Availability-Aware Key Service With Dedicated Path Protection in Quantum Key Distribution Optical Networks
Bowen Chen, Bing He, Nianying Zheng, Hong Chen, Weidong Shao, Limei Peng, Pin‐Han Ho, Vimal Bhatia · Journal of Lightwave Technology · 2025
Quantum key distribution (QKD)-based optical networks utilize quantum mechanics to secure communications by establishing secure, albeit expensive, quantum channels. A critical criterion for these QKD networks is to ensure network availability, which requires each service to adhere to a minimum unavailability constraint to maintain maximum network availability. This paper tackles the challenge of providing dedicated path protection for a select set of key services within QKD optical networks, adhering to specific unavailability constraints to ensure the gap between working and protection paths' unavailability remains within the allowable limit for each services. Considering the constraints of the limited timeslot resources and unavailability for the dedicated-path protection, we develop integer linear programming (ILP) models, to minimize the overall timeslot consumption in QKD optical networks. Additionally, we propose two novel algorithms for timeslot and availability management as minimum timeslot consumption (MTC) algorithm, and maximum availability (MA) algorithm to reduce the timeslot consumption. Simulations indicate that the ILP model based solution achieves the lowest timeslot consumption, however, it requires considerably more processing time compared to the proposed MTC and MA algorithms. Moreover, the MTC and MA algorithms outperform conventional dedicated-path protection (CDP) and fixed routing (FR) algorithms in reducing total timeslot consumption and improving average unavailability.