rally located in the core network nodes. The core network is divided into several subareas, different for capacity, extension and role: backbone, metro core, and regional. The characteristics of these different subnet- works are analyzed in detail. The end user has the possibility to access the resources of the core network through the access network. Architectures and technologies of the access network, which are key for the carriers' success, are also analyzed, focusing particularly on the evolution from the copper-based access to the fiber-based access. In any case, the analysis has been presented keeping engineering practice in mind, even when complex concepts of modern physics or of control structures have been considered. Instead of general and abstract results, the book tries, through a great number of exam- ples, to evidence the practical elements of the design of key communication equipment. Some of these examples are synthetic exercises of design that are conceived to put the reader in front of a realistic coexistence of all the elements in a single equipment, instead of insisting on the separate analysis of different design points. In every case, for simple components and for the more complex equipment, realistic values of the system parameters have been reported by collecting information from the products available on the market. In this way, the reader is provided with an extended database of what present-day technology can do, which is necessary to understand, at first glance, if a set of requirements is within the reach of the technology. In this context, Chapter 2 is devoted to an analysis of the recent history and of the pres- ent status of the telecommunication market, SO as to be able to derive requirements for the network evolution from market trends. Chapter 3 gives a general overview of the current networking techniques, while Chapters 4 through 7 review the core network in detail from the technology, network element, and architecture points of view. Not only are consolidated techniques illu