Patent ID: 7369767

Claim:
A method of determining a spectral route in an optical telecommunications network between a departure node and an arrival node belonging to said network, the method comprising a step of using a routing method to determine a spatial route connecting said departure node to said arrival node, said spatial route comprising a sequence of route segments, each route segment directly interconnecting two nodes of said network and being capable of conveying at least one wavelength or wavelength band, the method being characterized in that it further comprises the following subsequent steps: identifying at least one wavelength or wavelength band that can be used along each of said route segments of said spatial route; constructing a graph made up of vertices and arcs interconnecting vertices in pairs, in which: each vertex is associated with one of said route segments and represents a wavelength or wavelength band that can be used along said associated route segment; and each arc is associated with one of said nodes of said spatial route and joins two consecutive vertices associated respectively with consecutive route segments interconnected via said associated node, and represents a transition from a first wavelength or wavelength band to a second wavelength or wavelength band represented respectively by said consecutive vertices, said transition corresponding to a wavelength conversion that can be performed by said associated node, each of said arcs being given a distance corresponding to a cost that is allocated to said transition; and determining the shortest path through this graph by an algorithm for determining shortest path.