  Vehicle-to-Everything (V2X) communication has become an integral component of
Intelligent Transportation Systems (ITS) due to its ability to connect
vehicles, pedestrians, infrastructure, and create situational awareness among
vehicles. Cellular-Vehicle-to-Everything (C-V2X), based on 3rd Generation
Partnership Project (3GPP) Release 14, is one such communication technology
that has recently gained significant attention to cater the needs of V2X
communication. However, for a successful deployment of C-V2X, it is of
paramount significance to thoroughly test the performance of this technology.
It is unfeasible to physically conduct a V2X communication experiment to test
the performance of C-V2X by arranging hundreds of real vehicles and their
transceiving on-board units. Although multiple simulators based on frameworks
such as NS-3, OMNET++ and OPNET have proven to be reliable and economic
alternatives to using real vehicles, all these simulators are time-consuming
and require several orders of magnitudes longer than the actual simulation
time. As opposed to physical field- and simulation-based testing, network
emulators can provide more realistic and repeatable results for testing
vehicular communication. This paper proposes a real-time, high-fidelity,
hardware-in-the-loop network emulator (RVE-CV2X) based on C-V2X mode 4 that can
provide scalable, reliable and repeatable testing scenarios for V2X
communication. The accuracy of this emulator is verified by comparing it to an
already validated C-V2X simulator based on the NS-3 framework.
