5G

Verizon’s Ed Chan reflects on noise in the C-band neighborhood

 BARCELONA—Despite the headlines and the hassles associated with the C-band, Ed Chan, SVP and chief technology officer at Verizon, had some kind words for the Federal Aviation Administration (FAA).

“The FAA worked well with us along the way to kind of understand and do the testing,” he said on the sidelines of MWC 2023. “It went from a bit of fear mongering from some in the industry to a facts-based discussion.”

Chan was referring to the protracted fight between the aviation industry and the wireless carriers, backed by the FCC, over the deployment of C-band spectrum for 5G.

The FCC auctioned the spectrum with the intent that a 220 MHz guard band was sufficient to protect aviation users, but the FAA and airlines cried foul. In response, Verizon and AT&T agreed to temporary buffer zones around certain airports and limited power levels.

According to Chan, the airline industry didn’t straight up ask wireless carriers to pay for upgrading the airlines’ altimeters. The FAA estimated the cost of the upgrades was in the neighborhood of $26 million, although that was later challenged.

Either way, it sounds like peanuts compared to the $80 billion that wireless carriers spent to acquire the rights to use the spectrum via the C-band auction. Verizon itself spent $52.9 billion on C-band spectrum, including incentive payments and clearing costs.

Chan (politely) said there were “some inter-agency coordination issues” early on in the process, but in the end, a small number of older altimeters required new filtering technology and the FAA has done a good job in requiring the changes be made.  

From his perspective, it’s not really C-band alone that’s pertinent to the discussion. If the altimeters are susceptible to interference from sources outside their own spectrum band, then others outside the band could pose problems as well. It behooves everyone to update the filtering technology to basically “stay in your lane” so they’re not “listening” in other bands where they’re not supposed to be.

“It’s actually a good thing” that older technology is being updated, he said.

But it was still nothing short of spectacular that it even reached the level that it did. After all, there was that 220 MHz guard band that the FCC figured would be sufficient to protect anyone is the nearby vicinity.

“For us, it was quite amazing,” he said. “We are so far away – 200+ megahertz –  and still, somebody’s claiming interference. I’ve been in radio for 30 years, and that’s a long, long distance.”

It’s kind of like if someone living in a house complained about a noisy neighbor, but that neighbor happened to live two towns over, he said. “So maybe it’s not me being noisy. Maybe your ears are hearing a little bit too much in this case,” he quipped.  

From a pure technology perspective, it’s a receiver issue, he said. The FCC determined there was enough protection with the guard band, and “I think the FAA has been very clear … about putting the right filters in place so they’re not listening,” he said. “I’m glad we got that behind us.”

Verizon engineers have been busy putting C-band gear up on existing sites, in part in preparation for the next wave of C-band spectrum that becomes available late in 2023.

Frenzied buildout

Verizon is putting up C-band gear mostly on existing sites as opposed to new ones. It’s primarily a macro cell deployment, but small cells will show up a little more later this year, he said.

And it’s all Massive MIMO when it comes to Verizon’s C-band.

They could have deployed Massive MIMO on LTE, but it’s an antenna technology shift that’s happening at the same time as 5G. “If you do 5G without Massive MIMO, it’s not as big of an impact,” he said.

Samsung and Ericsson are supplying its C-band radios, which are all 200 MHz capable. When the rest of the spectrum becomes available, they essentially will flip a software switch.

Verizon expects to cover a population of about 200 million by the end of the first quarter with C-band. “Customers are really loving it,” he said.

Swing back to mmWave  

Verizon is focused on C-band right now, but when that deployment is over, it likely will turn to more millimeter wave (mmWave) again at some point.

“We see millimeter wave playing a significant role,” in super dense environments, said Srinivasa (Srini) Kalapala, VP, Global Technology and Supplier Strategy at Verizon. “It’s going to start playing an even more prominent role.”

Verizon was focused on mmWave before C-band came along and the pendulum is likely to swing back.

C-band, Chan said, is “like an easy button. Of course we’ll run there,” where it offers more capacity and better coverage than at the higher bands known as mmWave. C-band is at 3.7 GHz.

“That’s kind of why we shifted a lot of focus and investment on C-band first. Bigger bang for the buck. You go after those things when you have the opportunity… Once you run out of those opportunities, you go right to the next spectrum band,” he said.