900 MHz Private LTE Important to Utilities; Bandwidth Limited
Advanced communications allowed by 900 MHz spectrum cleared by the FCC for broadband 5-0 in May (see 2005130057) will be only one part of the answer for electric utilities as they move toward smarter grids, speakers said during a panel Monday at NARUC. The FCC approved 6 MHz in the band for broadband, reserving 4 MHz for narrowband.
“The role of advanced communications infrastructure is crucial for operation of the power grid, as well as enabling different types of technologies and integration of distributed energy sources,” said Shay Bahramirad, ComEd vice president-engineering and smart grid. Utilities face challenges from climate change-related outages and COVID-19 demands, she said. Customers demand a higher level of reliability and resiliency, she said: “Grid transformation is a necessity to mitigate threats and improve services.”
The 900 MHz alone isn’t enough, Bahramirad said. Fiber will provide the “backbone” connecting stations and distribution equipment “supplemented by wireless for the last mile,” she said. Even private LTE networks like those in the band aren't a substitute for fiber, she said. Private LTE will allow utilities to consolidate networks, reduce the complexity of their operations and cut costs, she said.
Utilities can already monitor their networks wirelessly, said David Wells, U.S. Department of Energy senior adviser. “The problem is you couldn’t control the latency,” he said. “Whenever you’re operating a system, you have to know when that information is going to get from point A to point B,” he said: “That’s how you’re to rely on doing grid command and control.” Private LTE means more security, Wells said: “Now you own your own network. You’re able to now control your own bandwidth. You can control the security.”
Wireless can also be used to replace fiber during emergencies since wire is subject to wildfires and other disasters, Wells said. “Now you’ve built in a whole new reliability you didn’t have before,” he said. Wells noted the private LTE network can’t be used for everything and is subject to overload. “You don’t want to send every piece of data back across your LTE network to get to your control center,” he said. “It’s not that much bandwidth.”
“First and foremost for the utility is the necessity to put as much security into the critical elements” of the network “as it becomes more and more dependent on distributed generation and to make sure that it’s not vulnerable as connection to the internet often is,” said Morgan O’Brien, executive chairman of Anterix. He's a lead proponent of the changes for the band approved by the FCC.
The private LTE networks can help close the digital divide, O’Brien said. Utilities will install towers, backhaul and other infrastructure that will be shared with rural broadband, he said. The amount of spectrum for LTE in the band “is large in some contexts but very small in others,” he said. “It has to be husbanded for the very crucial elements” but the infrastructure could be shared, he said. “It’s a balancing act,” he said: “This is a new capability that the FCC has given the industry, a new opportunity.” Fiber still “has to do the heavy lifting,” he said.
“We are all sort of living with the limits of the current technology and how it is impacting our ability to do the jobs we need to do,” said Elin Katz, managing director-utilities at consultant Tilson. The pandemic highlighted communications shortfalls, she said: “There’s a lot of pressure that I’ve seen on commissioners and utilities to do something.” It’s important to ask not only the cost of new technologies but the cost of not investing, she said.