LAUSR

Wireless communication technologies play a key role to support the implementation of Power grid Internet of Things (PIoT). An in-depth knowledge of the radio channel is vital to the application of wireless communication technologies in PIoT. This article investigates the radio channel measurements and characterization for PIoT substation scenarios. A novel channel sounder is designed for achieving omnidirectional measurements and phased array antennas-based directional measurements, and a directional multipath components extraction algorithm is proposed. The channel sounding system is verified and is used to perform a series of 3.35-GHz omnidirectional and directional channel measurements in four substation scenarios, involving a 10-kV switch room, a 110-kV GIS room, a semi-indoor 110-kV substation, and an outdoor 220-kV substation. Based on the measured channel impulse response data, both large-scale and small-scale fading characteristics of substation channels are extracted and analyzed. Empirical models of path loss, shadow fading, Rician $K$ -factor and root-mean-square (RMS) delay spread are proposed. In addition, results of RMS angle spread (AS) of departure and RMS AS of arrival are presented. These results will provide useful reference for the deployment and optimization of wireless communication networks in PIoT substation scenarios.