Coherent Pluggable Optical Transceivers: Performance Versus Interoperability

Coherent optical transceiver evolution has been the major driver for the cost-effective increase of capacity in optical networks, enabling ever higher traffic volumes across metro, regional, long-haul and submarine networks. Traditionally, these devices have been proprietary and embedded in dedicated line cards, which are deployed and managed within the transport network domain. With the emergence of implementation and multi-source agreements for coherent optical transceivers in pluggable form factors, savings in cost, power consumption and footprint can now be realized. Furthermore, by installing these transceivers directly in routers/switches the long-envisioned IP-over-DWDM architecture becomes possible. Nevertheless, extending the benefits of coherent pluggable transceivers to network segments that have stringent performance requirements, such as regional and long-haul networks, is challenging. This paper compares the deployment in a reference regional network of coherent pluggable transceivers that retain interoperability (at the expense of limited performance) and proprietary coherent pluggable transceivers designed for best-in-class performance. Simulation results show that the latter allow to increase usable network capacity while also using fewer transceivers, suggesting they are likely more suitable to address the demanding regional and long-haul network segments.