Quantum networks are expected to enable distributed quantum computing, secure communication, and global entanglement distribution. However, operating such networks presents significant challenges, including stochastic quantum processes, fragile entanglement resources, dynamic topology, and cross-layer control requirements. Current quantum network control architectures largely rely on centralized or hierarchical controllers inspired by classical software-defined networking (SDN). While effective for small testbeds, these approaches face scalability, latency, and reliability limitations as quantum networks grow.
Quantum networks are expected to enable distributed quantum computing, secure communication, and global entanglement distribution. However, operating such networks presents significant challenges, including stochastic quantum processes, fragile entanglement resources, dynamic topology, and cross-layer control requirements. Current quantum network control architectures largely rely on centralized or hierarchical controllers inspired by classical software-defined networking (SDN). While effective for small testbeds, these approaches face scalability, latency, and reliability limitations as quantum networks grow.
The realization of the Quantum Internet promises transformative capabilities in secure communication, distributed quantum computing, and high-precision metrology. However, transitioning from laboratory experiments to a scalable, multi-tenant network utility introduces deep orchestration challenges. Current development is often siloed within physics communities, prioritizing hardware, while the classical networking community lacks architectural models to manage fragile quantum resources. This tutorial bridges this divide by providing a network-centric view of quantum networking. We dismantle idealized assumptions in current simulators to address the "simulation-reality gap," recasting them as explicit control-plane constraints. To bridge this gap, we establish Software-Defined Quantum Networking (SDQN) as a prerequisite for scale, prioritizing a symbiotic, dual-plane architecture where classical control dictates quantum data flow. Specifically, we synthesize reference models for SDQN and the Quantum Network Operating System (QNOS) for hardware abstraction, and adapt a Quantum Network Utility Maximization (Q-NUM) framework as a unifying mathematical lens for engineers to reason about trade-offs between entanglement routing, scheduling, and fidelity. Furthermore, we analyze Distributed Quantum AI (DQAI) over imperfect networks as a case study, illustrating how physical constraints such as probabilistic stragglers and decoherence dictate application-layer viability. Ultimately, this tutorial equips network engineers with the tools required to transition quantum networking from a bespoke physics experiment into a programmable, multi-tenant global infrastructure.
ABSTRACT Quantum networks development is crucial to realizing a production‐grade network that can support distributed sensing, secure communication, and utility‐scale quantum computation. However, the transition from laboratory demonstration to deployable networks requires software implementations of architectures and protocols tailored to the unique constraints of quantum systems. This paper reviews the current state of software implementations for quantum networks, organized around a three‐plane abstraction of infrastructure, logical, and control/service planes. We cover software for both designing quantum network protocols (e.g., SeQUeNCe, QuISP, and NetSquid) and operating testbeds, with a focus on essential control/service plane functions such as entanglement, topology, and resource management, in a proposed taxonomy. Our review highlights a persistent gap between theoretical architecture and protocol proposals and their realization in simulators or testbeds, particularly in dynamic topology and network management. We conclude by outlining open challenges and proposing a roadmap for developing scalable software architectures to enable hybrid, large‐scale quantum networks.
As an important support for quantum communication, quantum key distribution (QKD) networks have achieved a relatively mature level of development, and they face higher requirements for multi-user end-to-end networking capabilities. Thus, QKD networks need an effective management plane to control and coordinate with the QKD resources. As a promising technology, software defined networking (SDN) can separate the control and management of QKD networks from the actual forwarding of the quantum keys. This paper systematically introduces QKD networks enabled by SDN, by elaborating on its overall architecture, related interfaces, and protocols. Then, three-use cases are provided as important paradigms with their corresponding schemes and simulation performances.
The creation of the future quantum Internet requires the development of new systems, architectures, and communications protocols. As a matter of fact, the optical fiber technology is affected by extremely high losses; thus, the deployment of a quantum satellite network (QSN) composed of quantum satellite repeaters (QSRs) in low Earth orbit would make it possible to overcome these attenuation problems. For these reasons, we consider the design of an ad hoc quantum satellite backbone based on the Software-Defined Networking (SDN) paradigm with a modular two-tier Control Plane (CP). The first tier of the CP is embedded into a Master Control Station (MCS) on the ground, which coordinates the entire constellation and performs the management of the CP integrated into the constellation itself. This second tier is responsible for entanglement generation and management on the selected path. In addition to defining the SDN architecture in all its components, we present a possible protocol to generate entanglement on the end-to-end (E2E) path. Furthermore, we evaluate the performance of the developed protocol in terms of the latency required to establish entanglement between two ground stations connected via the quantum satellite backbone.
The key objective of the Quantum Internet is the distribution and manipulation of entanglement to enable unprecedented applications. This requires a radical departure from classical Internet design principles, such as the end-to-end argument, due to the inherently stateful and non-local nature of entanglement, which demands coordinated in-network operations and persistent state awareness. To this end, we propose a novel hierarchical Quantum Internet architecture centered on the concept ofEntanglement-Defined Controller(EDC). This architectural design constitutes the foundational layer, by enabling a clear separation between control and data planes. While necessary, this separation is insufficient to manage entanglement resources, requiring aquantum-native control plane. Consequently, we propose aquantum addressing schemethat embeds quantumness directly into node identifiers, allowing the network to natively track and manipulate entanglement as a dynamic resource. Built upon these two interdependent pillars – EDC-based architecture and quantum addressing – we design aquantum-native routing protocolthat achieves scalability through compact routing tables, by efficiently operating over entanglement-defined topologies. Finally, we design aquantum address splittingfunctionality based on Schrödinger’s oracles that generalizes classical match-and-forward logic to the quantum domain. Collectively, these contributions demonstrate, for the first time, the fundamental advantages of quantum-by-design network control for enabling scalable quantum networking.
The use of quantum satellites can be significant paving the way for novel telecommunications network paradigms, making it possible to connect remote regions. Given the rapid development of quantum communication technologies, many studies are focusing on quantum satellites interconnections via Free Space Optic (FSO), especially considering that the adoption of wired alternatives did not achieve significant results, mainly in terms of covering long distances. In this context, the global interconnection of Quantum Computers (QCs) through the so-called Quantum Internet (QI) compels for new communications and computing architectures such as Quantum Cloud (QCloud). To this purpose, the deployment of Satellite Quantum Networks (SQNs) could make easily available innovative services spanning from security to advanced computing, especially by using Software-Defined Networking (SDN) technology, which is considered a significant enabler for the management of SQNs. Moreover, considering the rapid variability of the topology in terms of nodes and links features, the paper proposes a specific Temporal Networks (TNs) optimization strategy embedded in an SDN Controller ecosystem, dynamically optimizing the path durations to achieve the highest entanglement rate, while limiting the disconnections. Performance evaluation in a worst case scenario shows that the proposed framework is able to support distributed applications by exploiting all the connection opportunities.