Protection of passive optical network by using ring topology

This article proposes an innovative method of passive optical networks' protection by using ring topology. Passive optical networks (PONs) are typically used in modern high-speed access networks, but there are also several specific applications, such as in business, office, army or science sector, which require a complex protection and backup system against failures and malfunctions. A standard tree or star topologies, which are usually used for PONs, are significantly vulnerable mainly against the malfunctions and failures of Optical Line Termination (OLT), which is a central optical unit of a whole PON. On the other hand, the application of a ring topology for PON can offer several interesting advantages. That is why this paper brings and innovative method for protecting PONs by using ring topologies. The method is described in the article and scenarios and calculations using symmetric or asymmetric passive optical splitters are included as well.