Passive optical networks (PONs) are telecommunication networks that provide services to users by no active elements. Only passive elements are used in the network to transmit the information and signals between users as well as between users and the companies operating the telecommunication networks. PON have evolved from their infancy as fine and economical ideas, toward a long-term, reliable, and cost-effective technical solutions for providing access to most users to high-speed Internet by Fiber-to-the-Home (and similar) solutions. PON are still evolving, providing the base of multiple standardized networks and in combination with different technologies are growing into metropolitan networks and extensions of mobile communications. Herein, we overview the state of the art of passive optical networks as well as their basic concepts. This work is divided into four sections: In Section 1, we give a summary of the main concepts of passive optical networks. Sections 2 and 3 introduce the most important features of ITU-T Recommendations and IEEE Standards for passive access networks, respectively. Finally, Section 4 concludes the article with an overview on the future trends of PONs for access networks.

This is the preprint version of the article “Passive Optical Networks, Introduction” by Jose Antonio Altabas, Samael Sarmiento Hernández and José Antonio Lázaro Villa, accepted for publication in Wiley Encyclopedia of Electrical and Electronics Engineering (2018). http://dx.doi.org/10.1002/047134608X.W8373