"The book outlines the current situation of the telecommunication network and the different alternatives for network evolution. It provides a systematic view of the network design problem, underlining its links between different aspects. It presents the engineering knowledge needed to construct a network evolution strategy, examines the elements influencing telecommunications network evolution and their interdependence, and supplies a complete review of the architecture alternatives. The content ranges from high level architectural elements to component physics, with a focus on enlightening the same problem from different points of view"-- "Preface The telecommunication infrastructure is perhaps the most impressive network developed by humankind. Almost all the technical knowledge forming the basic human know-how is exploited in the telecommunication network: from quantum field theory needed to study optical amplifier noise to software architectures adopted to design the control software of the network, from abstract algebra used in error correcting codes and in network design algorithms to thermal and mechanical modeling adopted in the design of telecommunication equipment platforms. The network is present almost everywhere in the world, allowing seamless communication of sounds and images through a chain of different types of equipment produced by several equipment vendors. Communication is carried out smoothly not only in normal conditions, but its quality is also monitored continuously, allowing it to survive failure of individual components and even to maintain a certain degree of functionality in case of catastrophic events like earthquakes. The aim of this book is to present the telecommunication network as a whole, adopting a practical approach that does not evidence only recent developments and research directions, but also engineering subjects and key market needs that are no less important in guaranteeing the network operation standard. The great attention to standardization, both in the description of standards and in the bibliography, is "an" before "integral" part of this strategy. The only area not covered by this book, out of a generic discussion, is constituted by radio systems. Considering that cellular systems are part of the access area and that radio bridges are used only in emergency situations out of the access area, this mainly impacts the way in which access to the network is"--