This book provides detailed information on a low-cost, high-speed infrastructure to support applications and services based on 5G/6G, the Internet of Things (IoT), smart cities, and fiber-to-the-x (FTTX). The contents will serve as a ready reference for researchers, design engineers, network operators, and service providers, as well as graduating engineers interested in pursuing careers in the optical access network domain. The book is a road map for designing and developing access networks for a variety of applications, including smart cities and long-distance high-speed access networks. The book is useful for undergraduate, postgraduate, and research students, particularly in developing South-East Asian countries.