The wireless control of modular multilevel converter (MMC) submodules was recently proposed. The success of the control depends on specialized control methods suitable for wireless communication and a properly designed wireless communication network in the MMC valve hall while aiming for low latency and high reliability. The wireless communication in the hall can be affected by the electromagnetic interference (EMI) of MMC submodules, voltage and current transients. In this article, firstly, a wireless communication network based on 5G New Radio is designed for an example full-scale MMC valve hall. After that, the radiated EMI characteristics of the MMC submodules with different voltage and current ratings and two dc circuit breakers are measured. The effects of EMI on wireless communication in the multi-GHz frequency band are tested. The interference from the components is confined below $\mathrm {500 \text {M} \text {Hz} }$ , and the wireless communication with $\mathrm {5825 \text {M} \text {Hz} }$ center frequency is not affected by the interference.