Patent ID: 7330652

Claim:
For a wavelength division multiplexed optical network having a plurality of optical nodes coupled by spans with each optical node capable of receiving at least one optical pre-amplifier for each input fiber and at least one optical post-amplifier for each output fiber, a computer implemented method of selecting amplifier placement, the method comprising: selecting optical services between the plurality of optical nodes, wherein the optical services comprise a plurality of channels, wherein each of the plurality of channels comprises a source node and a destination node, and wherein the plurality of optical nodes are configured in a mesh, ring, or combination thereof topology; selecting an optical power criterion for constraining an initial placement of one or more optical amplifiers in the optical network, the optical power criterion being indicative of a sufficient minimum received power in at least one receiver; wherein the optical power criterion constrains by a node loss algorithm wherein it is determined if a given node has an internal node loss for one or more of the plurality of channels that exceeds a predetermined level, and one or more of a span loss algorithm wherein it is determined if a given span has an internal span loss for one or more of the plurality of channels that exceeds a predetermined level, the span loss algorithm taking into account the internal span loss of a given fiber and one or more transmitter/receiver to output port/input port equivalent losses at one or more end nodes of the span, a path loss algorithm wherein the span loss algorithm is extended to include non-adjacent nodes, an aggregate loss algorithm wherein it is determined if one or more nodes have an aggregate span and band loss for one or more of the plurality of channels that exceeds a predetermined level, and a sequential path search algorithm wherein the power characteristics of one or more of the plurality of channels are analyzed from the source node to the destination node; placing at least one amplifier in accord with the optical power criterion to form the initial placement of amplifiers; and determining a subsequent set of amplifier placement configurations which are consistent with and constrained by the initial placement of amplifiers, wherein constrained by the initial placement of amplifiers comprises one of analyzing all possible configurations of amplifiers having the same number of amplifiers as the initial placement and varying losses of the spans and nodes from the initial placement by a predetermined percentage to identify other possible configurations.