Cost-Optimized Planning for Supporting 100 Gb/s and 40 Gb/s Services over Channel Count-Limited Optical Transport Networks

The increasing traffic demand resulting from the widespread use of information and communication technologies is impelling network operators to upgrade the capacity of their existing transport network facilities. Recent advances in the scientific community have led to the first developments in serial 100 Gb/s technology that could provide an adequate solution for solving the capacity expansion problem. Nevertheless, given the complexity of 100 Gb/s transceiver equipment, the initial costs may refrain early adoption of the technology, leading carriers to invest in more cost-effective alternatives. Embedded in the optical transport network (OTN) functionality portfolio, traffic grooming and virtual concatenation can be exploited in order to optimally combine 40 Gb/s and 100 Gb/s equipment for supporting mixed line rate (MLR) demands. Hence, this work proposes an optimization framework for designing optical transport infrastructures with the objective of minimizing the network costs directly related to transceiver and regenerator equipment. The framework models the problem via an integer linear programming formulation that takes into account the relative cost, the maximum optical reach, and the capacity of each optical interface, as well as the optical channel limit per fiber link. As a result, the proposed method is able to select the equipment type and the routing path for each connection which correspond to the most cost-effective solution satisfying the 100G and 40G service demands.