Harmonised Internet and PSTN service provisioning

Abstract

The current situation of telecommunications is characterised by the presence of multiple networks, each providing its own services. The original idea of a fully integrated network, which was originally introduced with ISDN and further propelled by the B-ISDN concept, seems unlikely to be realised at a complete extent. However, unification needs between different networks are present, an example being voice/data integration. Bringing together the characteristics of different networks creates a huge potential for new services, which can take advantage of strong points of individual networks in order to optimise specific service parameters. However, although network integration at transport technologies may be an idealistic assumption, the management of services traversing different networks cannot be done without considering the accurate definition of a unified service framework, taking care of harmonising, from a service designer's viewpoint, differences existing at network transport layers. In other words, if transport integration cannot be achieved, integration at service design and service management level must be pursued in order to cope with emerging and future services. Mobile Agent Technology (MAT) based on Distributed Object Technology (DOT) represents a key issue in defining methodologies and framework for a unified service environment encompassing different networks. These technologies, being largely independent from the underlying network, provide the means to build and manage services in a heterogeneous environment. Furthermore, they allow an easy deployment of new components on network systems, which is a key requirement in facing the problem of providing services in a fast and efficient way in a rapidly changing environment. This paper discusses a DOT/MAT based approach to the problem of creating and managing services in a heterogeneous network environment.

Introduction

Fast provisioning of new services to end users has rapidly become the key issue in the modern telecommunications environment, often being the most important element determining the success of operators and manufacturers considering both fixed and mobile network scenarios. Network convergence is taking place at many levels. From the telephony viewpoint, the current trend is to provide common services available in both wired and wireless domains. In addition, the emerging issue of voice/data integration also provides a framework for potential new and appealing services which can be offered to both telephony (fixed and mobile) and Internet users. In this context the Intelligent Network (IN) provides a key concept, since it represents today the globally accepted service platform for integrated service creation and provision [8]. This convergence calls for a unified handling of services, involving fixed and mobile telephony users as well as Internet ones, considering the complete service lifecycle (creation, deployment, management and runtime provisioning). Furthermore, the IN architecture can benefit from advances in software technologies, providing for a more distributed IN service provisioning environment [1], [8].

Considering IN evolution in terms of technological impact from both the convergence of Information Technology and Telecommunications (ICT, Information and Communication Technology) and the emerging trend of voice/data integration, the main target of this paper is the definition of an advanced network and service architecture for uniform and efficient creation, management, deployment and runtime provisioning of integrated cross-network services. This means that state-of-the-art software technologies, particularly Distributed Object Technology (DOT) and Mobile Agent Technology (MAT), are adopted as complementary basis, enabling interoperability and reusability of distributed service components and the dynamic distribution and extensibility of components (see Fig. 1).

The paper discusses an advanced, IN-based integrated PSTN/Internet environment on top of which cross-network services are designed and deployed in the network in a fast and cost-effective way. These services are derived from the integration between distinct network capabilities, like the ones offered by PSTN and the Internet, seen as a unified framework for service design, management, deployment and runtime provisioning. An important example is the family of services based on Voice over IP (VoIP) which have to be integrated with PSTN solutions [6].

The distributed IN considered in this paper takes into account the emerging evolution of centralised IN solutions (i.e. few centralised Service Control Points-SCPs are controlling a multiplicity of Service Switching Points-SSPs) towards distributed IN architectures based on widespread Service Nodes. Therefore, a distributed IN architecture, based on Distributed Object and Mobile Agent Technologies (DOT/MAT) is in the focus of the paper. In this context active network nodes, playing the role of combined SSPs/SCPs (Ss and CPs, Service Switching and Control Points) and of Internet Service Node (ISN) can be dynamically programmed according to time-varying needs by means of compact and extendable service objects. Activities carried out during European research programmes, as ACTS and ESPRIT, have shown that agent technology based on DOT has the potential to build flexible networks. However, a common framework and methodologies for a DOT/MAT-based service chain, including service creation aspects, is a target still to be achieved [2], [3], [4], [11].

Section 2 describes the need for a unified environment handling services in a transparent way across network boundaries. In Section 3 the reference network scenario is depicted. 4 PSTN architecture evolution, 5 Internet architecture evolution, respectively, report the authors’ views about PSTN and Internet architecture evolution. In Section 5, service creation and management aspects are discussed.