Path Loss Characterization of 7-GHz Terrestrial Propagation Channel in Urban Environment

To satisfy dramatic increasing data demand, sharing spectrum for Wireless Local Area Networks (WLAN) is being considered. Two bands at 7 GHz (6875 - 7125 MHz) and 13 GHz (12700 - 13250 MHz) are currently allocated to point-to-point links, mobile links and fixed-satellite service. The analysis of potential interference between these incumbent services and WLAN devices is the ultimate purpose of this paper. Few path loss studies have been done in these bands and they only estimate attenuation through some materials and do not develop empirical propagation models at these frequencies. Narrowband drive tests with a moving receiver and fixed high-raised transmitter were conducted at both 7 and 13 GHz. This paper reports measurement results at 7 GHz in an urban environment with flat terrain, and corresponding log-distance path loss model. The measured results are compared with existing deterministic and statistical path loss models. We compare different terrain and clutter resolutions used in the deterministic model with respect to prediction error. Analysis of 7-GHz results for other scenarios and 13-GHz results will be reported in the near future. This work will provide useful guidelines for future coexistence studies in these bands.