As a kid growing up in Guam, Thomas Bernardo remembers going downtown to make a call to the mainland United States. The cost: $14 a minute. With that, you often also got plenty of static.

“Today, I can make VoIP calls for no cost, and it’s crystal clear,” he said. And he’s part of the team that makes it possible.

For the past 22 years, Thomas has watched technology transform our industry, all from thousands of miles offshore. He started as an operator in our Guam undersea cable landing station, and now helps manage it.

The Guam station is one of 16 strategically placed stations that maintain our undersea cable operations. Some terminate or originate signals. Guam is one of several that act as transit stations. In that role, they connect two or more cables so information can move to its final destination.

“The improvements we’ve seen in our ability to make calls have been tremendous,” he said. “When I started, we were still using coaxial cable, but we soon moved to high-speed fiber optics. We just finished an upgrade to 40 Gbps per wavelength channel.

“Now we’re talking 100 Gbps upgrades. With the increased capacity, that’s like sending the contents of a hard disc drive from California to China in just one second. I find that amazing.”

Pioneers in undersea cable development

The original Bell System had a storied history in developing undersea cable. It’s a tradition we proudly continue today, with significant refinements.

The first transatlantic telephone cable was laid in the mid-50s, boasting all of 36 analog (voice) circuits. That meant only 36 conversations could take place at any one time. In 1988, the first fiber optic system allowed up to 38,000 simultaneously transmitted voice circuits on two fiber pairs.

Our pioneering innovation in network technology continued to change the dynamics of communication. Today, two hair-thin fiber optic strands can send more than 2.6 terabits of digital voice and data between the world’s continents over these deep-water highways.

In the early days, we owned our own ships. Today, we work with other U.S. and international providers (including our competitors). That way, we share costs and technology for the specially designed vendor ships and undersea cables.

It’s all managed out of our Global Network Field Operations group. We have an ownership stake in 80 of the undersea cable systems worldwide. It’s a network that stretches almost 437,000 miles, or 17.5 times around the Earth’s circumference.

“Our fiber and amplifier technology lets us cost-effectively upgrade our cable and keep our customers connected,” said Tom McInerney, who heads our undersea cable operations. “It costs hundreds of millions of dollars to lay a new undersea cable. We can upgrade system capacity by changing out the end-point electronics with that technology.”

To protect them from the enormous pressures of the ocean depths and to withstand handling, the cables are armored and have layers of steel and polyethylene. In shallow areas, the cable is double armored and sometimes buried. When it’s all packaged up, the cable is just over half an inch in diameter – about the size of a garden hose.

Here’s how it works:

  • Overseas calls or data travel to a switch on our domestic network and from there to one of our cable stations.

  • The call is routed to an undersea cable.

  • Repeaters located every 30-60 miles boost (amplify) the optical fiber signal toward its destination.

  • When necessary, branching units can split a cable to a different continent or landing point.

  • The signal emerges at a distant end cable station, and the reverse terrestrial process occurs until it’s delivered to the intended recipient – all in a matter of hundreds of  milliseconds.

Guam: Strategic transit station

Guam has long been a strategic island for the United States, first for the military. Now it’s a transit station for our undersea cables that connect the U.S. with Asia. Acquired by AT&T in 1963, the Tanguisson station remains a symbol of the Cold War. Its outside walls are 24 inches thick, designed to withstand a nuclear attack.

Today the building protects our circuits and cables from attacks by Mother Nature. And in the middle of the Pacific, Mother Nature can have quite a temper. Like other critical pieces of our network, our goal is to keep the cable landing station connected regardless of the weather.

Roland Mondia is a field operations technician who maintains the station’s electronics during good times and bad. When it’s bad, he doesn’t leave until it’s better.

“Probably my worst experience was working during Super Typhoon Pongsona in 2002,” he said. “In that kind of weather, you’re isolated from the rest of the island, because all roads are closed. Air Force weather instruments measured winds at 200 miles per hour – and then the weather instruments blew away.

“AT&T really stood out. While we lost commercial electricity, we stayed on generator power for 62 days. We were able to stay open to keep families and businesses in the Asia and Pacific area connected with the best possible communications. That was a real proud moment for me.”

When it doesn’t work

Close to shore, where the oceans are shallow, we use cable plows and remote vehicles to bury the cable in the ocean bed. Once the cable enters deeper water, it is typically laid on the ocean floor.

Every once in a while, a hungry or curious shark might nibble at a cable. But the biggest cause of undersea cable damage is man. Vessels drag nets and dredges over a cable, or drop an anchor that damages it. Natural events like undersea landslides and earthquakes also damage cable. These events are less frequent but can be more devastating.

Regardless of the depths, undersea cables are hauled to the surface to make repairs. Hooks on long ropes are used to cut and recover the cables from the seabed. In depths greater than 6,000 meters – just under 19,700 feet – it takes three to four hours just for the hook to reach the seabed from the surface. Typically, it takes twice as long to bring it back up to the repair ship. 

We set the standard

Even if a cable is damaged, there is redundancy built into our network so the communication path automatically reroutes until the repair is made.

“We have our cables mapped, so when a break happens in the middle of the ocean, we know where it is and what’s needed to make the repair,” Tom said. “We scramble special repair ships within 24 hours.

“They will pull up the cable, find the break, splice it back together and place it back on the ocean floor. During the repair process, the repair ship and cable station staff work 24 hours a day until our cable is back on line.”

In the end, it’s all about connectivity, and around the world, our standards and processes are considered the best.

“I’m really proud to be part of the AT&T team,” Roland said. “Our undersea cable operations provide improved communications around the world that help promote education, telemedicine and more. It’s really great to be part of that effort.”