Google, an early and well-known proponent of sharing in the 3.5 GHz CBRS space, is seeing strong demand for the General Authorized Access (GAA), or unlicensed, part of the band, with deployments doubling from March to April.
In CBRS lingo, CBSDs refer to Citizens Broadband Radio Service Devices, which may include access points or small cells. During the March to April time frame, across the industry, the CBRS ecosystem consisted of 17 CBSD vendors, 48 different FCC-certified CBSD models, 70 different FCC-certified end user devices and modules, and more than 1,250 Certified Professional Installers (CPIs). Google's Spectrum Access System (SAS) supported all of the hardware and Google helped train a large fraction of the CPIs.
“We are very pleased with the growth in deployments and the ecosystem at large,” said Google Engineering Director Preston Marshall, who wrote the book on three-tiered shared spectrum and was one of the participants in the Fierce CBRS week of virtual panels.
Mention CBRS and the types of venues where it may be used – stadiums, campuses, airports – and the question immediately arises whether it’s going to invade Wi-Fi’s turf. That came up during the development days of the CBRS ecosystem and continues to this day.
Like a lot of players in the CBRS ecosystem, Google views CBRS as complementary to Wi-Fi, not a replacement. Customer demand arises where applications can benefit from features of LTE and CBRS mid-band, where Wi-Fi struggles to deliver under certain conditions, such as mobility.
“We take mobility for granted, but hand-overs are a hard problem and LTE is a proven solution,” Marshall told FierceWireless via email. “We see demand in places where robots and autonomous vehicles need to move around, like in warehouses, distribution centers, or agricultural fields. Those devices need to maintain connectivity at all times.”
In terms of quality of service (QoS), Wi-Fi can get noisy and isn’t designed to handle QoS the way LTE is, so it’s helpful to put some applications on a separate CBRS LTE network, he said.
Examples where Google sees demand are applications in factory settings where even small amounts of downtime can be very costly and where safety is a factor. For example, a factory might need to immediately turn off a robot in a hazardous situation. Or, a job like remote video monitoring might be done more effectively with LTE.
CBRS also covers a wider area with fewer radios than a Wi-Fi system. If a business needs to cover a distribution center spanning many football fields or acres of farmland, CBRS will do the job. And in terms of control and security, CBRS lets enterprises take control and put radios where they’re needed without having to depend on a third party.
“LTE admission control gives enterprises absolute control over who and what gets on their network, since every device needs to authenticate with a SIM,” he said.
Google offers a suite of services and is certified as a Spectrum Access System (SAS) administrator; the system includes an ESC network to manage fundamental access to spectrum. It also offers online network planning and online training and certification via Coursera for those who want to become a CPI.
While the GAA portion of the CBRS band is being used for commercial purposes now, anticipation is building for the Priority Access License (PAL) auction set to commence on July 23.
According to Marshall, for many enterprises, it may not make sense to bid on a county-wide license, and the GAA will suffice. Where PALs get more interesting for enterprises is sub-leasing, where a company might want a higher guarantee of spectrum availability for the long term, but only needs it for a small geographical footprint.