecture by discussing two hybrid-service examples: a calendar service and a call forwarding service

Towards a Tool-based Development Methodology for Pervasive Computing Applications

Despite much progress, developing a pervasive computing application remains a challenge because of a lack of conceptual frameworks and supporting tools. This challenge involves coping with heterogeneous devices, overcoming the intricacies of distributed systems technologies, working out an architecture for the application, encoding it in a program, writing specific code to test the application, and finally deploying it. This paper presents a design language and a tool suite covering the development life-cycle of a pervasive computing application. The design language allows to define a taxonomy of area-specific building-blocks, abstracting over their heterogeneity. This language also includes a layer to define the architecture of an application, following an architectural pattern commonly used in the pervasive computing domain. Our underlying methodology assigns roles to the stakeholders, providing separation of concerns. Our tool suite includes a compiler that takes design artifacts written in our language as input and generates a programming framework that supports the subsequent development stages, namely implementation, testing, and deployment. Our methodology has been applied on a wide spectrum of areas. Based on these experiments, we assess our approach through three criteria: expressiveness, usability, and productivity

Standard Selection Modes in Dynamic, Complex Industries: Creating Hybrids between Market Selection and Negotiated Selection of Standards

Several sectors within Information and Communication Technology demonstrate a shift from purely market-based selection of standards or purely negotiated selection of standards to hybrid selection processes, where both market competition and negotiation play a role. Negotiated standard setting processes (such as those organised by the ITU) assure interoperability of technical components and services. Private firms, however, increasingly tend to undercut these collective actions. Their innovations jump-start new developments, but also create incompatibilities, lock-in effects, and pockets of market power. Internet telephony is an example, where firms, standard setting alliances, and political institutions create a hybrid market-based / negotiated standard setting environment. The paper explores the development of this hybrid networking environment. It posits propositions which are illustrated by means of case studies of the DVD and Internet telephony.industrial organization ;

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