Preston Marshall is chief wireless architect for Google, and he’s also been a big advocate for CBRS. Marshall chairs the Wireless Innovation Forum (WINN Forum) as well as the CBRS Alliance board. On a recent Competitive Carriers Association webinar, Marshall said CBRS was created to make spectrum a more accessible resource and open up new business opportunities for its use.
He laid out the top expected use cases for CBRS spectrum, saying operator mobility offload is “certainly the base case.” And the prospect of mobility offload was compelling enough to the Tier 1 carriers in the United States that they caused the handset ecosystem to support the band.
“We have several of the Tier 1 operators going for that [CBRS]. It’s ideally suited for them because it’s an offload network, it doesn’t have to have 100% reliability or nationwide coverage,” said Marshall.
Both Charter and Comcast have expressed interest in CBRS to offload some of their MVNO traffic from Verizon’s network. Marshall said the operator usage of the CBRS band will likely use a mix of technologies from LTE, to 5G non-standalone, to 5G standalone.
The next use case for CBRS is neutral host mobility where a third-party builds capacity, which can be accessed by the other carriers or MVNOs. Marshall said this use case is made possible “because for the first time, we have one piece of spectrum that’s accessible to every single carrier,” and it provides “an opportunity to create a new kind of ecosystem where we have a single network shared across operators.”
There is no public adoption of neutral-host mobility, yet, but Marshall said there’s a lot of discussion happening. He said wherever there are expensive deployments of fiber and/or Wi-Fi, it would be relatively inexpensive for a neutral host to add CBRS capability in those places.
A third big use case for CBRS is private LTE/5G, which has gotten a lot of interest, both from enterprises as well as by traditional operators, looking at a new marketplace alongside Wi-Fi. Private LTE will provide mobile wireless within a campus with local breakout of traffic rather than having it go back to carriers. It can offer better security than Wi-Fi and operate within a firewall. Marshall said at least one Tier 1 carrier has shown a lot of interest in providing private LTE-as-a-service that it would manage through its own infrastructure. He did caution that the private wireless ecosystem is somewhat dependent on the handset ecosystem expanding.
Enterprises are also looking to bid on CBRS so that they can build private wireless networks for their venues, office campuses or manufacturing and industrial environments.
A fourth use case for CBRS would be a transition for wireless internet service providers (WISPs) that are migrating over to CBRS. Marshall sees a massive migration from Part 90 legacy equipment to Part 96 CBRS equipment for WISPs. This will move WISPs into the 3GPP technology ecosystem. “It opens up the use of the same radio network and puts the wireless broadband industry essentially on the same path as the carrier 5G technology,” said Marshall. “I think this is a real opportunity to create a much more hybrid service than the stove-pipe that exists between fixed wireless and MNO operations today.”
In conclusion, Marshall, who is an unabashed champion of CBRS, said this is the first opportunity for interested parties to provide carrier-grade technology “without the spectrum gauntlet.” CBRS provides a premiere piece of mid-band spectrum to build networks.