In this article, we propose two novel core prioritization and crosstalk aware (CP-XT-Aware) algorithms, including CP-XT-Aware with wavelength grouping (CPWG-XT-Aware) and CP-XT-Aware with wavelength reservation (CPWR-XT-Aware), aiming to realize the synergistic transmission of classical and quantum signals in quantum key distribution (QKD)-enabled optical data center networks based on wavelength-division-multiplexing and space-division-multiplexing, For comparison, we introduce the core and wavelength random allocation without XT-Aware, called the CWRA. Analytical simulations show that the both proposed algorithms can simultaneously improve the average secure key rate and reduce blocking probabilities under dynamic traffic scenarios in different network topologies, compared to the CWRA. Particularly, the CPWG-XT-Aware performs exceptionally well in QKD under the low traffic load, while the CPWR-XT-Aware excels under the high traffic load.
In this article, we propose two novel core prioritization and crosstalk aware (CP-XT-Aware) algorithms, including CP-XT-Aware with wavelength grouping (CPWG-XT-Aware) and CP-XT-Aware with wavelength reservation (CPWR-XT-Aware), aiming to realize the synergistic transmission of classical and quantum signals in quantum key distribution (QKD)-enabled optical data center networks based on wavelength-division-multiplexing and space-division-multiplexing, For comparison, we introduce the core and wavelength random allocation without XT-Aware, called the CWRA. Analytical simulations show that the both proposed algorithms can simultaneously improve the average secure key rate and reduce blocking probabilities under dynamic traffic scenarios in different network topologies, compared to the CWRA. Particularly, the CPWG-XT-Aware performs exceptionally well in QKD under the low traffic load, while the CPWR-XT-Aware excels under the high traffic load.
Quantum-key-distribution (QKD) enabled optical networks can provide secure keys for different kinds of applications to ensure the high security of communication processes. As the number of wavelength channels in a single-core fiber is limited, space division multiplexing (SDM) has been considered to be a valuable technique to provide more wavelength resources, which solves the problem of insufficient channel capacity. Due to the rapid expansion of data volume, the SDM-based QKD network has been regarded as an important paradigm. At the same time, resource allocation in multi-core optical networks is a problem worthy of studying. In this work, four routing, core, and wavelength allocation (RCWA) algorithms are proposed in the multi-core optical network for quantum service requests and classical service requests, which are referred to as RCWA without perception (RCWA-WP), RCWA with crosstalk perception (RCWA-XTP), RCWA with spectrum perception (RCWA-SP), and RCWA with core perception (RCWA-CP). Simulations are carried out to evaluate the network performance in terms of blocking probability, key utilization, and average crosstalk intensity. The comparative results indicate that the RCWA-SP algorithm can improve network performance and reduce the blocking probability, while the RCWA-XTP algorithm can reduce inter-core crosstalk during transmission.
Wavelength division multiplexing (WDM) and space division multiplexing (SDM) can be used to implement coexistence of the classical and quantum signals. But some noises are introduced due to the SDM/WDM techniques, such as Raman, Four-wave mixing and inter-core crosstalk noises, which will restrict the performance of the quantum key distribution system (QKD). In this paper, we consider that the classical optical communication system is also affected by such noises. So, in order to improve the performance of the coexistence system based on WDM and SDM, we propose a dual optimized core and wavelength allocation (DOCWA) scheme to realize the synergistic transmission of classical and quantum signals over multi-core fiber. Experiments verify that the proposed scheme can suppress noise photons on classical and quantum channels up to 152.71% and 167.28% compared to the quantum equal frequency spacing scheme, respectively.
We propose a routing and wavelength allocation method in spatial division multiplexing (SDM) based on quantum key distribution (QKD) optical networks. Especially, for the routing and wavelength allocation of quantum services, we design an auxilia/y matrix-based core allocation and a routing method based on inter-core crosstalk (IC-XT) evaluation. For classic services in SDM optical networks, we design a resource allocation method. Through the proposed hybrid resource allocation strategy, the IC-XT of quantum services can be reducedt Moreover, the amount of available secret keys stored by the node has also increased in SDM optical networks.
Optical communications provide high capacity and scalability, while quantum communications, particularly through quantum key distribution (QKD), enable information-theoretic security. However, it still remains challenging to deliver both high throughput communication and long-term security within a hybrid quantum-classical optical network. Specifically, classical optical resources can be reallocated to support QKD, aiming to achieve synergistic resource utilization that surpasses the sum of individual functionalities. In this work, we formulate a networking model that captures the resource allocation constraints, aiming to figure out the necessary conversion of classical optical resources to QKD capacity while maintain the connectivity of classical optical communication. Based on that, we propose a synergistic resource allocation strategy, implemented through heuristic routing, wavelength assignment, and power configuration (SRWP) algorithms. Simulation results demonstrate that the proposed SRWP algorithm, with the objective of network-wide average secret key rate (SKR) maximization (SRWP-ARM), enhances the average SKR from the order of kbit/s to Mbit/s at GHz-level pulse repetition rates. In a 9-node mesh network topology with 50 km links, the algorithm achieves this gain with zero service blocking under a traffic load of 100 erlangs. At a higher load of 300 erlangs, it maintains a service blocking probability as low as 1.24% while still achieving an average SKR of 18.05 kbit/s. This represents the best trade-off between classical service connectivity and secret key generation across all evaluated algorithms.
Optical network security has attracted extensive attentions recently, data encryption is an effective way to enhance the security. Unlike conventional key distribution methods, Quantum key distribution (QKD) is provably-secure. Integrating QKD into optical networks can provide a new paradigm for secure communications. In a QKD integrated optical network, besides the traditional data channels, two additional channels, called quantum-signal channels and public interaction channels, are required to support secure key. Crucially, how to optimally allocate limited wavelength resources to the three channels is emerging as a novel problem. By introducing wavelength division multiplexing (WDM) network and defining the wavelength occupancy factor, this paper designs a dynamic routing, wavelength and time-slot allocation (DRWTA) algorithm for the wavelength allocation in QKD integrated optical network. The simulation results show wavelength scale factor has an adverse effect on the resource utilization rate and the blocking probability. Furthermore, the DRWTA algorithm provides a strategy to allocate wavelength for three types of channels in QKD-WDM networks. The success probability can be improved by exploiting the DRWTA algorithm.
To ensure the security of optical networks in the future, integrating quantum key distribution (QKD) with optical networks is one of the solutions. Moreover, the optical network based on multi-core fiber (MCF) is also one of the ways to improve the transmission capacity. Therefore, we study the integration of QKD into MCF-enabled optical networks. Aiming at the resource allocation problem of MCF-enabled wavelength division multiplexing optical networks, this paper proposes a resource allocation scheme which is suitable for independent-core-transmission of classical signals and quantum signals. For core resource, we propose the alternate core allocation algorithm. For wavelength resource, we propose the iteration-based wavelength allocation algorithm. The overall scheme uses the proposed two algorithms to first allocate the core and then allocate the wavelength. The simulation results show that the proposed scheme has a great improvement in secret key rate (SKR) compared with the benchmark scheme on the regular hexagonal 7-core fiber and 19-core fiber. And the proposed scheme still has good performance under long transmission distance and high classical signal power.