When 7-year-old John Cioffi ran up to the Bell System pavilion at the 1964-1965 World’s Fair in New York City, he couldn’t wait to see the first telephone with video: the much-lauded Picturephone.

The boy had been disappointed that phone calls provided only audio. He gazed up at the Picturephone’s oval screen, with its grainy, black-and-white video images—the culmination of US $500 million in R&D by the telecommunications giant—and thought, Wow…that looks terrible!

“That memory always stayed in the back of my mind,” Cioffi says. “As I went through my schooling and career, it seemed that the technology should be able to get there, and I was always curious about how we could make it happen.”

Nearly three decades later, at age 35, Cioffi developed the technology that would ultimately make possible video calls and much more including high-speed Internet. In 1991 he built the first asymmetric digital subscriber line (DSL) modem, which quickly replaced most dial-up connections. DSL meant a user could download data-heavy images and videos while simultaneously browsing the Internet and talking on the telephone, all from a single phone line.

DSL works by separating digital voice and data signals, then converting them into analog signals that can be sent far more quickly and easily over wires—typically the copper lines already found in landline telephones. Cioffi is known as the “father of DSL” not only because of his creation of the first such modem but also his work to commercialize and popularize the technology.

For his DSL efforts, Cioffi received a U.S. National Medal of Technology and Innovation, one of 12 bestowed in October by President Biden during a White House ceremony. The medal, the nation’s highest award for technological achievement, recognizes U.S. innovators whose “vision, intellect, creativity, and determination have strengthened the country’s economy and improved the quality of life,” according to the White House.

“I was awestruck and never imagined that they’d select me for this one, as there are so many [people] I can think of who’d be more deserving,” says Cioffi, an IEEE Life Fellow. “I came to learn that several [of my] former students—Dr. Krista Jacobsen, Professor Katie Wilson, and Dr. Pete Chow—were the nominators.”

The technology led to high-speed Internet, with data capacities and transmission rates that were unimaginable with dial-up systems. What’s more, DSL relied on the copper wires that phone companies insisted to Cioffi were passé, thereby unlocking a future forever altered by connectivity.

Read full article, "How the Inventor of DSL Altered the Course of Connectivity Stanford professor John Cioffi’s tech led to high-speed Internet."