Verizon recently completed a proof of concept that could allow the carrier to tap into its vast millimeter-wave (mmWave) spectrum holdings, owned fiber assets and its Intelligent Edge network architecture to power broadband services.

The test beamed a signal using licensed mmWave spectrum in the 37 GHz–39 GHz band between a centralized, rooftop radio site and a radio sitting on a simulated building. That signal was then transmitted through coaxial cable throughout the building to a data processing unit tied to a modem, which then used the building’s existing wiring to transport a broadband signal to end-user routers.

This architecture used a “simplified broadband network gateway” instead of Verizon’s 4G LTE and 5G wireless cores to direct the traffic over Verizon’s public IP network to the internet. The carrier noted “this means the data traffic will not add load on Verizon’s current wireless cores while at the same time providing excellent capacity and latency.”

This test model differs from traditional fixed-wireless access (FWA) services that use licensed spectrum to beam a broadband signal to receiving routers within a building. That traditional FWA model runs through a carrier’s core network and is basically a wireless broadband extension of their current 4G LTE or 5G network.

Verizon states that this newly tested model also reduces the cost of providing broadband connectivity to multiple locations within a building.

“Depending on the various designs of buildings, office complexes and campuses, running fiber connections to individual buildings and individual units within buildings requires complex licensing, significant capital investments, long lead times and can be disruptive, making air links and established indoor cabling appealing alternatives for delivering services,” the carrier noted in a press release.

“Applications for this type of point-to-multipoint mmWave-based technology could include distributed enterprise campuses, commerce areas, home broadband for multi-dwelling units or other areas where air links could easily connect donor sites in the radio access network (RAN) to facilities with their own internal infrastructure.”

Adam Koeppe, SVP of technology planning at Verizon, noted in a statement that the carrier could use this model across a large chunk of its footprint.

“Leveraging our significant fiber footprint in over 70 major markets nationwide and large amounts of ready-to-use mmWave spectrum, this new architecture means we will be able to provide point-to-multipoint architecture in a cost-effective and efficient way,” Koeppe explained.

The carrier added that it’s completing requests for proposals (RFPs) for the necessary radio access equipment used in the test and “expects to continue developing this technology throughout the year.”

Operators have struggled to find a compelling use case for their extensive mmWave spectrum holdings. Jennifer Fritzsche, managing director at Greenhill and Company, noted in a blog post via analyst firm iGR that AT&T has an average of 1,040-megahertz of nationwide mmWave spectrum and Verizon controls 2,024-megahertz of mmWave spectrum nationwide.

However, the challenge with mmWave spectrum is that it has very limited propagation characteristics compared to low- (sub-2 GHz) and mid-band (2 GHz to 10 GHz) spectrum. This includes issues with mmWave spectrum penetrating walls and being blocked by foliage.

“Millimeter wave has arguably gone down as one of the greatest failures in the wireless world in recent memory,” Dan Hays, partner at PwC, said in an interview with SDxCentral during the recent MWC Barcelona 2023 event. “There was a lot of wishful thinking. And, to be fair, there have been advances in radio technology and massive [multiple-input/multiple-output] that cures a lot of things. But it only goes so far with the laws of physics.”

Jeff Wang, global 5G and networks lead at Accenture, noted in an interview with SDxCentral late last year that those higher spectrum bands are also going to force a complete rethink of deployment models to take into account their more challenging propagation characteristics.

“Accenture is working constantly with clients on how do we deploy this because that density is not easy economically,” Wang said.

As an example, he noted that if a sub-1 GHz-based network required 50,000 cell sites to cover the U.S., using sub-6 GHz, which many operators are rolling out as part of their highly touted mid-band updates, or millimeter wave (mmWave) will need hundreds of thousands of sites.

Kyle Malady, EVP and president of global networks and technology at Verizon, recently stated the carrier has deployed more than 40,000 nodes beaming out mmWave spectrum.

“Now that millimeter-wave technology turns into a tool for RF engineers to use in hot spots that they have,” Malady said.

Verizon has also touted the use of its mmWave spectrum holdings to power private 5G deployments. The carrier earlier this year also aggregated 20 megahertz of “LTE” spectrum and 400 megahertz of 28 GHz spectrum that resulted in upload speeds up to 1.26 Gb/s.

AT&T is less enamored with mmWave spectrum and has only used it modestly in deployments.

“What we found is propagation off of millimeter-wave towers is so short,” Chris Sambar, EVP of AT&T network, recently explained. “That’s a very difficult value proposition to make work, so we are focused on serving it with our mid-band rollout spectrum.”

AT&T did use those assets as part of its initial 5G deployment, similar to Verizon but, also like Verizon, those efforts have since been overshadowed by its better-propagating C-band spectrum holdings.