Protection cycles in mesh WDM networks

A fault recovery system that is fast and reliable is essential to today's n etworks, as it can be used to minimize the impact of the fault on the opera tion of the network and the services it provides. This paper proposes a met hodology for performing automatic protection switching (APS) in optical net works with arbitrary mesh topologies in order to protect the network from f iber link failures. All fiber links interconnecting the optical switches ar e assumed to be bidirectional. In the scenario considered, the layout of th e protection fibers and the setup of the protection switches is implemented in nonreal time, during the setup of the network. When a fiber link fails, the connections that use that link are automatically restored and their si gnals are routed to their original destination using the protection fibers and protection switches. The protection process proposed is fast, distribut ed, and autonomous. It restores the network in real time, without relying o n a central manager or a centralized database. It is also independent of th e topology and the connection state of the network at the time of the failu re.