strated, but the main evolution directions are also considered. In any case, a large volume of numerical examples gives solid structure to the different subjects. While in the first seven chapters we have mainly considered engineering techniques, we enter the research labs in Chapters 8 through 10 to present the latest techniques in the telecommunication field that will shape the long-term network evolution. The book concludes with a chapter on access optical technology. Introduction 1.2 Using This Book Requisites for a full exploitation of this book's potential are the technical culture typical of an engineer (not necessarily one working in the field) or of an advanced PhD student in engineering or physics as well as a very basic knowledge of telecommunication services. Following are examples of potential users of this book: The industry manager, who can have a clear and complete idea of the helping him to consider correctly also key elements that are at the edge of his or her core area of com- petence. Due to its strong focus on interdependence, the book offers critical help in the decision process and could well become a working instrument for technical and market- ing managers. The designer, who can have a global idea of new technologies SO as to channelize his or her work in the most suitable direction and to make design choices having a complete view of the possible alternatives. The university professor, who can study the connection between market trends and tech- nology evolution among the different technical areas (e.g., technology and network archi- tecture) SO as to transmit this to the students. Due to its structure, the book should be useful in carrying out research for an up-to-date university course in tune with the latest realistic trends. Finally, a university professor can also use this book to update himself or herself on aspects of telecommunications that fall within the core area of his or her competencies. The senior student, who can use this book to decide where to direct his or her activit