California’s recent power shut-offs, meant to reduce the risk of potentially catastrophic fires, have had an unwelcome side effect. The blackouts have also cut power to many cellphone towers, blocking the main communications source for many in harm’s way.
“You don’t appreciate how essential cellphone service is until you lose it,” said Chris Ungson, deputy director for communications and water policy for the California Public Advocates Office, an independent agency within the state’s Public Utilities Commission. “It’s not just a matter of inconvenience; it’s a matter of public health and safety. It’s a lifeline to many, many people.”
Emergency calls to 911 are one indicator: The Governor’s Office of Emergency Services said more than 80 percent of such calls in California last year were made by cellphone.
For years, state and federal regulators have pressed the cellular companies to better reinforce their networks for emergencies. The Federal Communications Commission said Monday that it was conducting “a comprehensive review of the wireless industry’s voluntary commitment to promote resilient wireless communications during disasters.”
The F.C.C. wrote to cellular carriers last month to express concern about service reliability as California’s wildfire season neared, asking for an account of steps being taken “to promote the continuity of communications for public safety officials and residents.”
Verizon, AT&T and other carriers said Monday that they were working to minimize disruption, but could offer no specific guarantees.
In Paradise, a Sierra foothill town rebuilding after it was devastated by fire last year, the combination of the power shut-off and uncertain communications was causing renewed anxiety on Monday.
Jess Mercer, who conducted her elementary-school drawing class by lantern light, said cellular service was spotty and wireless internet connections were out in many areas, leaving many parents and teachers uncertain about whether school was open.
Some parents, she said, were resorting to a 20th-century information source to stay updated. “A lot of people are telling me they’re getting into their cars and trying to get warm with their heaters, and they’re listening to the radio,” Ms. Mercer said. “People are trying any way they can to get information.”
In Sonoma County, where a major fire led to the evacuation of 180,000 residents over the weekend, one-quarter of the 436 cellphone towers were not functioning, the F.C.C. said Monday.
In nearby Marin County, more than half of the 280 towers were out of service. Most of the outages were related to the pre-emptive power cuts imposed by Pacific Gas & Electric, the state’s largest utility.
The increasing connection between power failures and communications outages arises from the transformative effect of wireless devices, which many people have made their sole source of telephone service.
Most cell towers have some form of backup power. When they lose power, they resort to batteries. If the batteries run out, the towers draw power from generators, which rely on fuel. These methods can provide power for days or longer, depending on whether the generators can be refueled.
AT&T said all of its cell sites in California had some form of backup power. Verizon said most of its towers were equipped with batteries and generators. T-Mobile said it had built-in generators in its most critical sites, while others had batteries. Sprint said that some of its cell sites had built-in generators, and that it was deploying portable generators for others as quickly as possible.
“Providers invest significant resources to strengthen and harden networks so that they are able to maintain service during emergencies,” said a statement from CTIA, the wireless industry trade group.
There are limits to what carriers can do when the blackout is accompanied by wildfire. Some generators are inaccessible because of the fires and can’t be refueled. In other cases, sites lack generators because of zoning restrictions.
In 2007, after Hurricane Katrina, the F.C.C. ordered cellular companies to provide at least eight hours of backup support for their towers. But the Office of Management and Budget rejected the move on procedural grounds, and the commission dropped the plan.
In May, the California Public Advocates Office called on the Public Utilities Commission to exercise emergency powers to ensure that communications systems continue to operate in emergencies. It asked the commission to immediately order cellular companies provide backup generators and alternate routes in high-fire areas and flood plains.
“The failure of our communications systems in emergencies is a life-or-death matter, and one that must be addressed immediately,” the office wrote.
The commission directed the wireless providers to report how they were hardening their systems, but the Public Advocates Office said the responses were vague and ambiguous.
“There is a constant pushback from the utilities,” said Ana Maria Johnson, program manager at the Public Advocates Office. “They want to voluntarily do things. It has to be requirement that they do this. It is critical that wireless facilities have on-site backup power.”
To some extent, the Public Utilities Commission has put the responsibility on the public. In a recent report, it noted that wireless customers “may or may not have voice service in a power outage, depending on the backup power installed at cell sites,” and said the commission “does not have rules mandating backup power for this type of service.”
It added that it was “the responsibility of the customer to obtain the required backup power in the residence to have working telephone service during an outage event.”