In the late 1980s, Joseph W. Lechleider came up with a clever solution to a puzzling technical problem, making it possible to bring high-speed Internet service to millions of households. His idea earned him a place in the National Inventors Hall of Fame as one of the fathers of the Internet service known as DSL.

Mr. Lechleider, who died on April 18 at his home in Philadelphia at 82, was an electrical engineer at the Bell telephone companies’ research laboratory, Bellcore. At the time, the phone companies wanted to figure out a way to send signals at high speed across ordinary copper wire into homes, mainly to compete with cable television companies and offer interactive video services.

Applying digital technology was the best route to sidestep the limitations of copper wire, but there was still a barrier. When the data speeds in both directions — downloading and uploading — were the same, there was a lot of electrical interference that slowed data traffic to a crawl.

Mr. Lechleider figured out that such meddlesome interference — known as electrical crosstalk — could be substantially reduced if the download speeds were far faster than the upload speeds. This approach became known as the asymmetric digital subscriber line. And these digital subscriber lines, or DSL, were how big phone companies like AT&T and Verizon brought fast broadband Internet into homes.