Optical Metro Network Design with Low Cost of Equipment

New arising 5G services will pressure optical metro networks with unprecedented requirements. As operators' revenues are not scaling accordingly, several technical directions to design low-cost optical metro networks are being investigated. In this study we observe that operators can jointly i) enforce Filterless Optical Network (FON) architecture, hence removing costly Wavelength Selective Switches, ii) leverage relatively short links in metro networks to reduce the number of optical amplifiers (OAs), iii) place amplifiers intelligently to maximize signal quality (SNR), hence employing higher-order modulation formats (MF) and reducing the number of transponders. To quantify the achievable cost-reduction we develop a Quality-of-Transmission (QoT) aware planning tool, based on Genetic Algorithm, for joint optimization of fiber tree establishment (inherent to FON), OA placement and MF assignment. Results obtained over a realistic topology show that the proposed design achieves overall (4-8)% equipment cost savings compared to baseline optical network deployment, without affecting QoT.