Wireless Backhaul for 5G Highest Use for 70/80/90 GHz, FCC Told
Rules for the 70/80/90 GHz bands should be optimized for wireless backhaul and compatible applications, said T-Mobile and other carriers in comments posted Thursday in docket 20-133, in response to a June NPRM (see 2008050058). Others sought broader use.
“Require all registrants to certify that their registered links are constructed as required,” T-Mobile said: “The Commission should not, however, adopt the currently-formulated proposals for maritime and aviation use of the spectrum, which may potentially limit use of the bands for backhaul operations.”
CTIA noted terrestrial licensees have used the bands since service rules were adopted in 2003 “for important fixed services, especially backhaul.” The densification required by 5G networks, “especially in the millimeter wave bands, has dramatically increased the need for reliable backhaul solutions,” CTIA said: “Fiber may not be available in the deployment area, but may be located only a short distance away from the 5G base station. Wireless backhaul devices can be used to provide connectivity and transport for 5G services where wired backhaul is not available.” The Competitive Carriers Association also said the bands are important for wireless backhaul: “Outdated licensing rules regulating the 70/80/90 GHz bands bar many potential band users and leave much of the spectrum in these bands completely unused.”
AT&T said it has a nationwide license to operate in the bands, and “registers, builds, and operates links under that license for cell site backhaul.” Relaxing the antenna standards “by modifying the maximum beamwidth, minimum antenna gain, and co-polar and cross-polar discrimination requirements would increase the uses of the 70/80/90 GHz bands by allowing for smaller antennas,” the telco commented. “The existing regulatory framework governing the 70 GHz and 80 GHz bands is overly restrictive and ill-suited to supporting the bands’ highest and best use -- the provision of fixed wireless 5G backhaul” and the commission’s proposals “will provide more flexibility for fixed use,” Verizon said.
The Wireless ISP Association said members use 70 and 80 GHz “as a licensed counterpart to unlicensed spectrum in the 60 GHz band.” WISPA supports “many of the reforms proposed in the NPRM so long as they are implemented consistent with the critical principles the Commission has endorsed: (1) protecting incumbent users, and (2) maximizing the flexibility of the band to allow other uses that are compatible with the proposed operations.”
Alphabet's Loon, which offers balloon-powered internet access, asked for room for stratospheric services. “In light of the ongoing pandemic, economic crisis, and the predicted above-normal Atlantic hurricane season … the Commission should ensure that this proceeding incorporates the widest possible set of use cases into its existing framework, including those focused on closing the digital divide and enabling disaster preparedness,” Loon said. “The propagation characteristics …, general compatibility with existing allocations and terrestrial uses, and the large bandwidths available in the 70/80 GHz Bands make the band highly suited for large feeder links for airborne platforms,” agreed Elefante Group. It's developing a geostationary, lighter-than-air communications platform in the stratosphere.
Moog, which offers an airport runway surveillance system using 90 GHz spectrum, said the rules must protect incumbents. “The co-existence of multiple types of systems in the 90 GHz Band is possible with proper planning and putting the proper measures in place,” Moog said.
“Adopt a comprehensive, technology-neutral approach to managing static and moving point-to-point links in the 70/80 GHz bands, and … set a path toward a dynamic spectrum access model,” the Dynamic Spectrum Alliance recommended. “Prioritize the amendment of … antenna rules in the 70/80 GHz bands, thereby allowing smaller antennas,” the Fixed Wireless Communications Coalition said: “Adopt a channel plan for the 70/80 GHz bands based on the ITU band plan detailed in Recommendation ITU-R F.2006, and … require licensees to certify the construction of registered links prior to the expiration of the link’s construction deadline.”