Google seeks temporary license for 27.9-28 GHz experiments

Once again, Google (NASDAQ: GOOG) is asking the FCC for an experimental license so that it can conduct highly secretive experiments, this time in the 28 and 31 GHz bands, in northern California.

By design, it's impossible to determine from the company's highly redacted filing what exactly it intends to do in the spectrum. However, Google spelled out how its tests will not adversely impact any authorized users of RF spectrum in the bands and appears to have ascertained the necessary frequency coordination with other spectrum users.

"While most of Google's testing will use wideband transmissions, Google also seeks authorization to conduct limited narrowband testing in the 31 GHz band," the filing stated. "Narrowband testing is expected to take place over no more than 12 hours during the pendency" of the special temporary authority (STA).

Based on technical specs listed in the filing, it appears that the experiments are terrestrial in nature and will be in a relatively confined area using relatively low power, Tim Farrar, president at TMF Associates, told FierceWirelessTech.

A lot of people are interested in exploring 5G technologies in the higher frequency bands. Exactly what Google plans to do is unclear, but it doesn't' appear to be related to drones or Project Loon balloons, although that's not to say that it couldn't evolve into something related to those types of applications in the future, he noted.

It's also not clear whether it's for a fixed or mobile application. In its application, Google said its "tests/experiments represent a 'secret commercially valuable plan' within the meaning of a trade secret as recognized by the Commission." The services and technologies subject to the STA have "not yet been fully developed but are expected to lead to material developments in markets subject to competition from multiple U.S. and non-U.S. third parties."

Millimeter wave researchers, including Ted Rappaport, director of NYU Wireless, which has conducted pioneering measurements and channel model research at 28 GHz, 38 GHz, 60 GHz and 73 GHz, were pleased when the FCC last month decided to propose new rules for four different bands of high-band spectrum above 24 GHz designed to lay the foundation for 5G networks in the U.S. That included the 27.5 to 28.35 GHz, also known as the 28 GHz band; the 37 to 38.6 GHz band, also known as the 37 GHz band; from 38.6 to 40 GHz, known as the 39 GHz band; and the 64-71 GHz band.

Many people didn't believe the higher spectrum would ever be viable for mobile communications, yet NYU Wireless has been focused on millimeter wave research the last few years. Rappaport himself has been involved in millimeter wave technology research for two decades.

Rappaport said millimeter wave frequencies will be more efficient because the antenna will be designed to be much more focused than it is today. He has described it as if every phone will have its own megaphone, rather than distributing RF all over at every angle.

For more:
- see this filing and this filing

Related articles:
AT&T seeks experimental license for technology in 3.5 GHz region
Millimeter wave researchers praise FCC's move to unleash more spectrum at higher bands
Google applies for experimental 3.5 GHz license in Kansas City
Google plans mystery experiments at 76-77 GHz