Fiber is poised to play a key role in operator efforts to harden their networks against the effects of climate change, with representatives from AT&T, Verizon and Consolidated Communications highlighting its resilience in windy, wet and warm weather conditions.
The U.N.’s World Meteorological Organization released a report in August 2021 which found the number of weather-related disasters – including storms, floods, fires and extreme temperature incidents – has increased by a factor of five over the past 50 years. It attributed the rise to both climate change and improved reporting.
Consolidated CTO Tom White told Fierce operators in the U.S., especially those like itself with infrastructure distributed across the country, face a wide range of threats. “Hurricanes, storms, fires, ice, you name it,” he said. “It’s been top of mind for us for many years as we’re building our networks to really think about not just the technology we’re deploying but how we focus on redundancy, survivability.”
AT&T EVP of Technology Operations Chris Sambar said that like Consolidated it has been focused on building resilience into its network for some time. He noted that it really homed in on hardening its network after winning a contract from the U.S. government to deploy a wireless network for first responders in 2017, and doubled down after one of its facilities in Nashville was bombed in late 2020.
Flooding, fire and frost
Karen Schulz, a Verizon spokesperson, said the operator has seen “some changes in weather patterns over recent years including an increase in wildfires, extended hurricane season and unseasonable ice storms.” When compared to copper or coax cables, she said fiber is better at handling all of these. That’s because it’s lighter and more flexible and not subject to water or electrical interference.
AT&T’s Sambar agreed. “If it’s metal you’ve got a problem when it comes to rain and flooding and water damage,” he said. He recounted an incident in which a manhole flooded due to excessive rain but the fiber lines running through it were unaffected. “If that had been copper in there or HFC, we would have had a big issue. So, the faster we can get the copper out of our network and get the fiber into the network the better off we are,” he noted.
Sambar said the operator’s Climate Change Tool (CCAT) has been key in helping it pinpoint potential problem areas where infrastructure is vulnerable to weather-related threats. Launched in 2019 in collaboration with the U.S. Department of Energy's Argonne National Laboratory, the modeling tool initially covered only four states, but was expanded in 2020 to span the entire contiguous U.S. The CCAT has helped AT&T identify central offices and other facilities where it has transport equipment in basement areas which might be prone to water damage and flooding in the future, Sambar said.
“When we put that stuff there 50 or 60 years ago maybe that was an area that never flooded so we never worried about it,” he explained. “Well, things are changing now unfortunately with the climate.”
Sambar, Schulz and White all said they use a combination of aerial and underground lines in their networks, deploying the latter particularly in areas which are prone to high winds. However, White noted there are certain areas, such as in New England, where it’s just not possible to bury cabling. Even in aerial deployments, though, fiber outperforms copper when it comes to severe weather, he said.
“Fiber is lighter, it doesn’t have as much weight load on the pole lines. And so, if you do have weather impacts, removing that heavy copper reduces the weight on the poles, which we have seen will survive better,” he said. This holds true for both wind and ice-related events, White added.
Even looking at fire-related events, White said “glass tends to do better” even though both fiber and copper are susceptible to melting.
Power up
Fiber aside, there are other things to think about when it comes to planning for climate change. For instance, all three operator representatives indicated securing a secondary power supply is critical to preparing the network for severe weather events and natural disasters.
“Power has actually been one of the biggest challenges. Even in extreme heat, you’ll see Texas has struggled over the years with their power grids and they’ll have planned brownouts,” White explained. “And so, we’ve built tools in the background. We’ve expanded our battery backup powers, we’ve added additional generators and as I mentioned earlier we’re really looking at the solar opportunities for a lot of these locations” to ensure a steady source of electricity.
Sambar said AT&T also uses generators as a backup power source, adhering to an “N+1” motto. That is, it always has one more generator on hand than it actually needs to keep a site running – just in case. It also adheres to strict maintenance schedules to keep those generators fit by “exercising” them, which entails getting them running and switching all power for a given site over to the backup supply for a certain amount of time.
He added AT&T works closely with municipalities to ensure it’s near the top of the list to have its primary power restored when disasters occur. “This is kind of the boring mundane stuff that we do everyday,” Sambar joked.
Other measures
Among the other steps it takes to protect its network, Schulz said Verizon engages in landscape mitigation activities to “eliminate brush, trees or other debris” that could burn in areas that are prone to fires. In regions where extreme cold is possible, it buries its fiber deeper underground to help mitigate the effects of deep freezing, she added.
White said in places like Texas, Consolidated has started putting a cover with reflective paint (which it calls a sail) on its outdoor equipment to help keep network nodes cool. In some instances, it also refits its cabinets with air-conditioned doors.
“We have alarming within all of our locations for temperatures. And we have seen the temperatures over the years…where we get in the warning areas on a more regular basis,” he said. “So, it’s become pretty much a standard for us now that we’re putting the sail over top of one and in a certain size one we’ll go ahead and proactively put the door on it just to be sure.”