Outdoor mmWave channel modeling for fixed wireless access at 60 GHz

The large bandwidths that are available at millimeter wave (mmWave) frequency bands allow high-throughput wireless communication systems that enable fixed wireless access (FWA) applications. In FWA networks, a stationary link is created between antennas installed at building facades or street furniture, such as lampposts. A Line-of-Sight (LOS) scenario is preferred, but to guarantee the quality of service to the user, communication should remain possible when the LOS path is obstructed. In this paper, outdoor channel models at 60 GHz are presented that can be used for the design and optimization of FWA networks, based on measurements with the Terragraph wireless system using IEEE Std. 802.11ad radios. LOS path loss measurement data is analyzed and building reflection loss, diffraction loss, and vegetation loss are measured. There is limited diffuse scattering, but reflections on the wall frame structure result in reflected paths with low losses. Existing vegetation models that are based on measurement campaigns at lower frequencies underestimate vegetation loss at mmWave frequencies, as measured excess attenuation values range from 15 to 25 dB for distances lower than 14 m. The presented channel models are used for link budget calculations for FWA networks.