 important applied structure is called Fundamental (Technical) Plans (FP). The plans can indeed also reach beyond pure technique, such as organization. The main author has worked within this area as a consultant and as a teacher for many years, starting in the 1970s. The students have represented operators from all over the world. Historically, after a long stable period during the twentieth century, digitization brought the need for a synchronization plan in addition to a basic set of plans. The area of IN and mobility were the next challenges to the basic 'FP house design'. A main contribution was a mobility management plan. Then IP entered the overall telecom area, giving a new touch to the quality of service plan, urging for a separate security plan and for a controllable convergence. The FP view supports no doubt an orderly convergence between technologies. After all, all technologies have a common target: to connect communicating parties in a satisfactory way, technically and economically. Proceeding with the plans, the deregulation and the evolving global networks demanded more attention to the establishment of an interconnect plan. In this book another two areas are included, without being necessarily labelled FPs: service layer enablers (other than those belonging to established plans; for example content-oriented functions, such as positioning) and economy of service. A main target for economy of service is to enable voice over IP with reasonable efficiency. Efficient voice and video coders, header compression techniques, many WAP features and concentrating and aggregating equipment can be included within the scope of economy of service. A few more fundamental plans may be justified in practice, depending on the techni- cal context. Regarding FP I would like to refer to ITU and an extensive cooperation during the 1990s with Herbert Leijon. See for example: htp://www.itu.int/itudoc/itu-d/dept/psp/ssb/mpg/ch08.html http://www.itu.int/itudoc/itu-d/dept/psp/ssb/planitu/plandoc/corplan.pdf http://www.itu.int