Will my phone work during and after the storm?

A majority of U.S. homes now rely solely on a cellphone, according to a report released earlier this summer by the Centers for Disease Control. And increasingly, those who do have land lines — at work and at home — use VOIP services that deliver phone access via the internet.

So what happens if Irma hits South Florida?

AT&T, Verizon and Sprint say their towers and antennae systems are built to withstand significant wind and flood risks, that their switching centers have been hardened and that permanent and backup generators will kick on when power goes out. In the event a tower or antennae system is compromised, causing an outage in a particular area, their mobile armies of COWs (Cell on Wheels) and COLTS (Cell on Light Trucks) can be moved in to provide temporary service until service is repaired.

Can a cell tower sustain a category 4 or 5 hurricane? Absolutely, said Sprint spokeswoman Roni Singleton. “The local building codes dictate how strong cellular towers must be for a given area. There are a lot of variables that impact the code, so there isn’t a simple one size fits all answer, but the codes for Florida are pretty strict. While we do occasionally have equipment damaged on towers due to high winds — generally antennas — it is extremely rare for a tower to have structural failure.”

The vast majority of storm-related site outages and impairments are due to loss of power or backhaul telecommunications, she said. Cell companies are mitigating those potential issues with redundancies in their systems, refueling of generators and more backup portable generators at the sites.

AT&T, for instance, said some of its diesel gas tanks used for refueling generators can float. Some of its generators are fueled by natural gas, so they won’t need to be refueled. “We have taken steps, where possible, to locate switches and generators critical to network operations to upper floors of buildings in case of flooding,” said spokeswoman Kelly Starling. AT&T’s network fared well in Hurricane Harvey, a Cat 4 storm, she noted. But no wireless network is 100 percent hurricane proof.

“We’ve worked for the past few days to position equipment and crews to respond to the storm. We’re closely linked with Florida public officials in their storm response efforts. With a storm of this size, we may have some outages. But if service goes down, we'll do all we can to get it back up as fast as possible,” said Joe York, AT&T Florida president, in a statement.

Verizon’s network “super-switch” processing centers in Florida are designed to withstand Category 5 hurricanes, said spokeswoman Kate Jay. These facilities — which handle tens of millions of calls and connections even on a crisis-free day — feature hardened shells, large-scale on-site power generation and other back-up systems.

In addition, the company has put cell site equipment on stilts to avoid damage caused by flooding and has installed new in-building network systems at hospitals, government and emergency facilities, high-traffic public venues and other key locations, Jay said.

Sprint is standing ready to deploy incident management teams, as needed, to assess impacted areas, inspect local wireless networks, and make any repairs after the event, Singleton said. “Strike teams are prepared to go in to act fast.”

But what if you’ve got phone service over the internet?

If your phone service is part of a Voice-over-Internet Protocol (VOIP) package with AT&T or Comcast’s Xfinity, you are receiving phone service via the internet. The service can be interrupted as a result of downed cables, and the service will not function until those facilities are restored. Because of this, the carriers recommend customers also have a mobile phone.

Xfinity consumers can purchase a back-up battery for their modems so they are still able to make phone calls for several hours during the power outages that are common after hurricanes. A call-forwarding feature also is available, which will forward calls to your mobile should you lose power. Comcast recommends you forward your calls to your mobile phone before a severe storm knocks out power.

If you are part of the minority of South Florida residents who still have a traditional landline in your home, you have another option for service after the storm. While strong storms can knock down telephone lines atop poles, there is more potential for a power outage to interfere with wireless operations than with landlines, Starling said.

Nancy Dahlberg: 305-376-3595; @ndahlberg. This article has been updated.


▪  During an emergency situation, text messages may go through more quickly than voice calls because they require fewer network resources.

▪  Be prepared for high call volume. The increased calling volume may create network congestion, leading to “fast busy” signals on your wireless phone or a slow dial tone on your landline phone. If this happens, hang up, wait several seconds and then try the call again. This allows your original call data to clear the network before you try again.

▪  Keep non-emergency calls to a minimum, and limit your calls to the most important ones. If there is severe weather, chances are many people will be trying to place calls to loved ones, friends and colleagues.