What is beyond 50G: future standards of optical access networks [Invited]

In the past two decades, optical access networks have been widely deployed by operators around the world. The global optical access network market reaches about 1 billion users with a revenue of over 10 billion US dollars. As strategic tools to facilitate mass production, the optical access network standards play a crucial role in driving the product deployment and market growth. This paper overviews the latest effort in international standards bodies on the next generation optical access networks. It discusses projects in this area within the International Telecommunication Union's Telecommunication Standardization Section (ITU-T), the IEEE, and the European Telecommunications Standards Institute (ETSI). Promising technologies are investigated with the goal of providing rates beyond 50 Gbps. Challenges are highlighted to satisfy the requirements on balancing access rates, loss budgets, and cost. Candidate systems are analyzed in three categories: point-to-multipoint (PtMP), point-to-point (PtP), and new applications. These standardization endeavors will jointly guarantee optical access networks as the premiere solution of wireline broadband access.