Daniel Hardy

Optics, the key to the ultra high-speed networks

Optical technologies are of prime importance in the context of ever increasing bit rates brought about by the introduction of digital techniques into telecommunications networks. They are the basis of the accelerating speed of information flow through the networks, with capacities now measurable in terms of Terabits per second and with Petabits per second (1015!) in prospect. The first part of this chapter deals with the elements that make up optical links, i.e. the fibre itself and the associated functions and devices for transmission, including optical and optoelectronic components. The implementation of optics in the networks is then presented, with an examination of multiplexing and Synchronous Digital Hierarchy (SDH), followed by transmission systems, including cables and their different specifications in terms of their usage (terrestrial long-haul transmission, submarine systems, access networks and user installations).

Radio access: the key to global mobility

‘Mobiles’ have invaded the planet over the last few years, and the phenomenon that has so influenced telephony is now, with the advent of the new UMTS generation, spreading to other types of service, promising higher bit rates and almost limitless access facilities.

A fibre-optic synchronous multiservice communications network

Today, the core of any large telecommunications network is a fibre-optic transmission system combined with SDH multiplexing techniques. This chapter introduces the various elements that make up the structure of such networks and goes on to consider architectures of the ring type. There follows a description of how networks are managed using the SDH facilities available, and new developments in transmission network equipment due to progress in optics are also discussed.

Towards the new generation networks

This final chapter attempts to give an overall picture of the various actors and their involvement in the changing networks, highlighting the concept that NGN globalization is the meeting point for a multitude of separate but converging approaches. The various scenarios possible will depend upon operator status (incumbent operator, new entrant or well-established competitor), industrial offer and initial implementation.

The evolution of the telecommunications market

This chapter is about the networks — which services to offer on them, which technologies to use on them, using which equipment and within which kind of international framework of coordination; the scope here is vast, and a wide perspective will be taken. Consequently, the explanations, at this level at least, will avoid technical detail and prioritize an understanding of uses and contexts.

The rise of digitization

This chapter introduces the various solutions which have been or are being implemented for the digitization of: speech, from the original PCM of the telephone networks to solutions adopted by the mobile networks (GSM, etc.); music, with the various versions used since the appearance of the compact disk, such as ‘MPEG layer 3’, better known as MP3; pictures, still and moving, either for interpersonal communication (videoconferences, videophony) or for broadcasting on traditional networks (cable, satellite, radio) and through packet communication networks with video streaming.

The new network economy

This chapter examines the impacts of the great changes in various economic aspects of the telecommunications world since the era of the monopolies. The analysis will in turn cover fixed telephony and its evolution under the effects of competition, the profound changes brought about by the development of high-speed packet networks and the spread of mobile telephony. In conformity with the subject of this book, emphasis will be given to the costs of the networks and to the distribution of these costs in terms of investment and operating expenses relative to the parts of the network being discussed. Particular attention will be paid to certain changes, such as the erosion of traffic routing costs in contrast to access costs and the repercussions of this phenomenon in the field of pricing.

The 64 kbps switched digital network

The switched telephone networks (PSTN) today enjoy the benefits of fully mature techniques that have been deployed now for many years. These techniques are essentially the digital technologies used for transmission and switching which have led to ISDN and Information Technologies (IT), associated with the concepts of the Intelligent Network, for controlling network resources and services. The first part of this chapter deals with the main architectural elements of PSTN/ISDN and the services offered.

Customer premises equipment and private networks

The privileged sector for the introduction of new services to the hitherto separate domains of telephony and data has generally been that of business telecommunications. This chapter describes in turn the recent changes in both of these domains, examines several particular cases of business telecommunication systems and discusses various solutions for setting up corporate networks. It also shows how convergence towards high bit rate and packet mode (IP) is resulting in telephone and data networks merging into multimedia corporate networks.

NGN: Defining a reference architecture

The main lines of NGN presented in the previous chapters may be widely agreed upon, but their implementation implies a number of changes in the traditions of the telephony-data-audiovisual world as well as that of fixed-mobile technology, all of which are expected to converge. It is, therefore, hardly surprising that no detailed solutions, from specifications to products, have yet been determined.