We integrate QKD system and 5G optical fronthaul based on MCF, and experimentally evaluate the performance of QKD system at different bandwidths and modulation formats of classical signals.
Broadband access in optical domain usually focuses in providing a pervasive cost-effective high bitrate communication in a given area. Nowadays, it is of utmost interest also to be able to provide a secure communication to the costumers in the area. Wireless access networks rely on optical domain for both fronthaul and backhaul of the radio access network (C-RAN). Multicore fiber (MCF) has been proposed as a promising candidate for the optical media of choice in nextgeneration wireless. The capacity demand of next-generation 5G networks makes interesting the use of high-capacity optical solutions as space-division multiplexing of different signals over MCF media. This work addresses secure MCF communication supporting C-RAN architectures. The paper proposes the use of one core in the MCF to transport securely an optical quantum key encoding altogether with end-to-end wireless signal transmitted in the remaining cores in radio-over-fiber (RoF). The RoF wireless signals are suitable for radio access fronthaul and backhaul. The theoretical principle and simulation analysis of quantum key distribution (QKD) are presented in this paper. The potential impact of optical RoF transmission crosstalk impairments is assessed experimentally considering different cellular signals on the remaining optical cores in the MCF. The experimental results report fronthaul performance over a four-core optical fiber with RoF transmission of full-standard CDMA signals providing 3.5G services in one core, HSPA+ signals providing 3.9G services in the second core and 3GPP LTEAdvanced signals providing 4G services in the third core, considering that the QKD signal is allocated in the fourth core.
To satisfy the urgent requirements of security for fifth generation (5G) fronthaul network, quantum key distribution (QKD) technique is taken into consideration as a promising way. In this paper, we first propose an architecture for quantum security beyond fifth generation (B5G) fronthaul optical network, which merges facilities of QKD into the architecture of existing 5G fronthaul network, enabling quantum signals to be transmitted with classical signals within the same fiber. Secondly, theoretical model analysis of interference with quantum signals caused by four wave mixing noise is performed. Moreover, the theory of secure key rate calculation under noise interference is introduced. Lastly, the QKD performance in the proposed architecture is evaluated, which leads to the conclusion that even when the quantity of B5G fronthaul optical channels for classical signals reaches up to 12, the secure transmission distance of QKD is still beyond 20km, which satisfies the demand of B5G fronthaul optical network.
The integration of Quantum Key Distribution (QKD) into optical networks has emerged as a promising solution for securing sensitive data transmission in mobile fronthaul applications. However, implementing QKD typically requires dedicated dark fibers, which increases network complexity and deployment costs. This paper explores an approach that leverages Multi-Core Fibers (MCF) to integrate both classical and quantum channels within the same optical fiber, utilizing Space Division Multiplexing (SDM). By dedicating separate cores for quantum and classical channels, the proposed system minimizes the need for additional infrastructure while ensuring secure and efficient communication. Crosstalk between cores, a critical factor in MCF design, is analyzed through simulations, considering parameters such as core pitch and operating spectrum. Results demonstrate the feasibility of achieving minimal inter-core crosstalk for reliable quantum and classical channel coexistence. This study underscores the potential of MCF-based SDM as a cost-effective and scalable solution for future quantum-secured mobile networks.
A research contribution focusing on the Quantum Key Distribution (QKD)-enabled solutions assisting in the security framework of an optical 5G fronthaul segment is presented. We thoroughly investigate the integration of a BB84-QKD link, operating at telecom band, delivering quantum keys for the Advanced Encryption Standard (AES)-256 encryption engines of a packetized fronthaul layer interconnecting multiple 5G terminal nodes. Secure Key Rate calculations are studied for both dedicated and shared fiber configurations to identify the attack surface of AES-encrypted data links in each deployment scenario. We also propose a converged fiber-wireless scenario, exploiting a mesh networking extension operated by mmWave wireless links. In addition to the quantum layer performance, emphasis is placed on the strict requirements of 5G-oriented optical edge segments, such as the latency and the availability of quantum keys. We find that for the dark fiber case, secret keys can be distilled at fiber lengths much longer than the maximum fiber fronthaul distance corresponding to the round-trip latency barrier, for both P2P and P2MP topologies. On the contrary, the inelastic Raman scattering makes the simultaneous transmission of quantum and classical signals much more challenging. To counteract the contamination of noise photons, a resilient classical/QKD coexistence scheme is adopted. Motivated by the recent advancements in quantum technology roadmap, our analysis aims to introduce the QKD blocks as a pillar of the quantum-safe security framework of the 5G/B5G-oriented fronthaul infrastructure.
The rapid evolution of mobile communication technology is propelling us from the era of 5G to the cusp of 6G, which promises ultra-high speeds, ultra-low latency, and seamless global connectivity. However, these ambitious goals require not only significant advancements in traditional communication technologies but also the integration of novel approaches to address emerging security and efficiency challenges. Quantum communication, particularly Quantum Key Distribution (QKD), offers a groundbreaking solution due to its inherent security based on the principles of quantum mechanics. This paper proposes an innovative architecture that combines QKD with Passive Wavelength Division Multiplexing (WDM) for 6G fronthaul networks. The architecture, which includes components for signal transmission, processing, and monitoring, uses WDM to transmit both quantum signals and classical signals over a single fiber, optimizing resource utilization, ensuring security, and enhancing reliability. The quantum signals are detected by single-photon detectors to generate secure keys, while the classical signals carry regular communication data. The passive WDM system efficiently uses fiber resources, is cost-effective, and is easy to upgrade, making it highly compatible with classical optical communication. Extensive simulation experiments are conducted to evaluate the impact of key parameters such as transmission distance, attenuation coefficient, photon count per pulse, dark count rate, and detection efficiency on the secure key rate and quantum error rate. The results indicate that careful optimization of these parameters can substantially enhance system performance, making the architecture highly suitable for high-security transmission scenarios in 6G networks. This research provides new insights into the integration of quantum and classical communications in 6G fronthaul networks, demonstrating the potential of quantum-enhanced 6G networks.
With the global deployment of 5G networks, the demand for high bandwidth and low latency has driven innovations in fronthaul architectures. However, traditional solutions face challenges related to security and signal interference. This paper proposes an innovative quantum-enhanced converged wireless-fiber 5G fronthaul system that integrates quantum key distribution (QKD) technology with a passive wavelength division multiplexing (WDM) architecture to achieve physical-layer secure communication. The system deploys the quantum transmitter (Alice) at the active antenna unit (AAU) side and the receiver (Bob) at the distribution unit (DU) side, leveraging the Heisenberg Uncertainty Principle, quantum measurement collapse theory, and the no-cloning theorem to detect eavesdropping attempts. Simulation results demonstrate the significant impact of noise detection probability, fiber loss, and transmission distance on both the secure key rate and quantum bit error rate (QBER). Key findings highlight the need to minimize fiber loss, reduce transmission distance, lower filter loss, decrease noise detection probability, and improve detection efficiency. These optimizations collectively enhance the secure key rate while reducing the QBER, thereby improving overall system reliability. Remarkably, this solution achieves these security enhancements without requiring large-scale modifications to existing infrastructure, offering a practical and cost-effective upgrade path for current 5G deployments while providing a future-proof foundation for emerging 6G networks. The architecture’s inherent scalability and compatibility make it particularly suitable for high-security applications, including government communications, financial transactions, and critical infrastructure protection—bridging the gap between theoretical quantum security and practical wireless network implementation.