Performance Analysis on Co-Existence of COW-QKD and Classical DWDM Channels Transmission in UK National Quantum Networks
Duan Xiao, Joseph Pearse, A. Wonfor, Catherine White, Arash Bahrami, Andrew Straw, Tim Edwards, Richard V. Penty, Andrew Lord, Rupesh Kumar, Timothy P. Spiller
Abstract
To analyse and evaluate the physical layer performance of a U.K. national quantum network (UKQNtel) utilising COW-QKD, in O band, integrated with 500 Gb/s encrypted data, in C band, over 121 km between BT Labs and the University of Cambridge, a theoretical model encompassing COW-QKD and Raman scattering noise is developed and fitted with real-world experimental data. Different physical mechanisms underpinning the link performance are identified and discussed. The model developed in this work also provides a preliminary technical guidance for future UKQNtel upgrade and expansion, as well as potentially useful insights for quantum-secured networks design prior to practical deployment.