Wavelength assignment in quantum access networks with hybrid wireless-fiber links

Abstract

We propose a low-complexity near-optimal wavelength allocation technique for quantum key distribution access networks that rely on wavelength division multiple access. Such networks would allow users to send quantum and classical signals simultaneously on the same optical fiber infrastructure. Users can be connected to the access network via optical wireless or wired links. We account for the background noise present in the environment, as well as the Raman noise generated by classical channels, and calculate the secret key generation rate for quantum channels in the finite-key setting. This allows us to examine the feasibility of such systems in realistic scenarios when the secret key exchange needs to be achieved in a limited time scale. Our numerical results show that, by proper choice of system parameters for this noisy system, it is possible to exchange a secret key in tens of seconds. Moreover, our proposed algorithm can enhance the key rate of quantum channels, especially in high noise and/or high loss regimes of operation.

Finite-key analysis of loss-tolerant quantum key distribution based on random sampling theory

“…Clearly, E[K 2 ] = (1 − p)n, and therefore n = E[K 2 ]/(1 − p). Using the inverse multiplicative Chernoff bound [25,31,32], we have that…”

Quantum key distribution and beyond: introduction

“…This will enable high-rate low-noise long-distance satellite QKD links to be established. Novel structures for QKD networks have been presented at access, with wireless functionality [2], and core, featuring reconfigurability [3], layers with Cao et al using software defined networking concepts to design QKD networks [4]. There is also an increasing interest in applying machine learning techniques to optimize the performance of QKD systems [5][6][7].…”

“…There is also an increasing interest in applying machine learning techniques to optimize the performance of QKD systems [5][6][7]. The security of practical implementations has also been addressed by devising hacking strategies [8][9][10], with their corresponding countermeasures, as well as by accounting for realistic imperfections and finite-key effects in the security analysis [2,11]. The feature issue also covers some less conventional protocols [12,13], relying on ambiguous state discrimination, as well as insight into multi-mode and high-dimensional QKD systems [14,15].…”

Quantum and classical communications on shared infrastructure

“…In addition to the above conventional techniques to reducing the crosstalk noise, there are other methods, which can enhance our ability to use our spectral resources efficiently. One of the proposed techniques relies on optimal or near-optimal wavelength assignment [11]- [13]. In this technique, we take advantage of asymmetric form of the Raman spectrum to place our QKD channels in positions where the total collected crosstalk noise is minimum.…”

“…We also present low-complexity near-optimal wavelength allocation techniques that can be used in a dynamic setting. In all cases, the finite-key effects will also be considered [13], [18].…”