Spectrum Sharing Between WLANs and Fixed Microwave Links in 6 and 13 GHz Bands: a Case Study

The 6 GHz band (5925-7125 MHz) has recently been proposed by the FCC to be shared with unlicensed devices This band is allocated to fixed, mobile (temporary fixed) and fixed satellite service links. The 13 GHz band (12700-13250 MHz) could also be subject to more flexible use, considering that it is allocated to the same type of incumbents. The purpose of this paper is to analyze coexistence between Wireless Local Area Networks (WLANs) and current terrestrial fixed links in these bands based on a case study approach, which can be replicated to other parts of the country. The coexistence analysis uses information from real links and accounts for the terrain morphology and actual land use to calculate the potential interference. We have conducted interference simulations from low-power indoor (LPI) WLANs to terrestrial fixed links and vice versa, from terrestrial fixed links to LPI WLANs, in the Denver metro area. The simulations have been performed in the upper part of the 6 GHz band, from 6875 to 7125 MHz, designated as the U-NII-8 band by the FCC, and in the 13 GHz band. To validate the simulations, we measured the incumbent signal power detected on the ground in a few locations in this area. We found that terrestrial fixed links operating in these bands can coexist with LPI WLANs without significant interference between each other, which will benefit consumers and encourage technology and innovation.