Patent ID: 7187862
Filing Date: 2007-03-06
Classification: H04B,H04J

Abstract:
1. A method of detecting and locating faults in an optical multi channel network composed of network nodes, the method including: assigning sub-carrier pilot tones to a number of the nodes comprising Network Elements NE, wherein each of said tones has a frequency different from those of multiple optical channels of the network and different from those of sub-carrier pilot tones assigned to other network nodes, applying said different sub-carrier pilot tones to any signal added to the network via the respective nodes, checking presence of one or more of the sub-carrier pilot tones at one or more points of the network, and, based on results of the checking, locating a faulty section of the network in case a, fault occurred, wherein the step of locating of a faulty section is based on detecting, at a particular point of the network, absence of a sub-carrier pilot tone which should be present at said point, said step of locating comprises: relating said tone to the network section associated with the Network Element (NE) to which said tone is assigned, and comparing the information on presence of one or more of the sub-carrier pilot tones with a correct picture of the network formed from information on the optical channels added and dropped at each of said Network Elements, and on sub-carriers assigned to each of said Network Elements.