Architecture and Governance for Communication Services E-Book

Emmanuel Bertin

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 350

Veröffentlichungsjahr: 2013

Beschreibung

Communication services are evolving at an unprecedented rate. No longer limited to interpersonal vocal communication, they now integrate functions such as address books, content sharing and messaging. The emergence of social networks – which may also include these features – is an important element of this transformation. Content services are becoming flagship services themselves, and are sometimes paired up with conversation services. The boundaries between different services are becoming less and less distinct. This book meets the need for a better understanding of communication services, and for a general framework of their description. A detailed overview on service architecture in the Telco, Web and IT worlds is presented, offering a roadmap with explanations on how to improve the architecture and governance of communication service architectures by exploiting the syntax and semantics that are common to different services is clearly outlined. This book also responds to recurring questions about service design, such as the functional scope of enablers or SOA (Service Oriented Architecture) services, the relevance of service composition to the user and collaboration between different services in a converged environment. Many concrete examples from telecoms service providers’ operations illustrate these concepts.

Leseprobe

Contents

Foreword

Introduction

Acknowledgements

Chapter 1: Describing Service Architectures

1.1. The telecommunications community

1.2. The Web community

1.3. The IT community

1.4. Summary

Chapter 2: Convergence of Service

2.1. Overview of communication services

2.2. Common developments of the service sector

2.3. Application to telecoms services

2.4. Summary

Chapter 3: Building an Architectural Framework for Telecom Services

3.1. A business reference view for telecom services

3.2. A functional reference view for telecom services

3.3. A technical reference view for telecom services

3.4. Summary

Chapter 4: Modeling and Case Study

4.1. The business reference view

4.2. Functional reference view

4.3. The technical reference view

4.4. Functional view of a service

4.5. The technical view of a service

4.6. The applicative view of a service

4.7. Summary

Chapter 5: Organizational and Software Applications

5.1. An aid for the construction of service offers

5.2. An aid for the rationalization of services

5.3. An aid for achieving service convergence

5.4. Summary

Conclusion

Appendix 1

Bibliography

List of Figures and Tables

Index

First published 2013 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUKwww.iste.co.uk

John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USAwww.wiley.com

© ISTE Ltd 2013

The rights of Emmanuel Bertin and Noël Crespi to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Control Number: 2012954576

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN: 978-1-84821-491-0

Foreword

This book constitutes a significant advance for architects in building communication services. The authors address the challenging issue of compiling together service concepts gathered from various communities, such as from Telco, the Web and information technology (IT) sectors, to present a clear method for designing service architectures using different perspectives: business, functional, technical and applications.

The book provides a very coherent flow. This allows the reader to obtain an in-depth knowledge on the topic when read sequentially, but at the same time each chapter is self-contained enough so that the reader can comprehend each one separately.

Its broad analysis of the communication service area, the technically sound treatment throughout, combined with a deliberately structured writing approach make this book suitable for various purposes. First, it establishes a solid survey for newcomers to communication services; those who wish to learn about existing architectures in different domains and communities. Second, it stands as a must-have reference for graduate and undergraduate courses that include service communication topics. Third, this book is a key tool for professionals who work in the area of communication services, as it will help them to better understand the concepts they are handling every day, and to define more precisely the functional and technical requirements of service architectures by formalizing them with a simple method. This book will be a valuable resource for network operators and service providers in their design and organization of telecommunication services.

Finally, the book merges perfectly the background of its authors and incorporates, on the one hand, the pedagogy that leads to very enjoyable reading and, on the other hand, the usefulness and timeliness of a relevant problem that is becoming a core issue for major players in the current Internet era.

Thomas Magedanz

Professor of the chair for Next Generation Networks at TU BerlinDirector of the Next Generation Network Infrastructures (NGNI)Competence Center at Fraunhofer Institute FOKUSGermanyFebruary 2013

Introduction

Communication service architectures have been the object of numerous studies. More recently, evolutions (revolutions) in technology, markets and usage have forced us to reconsider how we describe these architectures.

In effect, telecoms services are no longer the prerogative of operators. Service providers without a network make use of the universal network, the Internet, to provide their services, such as Skype, Google and YouTube. They do not rely on a network architecture to provide their services, but on technical architectures that come from the Web and information technology (IT) worlds. These service providers, who generally have a revenue model based on advertising, have greatly changed telecom services by giving a greater consideration of the user of a service rather than of the client of a network access offer.

Communication services hence are evolving rapidly. They are no longer limited to interpersonal vocal communication, but integrate functions such as email, address books and instant messaging. The emergence of social networks – which may also include these features – is another important element of this transformation. Content services are becoming flagship services, and prototypes allow them to be paired up with conversation services. As a way to best manage and profit from this abundance of services, some service providers are offering users the tools to combine different service features or even assemble services to respond to their specific needs. The boundaries between different services are becoming ever less defined. For example, contacts in an address book service can be used both when sending an email and when making a telephone call. Thus the user can access an environment where services are capable of interacting with each other.

Today, the idea of building a monolithic application containing all services is an illusion at least for reasons of technical feasibility of upgradability (for the introduction of new features). Service architectures are becoming more and more complex as they are composed of a multitude of interacting modules.

If the description of network architectures is relatively clear, being based on the results of decades of standardization, the description of communication service architectures is much less defined. Terms denoting a technical environment for the execution of informatics applications are often used, such as application server (AS) and service platform or service delivery platform (SDP), to indicate the service rendered, for example referring to telephone AS or presence AS. Moreover, telcos tend to standardize enablers – i.e. reusable applications in the frameworks of different services – to provide frequently used functions, without clarifying the construction methods of these enablers or distinguishing between the enablers that provide a service to users and those that provide a technical facility.

This book proposes a general framework to better describe communication service architectures. It aims both to formalize these architectures by using a syntax and a semantics that are common to different services, and to respond to recurring questions about service design, such as the identification of the functional coverage of enablers or service-oriented architecture (SOA) services, the relevance of service compositions to the user, and the communication between services in a converging environment.

We begin by analyzing the existing methods of describing service architectures in telecoms, Web and IT communities in Chapter 1. Next, we present an overview of communication services in Chapter 2. We discuss the changes in these communication services, matching them most generally with the service sector of the economy. This step leads us, in Chapter 3, to propose invariants for the formalization of communication service architectures across three views of reference: a business view, a functional view and a technical view. Chapter 4 deals with case studies, illustrating these different views and their implementation to describe service architectures. Finally, we finish with Chapter 5, where we highlight the added value of this method through examples of organizational and software applications.

Acknowledgements

The authors would like to extend their thanks to their colleagues who helped them in the writing of this book, in particular Angel Cuevas, Hervé Le Corre, Serge Fdida, Yvon Kermarrec, Luigi Lancieri, H. Shah Newaz, Rogier Noldus, Guy Pujolle, Jacques Simonin and Djamal Zeghlache.

The authors welcome comments and suggestions for changes that could be used for future editions of this book. Our email addresses are:

[email protected]@telecom-sudparis.eu

Chapter 1

Describing Service Architectures

This topic has already given rise to numerous works in the telecoms, Web and IT communities. In this chapter, our objective is not to scrutinize these works in exhaustive detail, but to extract the key results and significant points.

What is the point of service architectures? Through the different sections of this chapter, we will see that they allow for a response to the concerns of stakeholders in the design of a service. Early in the process, this is achieved by aiding the decision-makers to identify the major challenges of the service (e.g. technical challenges and functional challenges) and their positioning in relation to each other, including from the perspective of cooperation and cost control. Later in the process, it is achieved by supplying the service’s development and deployment teams with a formal and unequivocal statement of requirements concerning the various features to be developed/deployed and the relationships between them. The manager of a development/deployment project can thus reach a clear vision of the tasks to be completed. A service architecture can therefore be considered as the setting for deliberation between the various stakeholders in the design of a service, particularly between the numerous decision-makers (marketing, technical, financial, etc.) and the many development and deployment teams (network, service platforms, etc.). Given that each stakeholder has their own vocabulary, occupation and constraints, this deliberation is publicized by representations (the service architecture) and by people (the architects of the service).

Let us now specify the content of these service architectures, which we will find in different forms later in this chapter. The term “architecture” is usually defined in dictionaries as “the organization of the components that make up a system”. “Organization” is defined as the “way in which a whole is constituted for its functioning”. We could therefore define architecture as the way in which a system is constituted by basic components for its optimal functioning, taking into account technical and economic constraints. Architecture is the response to requirements (services rendered, cost, reusing existing features, etc.); these requirements being fulfilled due to the identification of the constituent components in connection with each other. In each section of this chapter, we will therefore return to this search for constituent components in connection to fulfill requirements.