Public Telecommunications Networks Research Articles

Designing an ATM switch for extreme reliability

Lucent Technologies PacketStar ATM Core Switch is designed to deliver the high reliability required in public telecommunications networks. It achieves this reliability through use of a variety of strategies including duplication of hardware and software components, isolation of groups of components to minimize the effect of problems, fault recovery hierarchies, and others. As a result, cell loss is very minimal during problems, and permanent virtual circuits are unaffected even if the main switch control system goes down.

Bringing java to TMN

The Telecommunications Management Network (TMN) ITU, ISO, and NMF international standards define and support a network architecture for the management of public telecommunication networks. These standards address the TMN architecture, interoperability, services and protocols, general information modeling, a set of specific system management information functions and models, and recently a set of C++ interfaces to these components collectively called the NMF TMN C++ APIs. In addition, many vendor platforms and tools are available in support of these standards. Java is a programming language and virtual machine that has recently received significant attention and momentum. It is natural, therefore, to consider how best to use Java in a TMN. Although few of the contributions and promises of Java are new, Java has taken the best of breed programming language technologies to truly improve on issues of portability and productivity. This has been further enhanced by a concise and portable definition of Java's virtual machine. In this paper we suggest a pragmatic approach to apply Java in TMN. This approach uses Java to strengthen and enhance the TMN state-of-the-art. Java is applied to areas for which the state-of-the-art of TMN is lacking. In doing so, we emphasis Java's strengths while maintaining interoperability with already deployed technologies. Our approach is in contrast to more radical approaches which suggest widespread deployment of Java virtual machines throughout the core TMN infrastructure and telecommunications devices.

Strategic Networked Information Technology Applications: Empirical Results of Competitive Behavior

Competitive responses to a firm's strategic use of networked information technology (IT) vary according to the characteristics of the firm's environment and the ways in which it uses the technology. Innovative service applications appear to have the greatest potential for sustaining a competitive advantage, due to the difficulty that competitors have in responding to these applications. Internal process innovations also appear to have the potential for sustaining a competitive advantage. Product innovations appearing in industries that are not traditionally information intensive are also able to sustain a competitive advantage, possibly due to the fact that competitors are less familiar with ways in which to use the technology. Finally, public telecommunications networks can be used successfully, and their use does not necessarily incite responses from competitors. Copyright 1998 by Oxford University Press.

MoU success stories: interoperability in telecommunications within a competitive, multiprovider, multicultural environment

Early elaboration and adoption of standards is an important prerequisite for interoperability of telecommunication networks, services and applications. Recognised worldwide and regional standardisation organisations, as well as a fast growing number of fora, are working towards this objective. But even more important are the mechanisms, by which the users—that means those, who might be the customers of standardised products—become convinced and decide to invest in those products, which allow seamless interconnection of networks, proper interworking of services and terminals and interoperability of applications. In Europe, where in parallel with the ongoing liberalisation of the telecommunications market, traditional regulatory instruments like public type approval requirements have become outdated, public network operators have developed a successful instrument for the coordinated introduction of networks and services: the so-called memoranda of understanding (MoUs). Most prominent examples for such MoUs are the memorandum of understanding on the development and coordinated implementation of a second generation mobile communication system—today well-known under the shortname GSM-MoU—and the memorandum of understanding for the coordinated introduction of ISDN. The main advantages and results of those MoUs are outlined in this paper. Based on these positive experiences—and of course taking into account the changing regulatory environment in the European Union and its member states, as well as the globalisation and convergence of the telecommunication and information processing market—telecommunications operators in ETNO (European Telecommunications Public Network Operators' Association) have now started the drafting of a new memorandum of understanding on an interoperability platform for broadband telecommunications services, based on asynchronous transfer mode (ATM)-technology (ATM-MoU), which is envisaged to be open for signature by any organisation lawfully able to provide public telecommunications networks and/or services from early 1998.

Pursuing the Holy Grail

This article shows that media convergence has always been a historical possibility but was foreclosed by private industry and/or governments intent on preventing cross-media combinations. In contrast, the current push to bring about information highways in Britain and Canada promotes rather than prevents media reconvergence. Given the uncertainties surrounding new media, three potential evolutionary paths are suggested: the emergence of `information suburbs' in contrast to the idealistic connotations associated with information societies; new media as adjuncts of `old media'; or a strategy that seeks to expand the range of universal service and media freedoms for the many rather than the few and which uses ISDN as the cornerstone of the fixed public telecommunications network.

A packet routing method based on game theory

The size of public telecommunication networks and computer networks is becoming quite large, and various new control features and services are being offered so that a large amount of control is needed and enormous amounts of data must be handled. Thus there is a need to utilize the limited network resources efficiently and effectively. In this paper, we propose a distributed control method based on game theory, in which the performance of the whole network is levelled without regard to the quality of communication, and each element of the network has a basically independent function. It is shown by computer simulation that the packet loss rate caused by timeout can be decreased. © 1998 Scripta Technica. Electron Comm Jpn Pt 1, 81(8): 89–96, 1998

A packet routing method based on game theory

The size of public telecommunication networks and computer networks is becoming quite large, and various new control features and services are being offered so that a large amount of control is needed and enormous amounts of data must be handled. Thus there is a need to utilize the limited network resources efficiently and effectively. In this paper, we propose a distributed control method based on game theory, in which the performance of the whole network is levelled without regard to the quality of communication, and each element of the network has a basically independent function. It is shown by computer simulation that the packet loss rate caused by timeout can be decreased. © 1998 Scripta Technica. Electron Comm Jpn Pt 1, 81(8): 89–96, 1998

Securing payments through effective authentication: Evaluating trusted third party proposals for a trust hierarchy in the UK

With the exponential growth in the use of the Internet in the past three or four years and its metamorphosis from a military and academic network to a business tool and recreational arena, the business and user communities' attention has focused increasingly on its inherent (or perceived) weaknesses and the manner in which they can be reduced or eliminated. At the forefront of current thinking in terms of security is the use of cryptography and cryptographic techniques which can be used to ensure the confidentiality of communications, the integrity of messages and data packets and to confirm the identity of the communicating parties. Until the early 1970s, the science of cryptography was primarily of interest to governments (so that secure communications could be used by the military and intelligence services) and academic mathematicians. With the increase in the number of computer networks and uses to which they were put, security, and hence cryptographic systems, became of increasing importance to users of the systems especially in the financial services sector. However, governments (and the intelligence agencies in particular) guarded jealously the technologies in question and digital cryptographic systems were included in the list of controlled technologies produced by the Coordinating Committee for Multilateral Exports Control — COCOM1. The approach taken by COCOM, until it was disbanded in March 1994, influences to this day the manner in which encryption technology is controlled by the United Kingdom and other European Union States. The purpose of this paper is to look at the UK Government's various proposals in relation to encryption on the public telecommunications network; it also looks at certain UK developments in relation to the use of encryption; and compares the developments in the UK with those in the EU and with some of the attitudes to the use of encryption being taken by international organizations such as the Organization for Economic Cooperation and Development (OECD) and the International Chamber of Commerce.

Otporne funkcionalne telekomunikacione mreže

Some users of telecommunications networks, army forces for example, have requirements which differ from the requirements for public telecommunications networks (PTNs). The difference between PTNs and special requirements networks is analyzed and, for the time being, PTNs cannot fulfill these special requirements. One of the most important of them is resistance of which basic components are network security, reliability and mobility. Networks with greater resistance form a subclass named the resisting functional telecommunications networks for which design and system architectures are proposed in the paper.

Standards, trade and competition in the emerging global information infrastructure environment

Decentralized construction of the Global Information Infrastructure (GII) is substituting market-driven, ‘de facto’ standards and voluntary agreements on standards for technical compatibility, in place of the engineering decisions once made by public (and quasi-public) telecommunications network operators. Due to strategic economic behaviours on the part of private businesses and national governments, the goal of a fully interoperable GII remains elusive. The Internet does not offer an entirely credible alternative model, as the standards that have facilitated its explosive growth also are contributing to serious congestion problems, and the solutions proposed point to the Internet's re-integration into the public switched telecommunications network. Technical standards will shape the GII's implications for international trade and competition, and thus raise important, but inadequately recognized issues for regulation, competition and trade policy.

Réseaux de Télécommunications, Domotique et Téléaction

. Renewed interest in home integrated systems primarily concerns applications for security, remote control, energy saving, domestic communication networks, etc. . To meet emerging requirements for applications in these areas, manufacturers frequently adopt advanced technology solutions involving digital electronics, radio transmission, and integrated remote control capabilities operated via the public telecommunications network. . For remote control functions, alternatives to the basic telephone system include X25 networks and multiservice networks such as Transveil and ISDN.

Architecture and performance of HIPPI-ATM-SONET terminal adapters

The flexibility of the asynchronous transfer mode (ATM) technique to integrate diverse traffic using a single network platform, and the scalability of the synchronous optical network (SONET) to support various transmission speeds up to gigabit per second ranges, have contributed to the adoption of these standards in the future public telecommunications network. Presently, the networking of supercomputers and high performance workstations is widely based on the high performance parallel interface (HIPPI) standard. A number of efforts to allow the access of HIPPI networks to the public ATM/SONET network has resulted in different experimental Gigabit Testbeds such as CASA and Nectar. To provide the access of HIPPI-based local area networks (HIPPI-LAN) to the ATM/SONET network, HIPPI/ATM/SONET (HAS) terminal adapters could be deployed in instances where the cost of evolving the HIPPI network into a full ATM/SONET-based network is higher than that of a HAS interface. This article presents the architecture and performance of a 2.5 Gb/s HAS experimental prototype, which is a key component of the Nectar Gigabit Testbed. It identifies HAS implementation issues and presents possible solutions that can be extended to the implementation of future HAS devices. The HAS architecture is presented, as well as a discussion on flow control implications due to terminating the HIPPI protocol. The HAS performance is then shown through theoretical modeling and measured results.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Satellites and developing countries

Most developing countries use satellite technology for international rather than for domestic communication. In the future, there should be substantially increased domestic and regional use of satellite technology. The potential exists in this application for enormous increases in traffic, and the impact on developing countries' economies will be the greatest. In addition to the international links, several developing countries also employed INTELSAT capacity to establish domestic public telecommunication networks. Generally, these early domestic networks were set up in special situations where difficult terrain, climatic conditions, or territories separated by large bodies of water, made conventional telecommunications impossible. Subsequently, a number of these developing countries, including India, Indonesia, Brazil, and Mexico, launched their own satellites to connect these networks. >

Public network integrity—avoiding a crisis in trust

Public telecommunications networks have historically been designed with high levels of integrity in mind. Network architects have recognized that public communications facilities play a critical role in society and that a disruption in service could cause severe economic dislocation or even the loss of life. Given this sensitivity, how could the recent series of massive network failures occur? What went wrong with our thinking? What should we change in the future to prevent the recurrence of such failures and thereby avoid a possible crisis in the public's trust of our stewardship? The paper addresses these questions and offers a set of recommendations based on new network integrity measures and design objectives.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Integrity of public telecommunications networks

Provides an overview of the special issue of the IEEE Journal of Communications, Volume 12, Number 1 (January 1994) which addresses open questions in network integrity, reliability and survivability. Current progress in this area is discussed. The questions addressed include user survivability perspectives on standards, planning, and deployment; the analysis and quantification of network disasters; survivable and fault-tolerant network architectures and associated economic analyses; and techniques to handle network restoration as a result of physical damage or failures in software and control systems. Special interests are devoted to the survivability of broadband networks employing the new transport/switching techniques based on the synchronous optical network (SONET) and asynchronous transfer mode (ATM) standards due to their emerging role in future B-ISDN. Network integrity due to failures of common channel signaling (CCS) systems is also very critical. The present special issue includes 22 papers and is organized into the following sections: user perspectives and planning, software quality and reliability, network survivability characterization and standards, network restoration for SONET networks, network restoration for ATM networks, traffic effect and performance enhancement for computer networks, and survivable network design methods. Network restoration methods for SONET, ATM, and computer networks correspond to those for the physical layer (SONET), ATM layer, and the network layer, defined in the CCITT broadband ISDN layer structure.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Network planning methodology and practice in China

The methods used in local network planning for the public telecommunications network in China are discussed. Network modeling, computer simulation, and planning software used in the planning process are described. A computer-aided planning tool for local telephone networks (CAPTLN), composed of three software modules that provide traffic forecasting, network optimization, and network economic analysis for the local network of the public switched telephone network (PSTN), is also discussed. Other tools are similarly used for all other parts of the PSTN network, such as international access, toll switching and trunking, signaling and synchronization. >

B-ISDN and the OSI protocol reference model

The evolution of public telecommunication networks toward broadband integrated services digital networks (B-ISDNs) is presented. The asynchronous transfer mode (ATM), which supports B-ISDNs, and the B-ISDN protocol reference model are discussed. It is shown that the service offered by the ATM layer in the B-ISDN protocol reference model is equivalent to the service offered by the OSI physical layer. It is also shown that the service offered by the ATM adaptation layer (AAL) type 3/4 is similar to an OSI data link service. The emergence of the metropolitan area network (MAN) standard as an intermediate support for broadband services and the similarities between the DQDB MAC and the AAL type 3/4 in its connectionless mode are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A layered approach to network management control

Public telecommunications networks have many supporting operations systems to provide network management functions and operational support. These systems must be coordinated to provide a highly reliable network service and to make best use of network resources. With increasing automation of network control, these systems must evolve to provide total network support. One organizing principle for this evolution is the definition of control layers at which individual control functions are exercised. We describe a proposal for layered control, with particular emphasis on the role of network traffic management. Layering will be a significant study item for the next extensions to CCITT's Telecommunications Management Network (TMN) recommendations.

Public networks-dependable?

The dependability of public networks is analyzed. The growing reliance of all segments of society on public telecommunications networks is described. The challenge in maintaining traditional dependability levels in the face of new network constructs having less inherent reliability is discussed. A new measurement for network quality and standards for public network dependability are proposed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

International standardization of BISDN

The status and technical characteristics of broadband ISDN (BISDN) as they are currently being defined by the International Consultative Committee for Telephone and Telegraph (CCITT) are outlined. Four main aspects of BISDN are considered: the services supported by BISDN, including their impact on end-to-end network requirements; the different protocol layers necessary to build a BISDN capable of supporting the above-mentioned services; the nature of the user-network interface (UNI), including the features necessary to support different customer premises' configurations; and the network control aspects necessary to allow the protocols and UNI to support BISDN services. The new service opportunities that BISDN will bring to public telecommunications networks are identified.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>