The objective of the second volume of the Handbook of Telecommunications Economics is to highlight the economic aspects of the evolution of communications technologies beyond the basic fixed-line telephony infrastructure that was covered in Volume 1. In that book, structural, regulatory and competition policy issues with respect to a well-known technology were covered. Yet, technological options have increased in a quantum manner. Fuelled by the creativity of entrepreneurs and policy-makers world wide, it is safe to infer that a process of creative destruction is well underway. Volume 2 covers the major technological developments and tracks the changes in these developments linking them to the ways that both communications can take place and that institutions and policies can evolve. Written by world leading scholars in a manner that will be appreciated by a wide audience of academics and professionals, the fifteen detailed reviews that make up this book provide an academic perspective on these contemporary changes.