Q2NS Demo: A Quantum Network Simulator Based on ns-3

Abstract

Q2NS is an open-source quantum network simulator built on ns-3, the de facto standard for classical network simulation. By inheriting ns-3's mature classical stack and event-driven execution model, Q2NS enables faithful co-simulation of quantum-network dynamics and classical signaling, a core requirement for the functioning of any quantum network. Its modular architecture is designed for extensibility, with pluggable quantum-state backends (state-vector, density matrix, stabilizer) and a clean separation between network control and node-level operations. Q2NS comes with a quantum network visualizer Q2NSViz, supporting interactive inspection of both physical- and entanglement-induced connectivity graphs, helping users interpret protocol behavior and entanglement manipulation processes. We present a demonstration of Q2NS, highlighting its ability to capture and simulate the coexistence of quantum and classical communication. The proposed demonstration presents quantum communication scenarios of increasing complexity: from entanglement distribution basics to multipartite graph-state manipulation, complemented by pre-loaded examples in Q2NSViz that require no prior quantum communication or coding experience.

Figures (3)

• Figure 1: A high-level representation of Q2NS simulation environment, and its main hierarchies and entities. Figure reproduced from q2ns-journal.
• Figure 2: Event queue for quantum teleportation of a $\ket{+}$ state in Q2NS. Each protocol step is a timestamped callback.
• Figure 3: Q2NSViz rendering of the distributed graph-state protocol, including tracking of involved qubits and quantum states. The four snapshots show the protocol progression: initial qubit preparation, distribution along quantum channels (purple) and final measurements with classical correction outcomes delivered to the Clients.