Abstract: A method for the protection of fiber optic ring-shaped transport networks, the networks including network elements connected by spans, optical paths being installed between the network elements, the method including the steps of providing each network element with information concerning the network architecture; providing each network element with information concerning configuration data of the network elements; providing each network element with information concerning criteria for triggering the mechanism; establishing an information exchange protocol comprising a set of messages and of rules; establishing a traffic rerouting method, wherein the configuration data include the ring map, the traffic map, the wavelength and the bit rate concerning every path.

Abstract: Method for upgrading a fiber optics network ring, in particular MS-SPRING ring, providing for laying in a first time a fiber optics network ring having a first number of fiber optics and for adding in a second time the functionalities associated to a ring having a second number of fiber optics, said second number of fiber optics being greater than the first. According to the invention, said functionalities are obtained by providing a ring that uses on the fibers that constitutes the first number of fiber optics a bi-directional working functionality.

Abstract: A method is described for the protection of fiber optic ring-shaped transport networks, said networks comprising network elements connected by spans, optical paths being installed between said network elements, said method comprising the steps of providing each network element with information concerning the network architecture; providing each network element with information concerning configuration data of the network elements; providing each network element with information concerning criteria for triggering the mechanism; establishing an information exchange protocol comprising a set of messages and of rules; establishing a traffic rerouting method, wherein said configuration data comprise the ring map, the traffic map, the wavelength and the bit rate concerning every path.