Sub-6GHz Channel Measurements and Modeling for City Underground Power Pipe Gallery

In complex scenarios such as underground power pipe gallery, for the access of terminal equipment e.g., massive sensors, various communication methods need to be applied to solve the problems of the breadth and flexibility of various services access. Due to the narrow and long feature of pipe gallery environment, the transmission characteristics and attenuation of wireless signals may be quite different from the results in existing researches. Special phenomena such as waveguide effects may occur, the transmission characteristics in different carrier frequency bands also have differences even if in the same environment. Therefore, the modeling of radio channel characteristics in underground pipe gallery is crucial for the design or optimization of communication systems. This paper studies the key radio channel characteristics of the frequency bands under 6GHz in the underground pipe gallery, such as path loss, delay spread, and shadow fading. The results show that the obtained channel characteristics are consistent with theoretical analysis in the actual environment. The obtained modeling results are of great significance to the design of the wireless communication system in the underground pipe galleries in the future.