WASHINGTON, D.C. — Google is using its involvement in the 3.5 GHz Citizens Broadband Radio Service (CBRS) spectrum to advocate for a new way to divvy up spectrum for 5G that encourages shared infrastructure and shared spectrum, and fosters new business models.
The company is a key member of the CBRS Alliance, which also includes all four major U.S. operators AT&T, Verizon, Sprint, and T-Mobile US; and cable heavyweights Comcast and Charter. The goal of the group is to enable others to use the 3.5 GHz band without creating interference. That band is currently being used by military and satellite incumbents when needed, but frees up the spectrum for commercial use at all other times.
Speaking at the DC5G conference this week, Preston Marshall, principal wireless architect at Google and engineering director at Alphabet Access, said that Google believes that the existing spectrum licensing model is focused on exclusivity making it nearly impossible for new players to enter the market. “Cellular is built around the outdoors. We have gone through four generations with a similar model that includes exclusive spectrum, exclusive backhaul, and the assumption that the Layer 1 of the network was the most important.”
Instead, Marshall is advocating that FCC officials consider another model that he calls a “use it or share it” model, in which there are different access rights to the spectrum within the same band. In this model, if a licensee launches a service with a radio in the spectrum band, that band is protected from interference from others. But if a licensee doesn’t launch a service, others can use that spectrum. “If we had different access rights within the same band, it would fundamentally change how we deploy 5G,” he said.
Of course, Google’s incentive behind its work in spectrum is to secure “abundant bandwidth for everyone,” Marshall said.
If the FCC were to allow more shared use spectrum models, Marshall believes that it would open the door to enterprises. For example, he believes that a company like Marriott could use licensed spectrum to outfit one of its hotel properties with LTE or 5G and then sell capacity in its hotel back to operators like Verizon or AT&T. “A Marriott could deploy technology just like Verizon,” he said, noting that this model would encourage a denser network. Another model might be for a Starbucks (which currently offers WiFi to its patrons) to deploy 5G and offer 5G services to its customers. “We want to make it advantageous for building owners to do more. That’s why a neutral host is fundamental to 5G.”
Managing Shared Spectrum
But Marshall admits that managing shared spectrum in a neutral host environment could be a big challenge. There would have to be a way to negate any potential interference. In addition, devices in that spectrum band would have to be able to work on different radios in case one licensee would decide to deploy WiFi and another might deploy 5G or even 4G. “If you believe deployment will be shared then the bands in the handset will also have to be accessible,” he said.