Books

Recommended reference manual

Open Systems, by Gary J Nutt. Prentice-HalL Englewood Cliffs, N J, 1992, pp. 292, £31.95

Today's computer systems, generally heterogeneous due to the multivendor environment, are supposed to meet the needs of their users by providing full inter- connectivity among all parts of the system (PCs, workstations, main- frames, and the communication network), and by facilitating multimedia representations (data, voice, images). Further, such systems should be available to the end-user organization at the most competitive price. The open systems approach is simply a reaction to all the demands mentioned above: an open system is specifically designed to accommodate components from various vendors.

In this book the author introduces the wide variety of topics that encompass open systems. He provides a view of open system from three perspectives: portability, interoperability, and integration, considering each of them as a fundamental cornerstone. At the same time, he takes into account two main groups for which such information is essential: those who build the open systems, and those why buy them. The author is aware, though, of the complexity concerning all aspects of open systems, and he has therefore targetted the book as an introductory test.

The first chapter describes the main principals of open systems, showing the motivations of their origin and their technical foundation. Chapter 2 explains the first essential requirement of open systems: portability. It describes its diverse aspects such as layered

architectures, introducing a platform model, global software portability issues (including internationalization), the relevance of languages that support inter- faces (including object-oriented languages), and it provides a description of the X/Open architecture. The third chapter, 'Computer architecture', deals with hardware fundamentals mainly. The following chapter, 'Operating systems', describes the principles of operating systems, mainly Unix. Chapter 5 concludes the section on portability by describing portable tool platforms.

The next two chapters address open systems from the inter- operability viewpoint. Chapter 6 describes basic network aspects, while chapter 7 introduces the features ofinteroperability in terms of more abstract distributed systems. The final two chapters focus on applications: chapter 8 surveys integration issues, discussing presentation, behaviour and functional integration: chapter 9 summarizes the design of a

complete open system for an office information system.

The whole book concludes with a broad bibliography and index. Unfortunately, the reader will not find a list of acronyms, nor definitions, where both of them would have been very useful.

As the material was derived from professional educational courses in commercial organizations (with a great number of figures, programs, and practical examples), it can be easily understood by practicing programmers and software managers. Besides describing the principles of open systems, the book serves as a reference manual for software managers, software professionals, designers, imple- reenters and students in relevant fields, because each chapter is followed by a list of recommended literature. As there are few books on the market dealing with open systems, offering such a breadth of topics and a depth of technical coverage, this can actually be recommended to a very broad spectrum of readers.

Rita Puzmanov~ Boleslavsk~

Czechoslovakia

Patchy amalgamation of reports Convergence Between Communica- tions Technologies, OECD Press, France, 1992. 147 pp

This book describes economical and political issues of the convergence of broadcasting and telecommunication facilities in North America and Western Europe. It consists of two case studies, the main goal being to make the results of the case studies widely available. It is intended for managers and government

employees concerned with broad- casting or telecommunications, focussing on economic or political issues.

It is written in an informal, easy- to-read style, and is augmented with several tables giving concrete numbers related to issues like cable TV, telephone and teletext evolution. Such information has proven very valuable for illustrating and motivating recent deployments in these areas, especially to a management-level audience.

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Books

A brief introduction motivates the contents; it is argued that a close understanding of the relation- ship and impact of the broadcasting and telecommunica- tions sector is required due to the rapid evolution in these fields.

The first case study focusses on North America, describing the current status of the broadcasting and telecommunications industry in Canada and the US. The structure of the main companies and their market shares are illustrated with detailed numbers. Then new technological deploy- ments (e.g. fibre optic channels, HDTV) and their competitive risks for participants in these markets are outlined. The discussion comes to some useful economic and strategic conclusions, but remains non- technical and is sometimes speculative. Finally, existing government regulations of both countries are described and compared - valuable information that would be hard to find elsewhere in this form. Moreover, general hints and policy conclusions of how to stimulate technological innovation in the field could be directly used by a telecommunica- tions manager. A set of notes and references conclude the first case

study; while some give useful hints, references to more technical material about the technologies involved would have been desirable.

The second case study about Europe is structured differently. First, the changing telecommunica- tions service industry is described (mainly focussing on increasing liberalization and technologies like ISDN). Important political background information is provided, e.g. about the RACE projects supporting technological progress, but readers interested in technical material will not find much information. The focus then moves to the evolution of the European audiovisual industry, especially concerning satellite broadcasting, VSAT services, and cable TV. Most interesting are the tables comparing important economic figures, divided by different European countries (with a special focus on the UK); readers can compare evolution in specific countries quickly and easily. However, as in the other sections, more technical background information and perhaps more examples would have been desirable.

The final conclusion concerning

future technological convergence is rather weak. On a more positive note, the appendices give a valuable survey of existing telecommunica- tions and broadcasting regulations in Europe on a country-by-country basis. This is very helpful for international comparison of specific regulation issues. An overall conclusion integrating the results of the two case studies, however, is not provided at all; interested readers would definitely expect such a summary. References for the European case study - as given for the American study - are also missing; unfortunately, this non-uniform approach underlines the fact that the book is more a concatenation of two reports rather than a comprehensive documenta- tion of the overall subject area.

In summary, the book may be useful for management personnel interested in basic numbers and high-level background information about telecommunication and broadcasting covergence. However, it cannot be recommended to readers seeking technical informa- tion, nor can it be used as a textbook for telecommunications classes.

Dr Alexander Schill University of Karlsruhe, Germany

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