Analysis and Testing of Next-Generation Passive Optical Access Network
In the past decade, we have witnessed the rapid development of the Internet as well as corporate networks. The evolution of mobile Internet, global digitalization, cloud computing, and the Internet of Things has consistently increased the bandwidth requirements across all segments of computing systems, from access networks to core networks. Under these conditions, optical access networks have emerged as an optimal solution for the implementation and further development of the access segment due to their service transparency, economic efficiency, energy savings, and higher security compared to other access networks. The International Telecommunication Union (ITU), together with the Full-Service Access Network (FSAN) organization, has established the necessary development steps and standards for next-generation access networks to meet the increasing capacity demands. Passive optical networks (PON) utilize passive components with low energy requirements, eliminating the need for power in the optical fiber distribution network. PON is currently primarily deployed in optical access networks as a Fiber to the Home (FTTH) solution, enabling triple-play broadband services of voice, data, and video over a single optical fiber shared among multiple users in residential areas. Managing these networks requires adequate tools for efficient cost monitoring. This includes troubleshooting with the ability to remotely differentiate between equipment failures and fiber breaks, followed by network localization, which is critical for telecommunications operators. The use of Optical Time-Domain Reflectometer (OTDR) techniques is widespread in point-to-point optical network topologies.
The objective of this master’s thesis is to provide a comprehensive overview of the state of passive optical networks, exploring both theoretical concepts and practical applications. On the one hand, this work presents a complete and systematic review of passive optical access networks, addressing current research topics as well as key operational issues related to the guidelines for designing and implementing passive optical network architectures. Additionally, testing equipment for passive optical networks is presented, with detailed analysis of optical power and its measurement using optical power meters. On the other hand, the thesis analyzes a case study of FTTH network implementation in Serbia, encompassing conceptual design, adopted technologies, protocols, acceptance testing procedures, and service commissioning. The study includes methodologies employed by designers to calculate power budgets and transmission efficiency concerning required distances, operating wavelengths, split ratios, and minimum transmission power requirements. A step-by-step testing procedure is outlined to verify compliance with ITU standards and equipment specifications from various manufacturers. The results of OTDR measurements are graphically presented and thoroughly analyzed to verify the network's compliance with relevant standards and specifications.