Transceiver Count Reduction in Filterless Metro-Aggregation Networks Using DSCM

This study investigates the impact that Point-to-Multipoint (P2MP), traffic growth, and optical aggregation have on the performance of the optical systems and on the necessary hardware required to ensure connectivity across the full network. We leverage the examples of realistic topologies provided by Telecom Italia (TIM) to generalize the network characteristics and allow for statistical analysis of horseshoe-based metro-aggregation scenarios. By comparing the necessary hardware (i.e., number of optical transceivers) in Point-to-Point (P2P) and in P2MP operation, our investigation reveals the extent to which Digital Subcarrier Multiplexing (DSCM) in combination with optical aggregation allows to reduce the number of pluggable units that need to be deployed. In the simulations, under the assumption of a pay-as-you-grow provisioning strategy, we observe a reduction in transceivers in the 33%-45% range depending on the aggregation level and traffic volume after 10 years of operation. In addition to this, we are able to calculate the maximum required cost of the DSCM-capable transceivers with respect to more traditional P2P solutions to produce cost-effective deployments. These results, presented as a function of traffic volume, level of optical aggregation, and relative cost with respect to P2P transceivers, provide an understanding of the overall cost of acquiring DSCM-based pluggable units, and demonstrate that, even though the price point might be higher, the reduction in terms of hardware due to adopting a P2MP approach compensates this aspect and can still allow for the deployment to be more cost-effective.