A Survey on Reliability Evaluation of Optical Networks

In the past decade, rapid advancements in communication technology have fundamentally transformed methods of connection and communication in the digital age. Optical networks have emerged as indispensable communication infrastructures due to their high per-channel transmission rates, massive aggregate capacity enabled by multiplexing technologies, and excellent resistance to electromagnetic interference. The enormous transmission capacity of optical networks has greatly facilitated the development of various businesses and applications. Therefore, ensuring the reliable operation of optical networks is crucial. One of the key conditions for ensuring the reliable operation of optical networks is the ability to accurately measure or evaluate their reliability. There are many methods for the evaluation of optical network reliability. Each method has its applicable scope, advantages, and limitations. However, with the continuous development of new technologies like 6G, reliability evaluation will face higher demands and more complex scenarios. Currently, there is no comprehensive systematic literature survey on the existing optical network reliability evaluation methods. Hence, the research focuses on evaluation methods for optical network reliability. Several essential concepts in evaluating optical network reliability are clarified, factors affecting its reliability are summarized, evaluation metrics are analyzed, and evaluation methods are reviewed. Then, methods to enhance the reliability of optical networks are outlined, and the trade-offs between cost/energy consumption and reliability are discussed. Finally, some significant future challenges are described, and corresponding open research topics are proposed. This survey provides valuable references for designing more reliable optical networks or developing highly reliable operation and maintenance strategies.