Illinois Express Quantum Network (IEQNET) -- Metropolitan-Scale Experimental Quantum Network testbed

The Illinois Express Quantum Network (IEQNET) is a program to realize a metro-scale quantum network testbed over deployed fiber using currently available technology. IEQNET consists of multiple sites (Q-nodes) that are geographically dispersed in the Chicago metropolitan area. Q-nodes generate or measure quantum signals such as entangled photons and communicate the results via conventional communication channels. The entangled photons in IEQNET nodes are generated at multiple wavelengths, and are selectively distributed to the desired users via optical switches. We will describe the network architecture of IEQNET, including the Internet-inspired layered hierarchy that leverages software-defined-networking (SDN) technology to perform traditional wavelength routing and assignment between the Q-nodes. Using SDN allows us to decouple the control and data planes, with the control plane being entirely classical. An important goal of IEQNET is to investigate to which extent the control plane can coexist with the data plane using the same fiber lines. We envision IEQNET to aid in developing robust and practical quantum networks by demonstrating metro-scale quantum communication tasks such as entanglement distribution and quantum-state teleportation.