Along with the rapid development of quantum information technologies, quantum networks that transmit quantum states have gradually shifted from laboratory to reality. However, the high cost of building a quantum network testbed seriously hinders the research progress of quantum networks, and the existing simulators have been developed with less exposure to network models. To overcome those deficiencies, this article proposes a new discrete-event driven network-layer simulation framework named SimQN, available athttps://github.com/ertuil/SimQN,to provide full functionalities of the quantum networking simulation. The design goal of SimQN is to make it easy-to-configure while providing high performance and accurate simulation capability. We present multiple simulation physical backends to enable different functionalities and reduce computational overhead. The modularized SimQN also provides reusable network protocols and utilities to release the large-scale quantum networking evaluation burden. We present several demonstrations and analyses to illustrate the protocol design and the performance of SimQN.
Along with the rapid development of quantum information technologies, quantum networks that transmit quantum states have gradually shifted from laboratory to reality. However, the high cost of building a quantum network testbed seriously hinders the research progress of quantum networks, and the existing simulators have been developed with less exposure to network models. To overcome those deficiencies, this article proposes a new discrete-event driven network-layer simulation framework named SimQN, available athttps://github.com/ertuil/SimQN,to provide full functionalities of the quantum networking simulation. The design goal of SimQN is to make it easy-to-configure while providing high performance and accurate simulation capability. We present multiple simulation physical backends to enable different functionalities and reduce computational overhead. The modularized SimQN also provides reusable network protocols and utilities to release the large-scale quantum networking evaluation burden. We present several demonstrations and analyses to illustrate the protocol design and the performance of SimQN.
As quantum network technologies develop, the need for teaching and engineering tools such as simulators and emulators rises. QuNetSim addresses this need. QuNetSim is a Python software framework that delivers an easy-to-use interface for simulating quantum networks at the network layer, which can be extended at little effort of the user to implement the corresponding link layer protocols. The goal of QuNetSim is to make it easier to investigate and test quantum networking protocols over various quantum network configurations and parameters. The framework incorporates many known quantum network protocols so that users can quickly build simulations using a quantum-networking toolbox in a few lines of code and so that beginners can easily learn to implement their own quantum networking protocols. Unlike most current tools, QuNetSim simulates with real time and is, therefore, well suited to control laboratory hardware. Here, we present a software design overview of QuNetSim and demonstrate examples of protocols implemented with it. We describe ongoing work, which uses QuNetSim as a library, and describe possible future directions for the development of QuNetSim.
Quantum network simulators are essential for the design and evaluation of quantum network architectures and protocols. However, developing an effective simulator is particularly challenging due to the stateful and non-local nature of quantum entanglement, which requires persistent state awareness and tight in-network coordination. Moreover, because quantum communication protocols inherently rely on classical signaling, a realistic simulator must seamlessly integrate classical and quantum communication primitives within a unified framework. In this work, we presentQ2NS, a modular and extensible quantum network simulation framework built on top of ns-3. The architectural design ofQ2NSenforces a clear separation of concerns between the operational functionalities of modules and entities and the overarching control logic, enabling easy adaptation to heterogeneous and rapidly evolving Quantum Internet paradigms while leveraging ns-3's mature classical networking stack. Additionally,Q2NSincludes a dedicated visualization tool to facilitate developing an intuitive understanding of entanglement-based quantum networking. This design enables accurate modeling of entanglement dynamics and protocol control logic, by providing a flexible, open, and scalable platform for advancing the Quantum Internet research.
Quantum network simulators offer the opportunity to cost-efficiently investigate potential avenues for building networks that scale with the number of users, communication distance, and application demands by simulating alternative hardware designs and control protocols. Several quantum network simulators have been recently developed with these goals in mind. As the size of the simulated networks increases, however, sequential execution becomes time-consuming. Parallel execution presents a suitable method for scalable simulations of large-scale quantum networks, but the unique attributes of quantum information create unexpected challenges. In this work, we identify requirements for parallel simulation of quantum networks and develop the first parallel discrete-event quantum network simulator by modifying the existing serial simulator SeQUeNCe. Our contributions include the design and development of a quantum state manager (QSM) that maintains shared quantum information distributed across multiple processes. We also optimize our parallel code by minimizing the overhead of the QSM and decreasing the amount of synchronization needed among processes. Using these techniques, we observe a speedup of 2 to 25 times when simulating a 1,024-node linear network topology using 2 to 128 processes. We also observe an efficiency greater than 0.5 for up to 32 processes in a linear network topology of the same size and with the same workload. We repeat this evaluation with a randomized workload on a caveman network. We also introduce several methods for partitioning networks by mapping them to different parallel simulation processes. We have released the parallel SeQUeNCe simulator as an open source tool alongside the existing sequential version.
Quantum network simulators are essential for the design and evaluation of quantum network architectures and protocols. However, developing an effective simulator is particularly challenging due to the stateful and non-local nature of quantum entanglement, which requires persistent state awareness and tight in-network coordination. Moreover, because quantum communication protocols inherently rely on classical signaling, a realistic simulator must seamlessly integrate classical and quantum communication primitives within a unified framework. In this work, we present Q2NS, a modular and extensible quantum network simulation framework built on top of ns-3. The architectural design of Q2NS enforces a clear separation of concerns between the operational functionalities of modules and entities and the overarching control logic, enabling easy adaptation to heterogeneous and rapidly evolving Quantum Internet paradigms while leveraging ns-3's mature classical networking stack. Additionally, Q2NS includes a dedicated visualization tool to facilitate developing an intuitive understanding of entanglement-based quantum networking. This design enables accurate modeling of entanglement dynamics and protocol control logic, by providing a flexible, open, and scalable platform for advancing the Quantum Internet research.
Quantum communication brings radically new capabilities that are provably impossible to attain in any classical network. Here, we take the first step from a physics experiment to a quantum internet system. We propose a functional allocation of a quantum network stack, and construct the first physical and link layer protocols that turn ad-hoc physics experiments producing heralded entanglement between quantum processors into a well-defined and robust service. This lays the groundwork for designing and implementing scalable control and application protocols in platform-independent software. To design our protocol, we identify use cases, as well as fundamental and technological design considerations of quantum network hardware, illustrated by considering the state-of-the-art quantum processor platform available to us (Nitrogen-Vacancy (NV) centers in diamond). Using a purpose built discrete-event simulator for quantum networks, we examine the robustness and performance of our protocol using extensive simulations on a supercomputing cluster. We perform a full implementation of our protocol in our simulator, where we successfully validate the physical simulation model against data gathered from the NV hardware. We first observe that our protocol is robust even in a regime of exaggerated losses of classical control messages with only little impact on the performance of the system. We proceed to study the performance of our protocols for 169 distinct simulation scenarios, including trade-offs between traditional performance metrics such as throughput, and the quality of entanglement. Finally, we initiate the study of quantum network scheduling strategies to optimize protocol performance for different use cases.
As quantum networking hardware remains costly and not yet widely accessible, simulation tools are essential for the design and evaluation of quantum network architectures and protocols. However, designing a scalable and computationally efficient quantum network simulator is intrinsically challenging: i) quantum dynamics must be emulated on classical computing platforms while capturing the stateful and non-local nature of entanglement, a quantum resource without any classical networking analog; ii) quantum networking is inherently hybrid, as protocol execution also fundamentally depends on classical signaling. This makes a tight and faithful co-simulation of quantum operations and classical message exchanges a core requirement. In this light, we present Q2NS, a modular and extensible quantum network simulator, built on top of ns-3, designed to seamlessly integrate quantum-network primitives with ns-3's established classical protocol stack. Q2NS adopts a modular architecture that decouples protocol control logic from node- and channel-level operations, enabling rapid prototyping and adaptation across heterogeneous and evolving Quantum Internet scenarios. Q2NS natively supports multiple quantum state representations through a unified interface, allowing interchangeable state-vector, density-matrix, and stabilizer backends. We validate Q2NS through realistic use-case studies and comprehensive benchmarks, demonstrating superior computational efficiency over representative state-of-the-art alternatives, while preserving modeling flexibility. Finally, we provide a dedicated visualization tool that jointly captures physical and entanglement-enabled connectivity and supports entangled-state manipulations, facilitating an intuitive interpretation of entanglement dynamics and protocol behavior. Q2NS offers a flexible, open, and scalable simulation platform for advancing Quantum Internet research.