SANDY — Jaydene Washburn's rambler-style home here, 20 minutes south of Salt Lake City, seems the epitome of suburban tranquillity.

The neatly cropped lawn is free of weeds. The skis and bicycles are hung tidily in the garage. In the house, the walls are adorned with family photographs and religious images.

But look up at Washburn's roof and you notice a sign of one of the first great business battles of the 21st century: an antenna that reaches four feet above the shingles. Her family recently paid $400 to a startup called Utah Broadband to install the antenna because she was tired of waiting for the industry's major competitors, the telephone and cable companies, to provide high-speed, or broadband, Internet access.

Washburn, who teachers fourth grade, said she wanted to make the switch because her old dial-up access was excruciatingly slow when she tried to gain access to educational Web sites, when her sons played online games or when her husband sold refurbished golf clubs on eBay.

Like the building of the railroads in the 19th century and the development of the highway system in the 20th century, the wiring of America represents huge opportunities for companies large and small. To the winners will go monthly access fees from tens of millions of households and businesses.

The competition in the Salt Lake area mirrors that in towns and cities from Portland, Ore., to Portland, Maine. It pits behemoth cable companies against telephone companies, and both against a growing number of small entrepreneurs who want to use wireless technology to bypass the telecommunications infrastructure. All of the contenders are struggling to reach people like Washburn, knowing that whoever arrives first has an advantage.

About 14 percent of American households have broadband, amounting to a third of those with Internet access. They pay $30 to $60 a month for the service. Growth prospects for the market are strong, according to Patrick Mahoney, an analyst at the Yankee Group, a technology market research firm. Revenue from high-speed Internet service is expected to increase to $20.8 billion in 2007 from $7.4 billion in 2002, he said.

Technology industry analysts say high-speed computer links are being adopted more quickly than virtually any technology in American history. Still, other countries are ahead. The United State ranks 10th in the world in terms of the percentage of inhabitants with high-speed access, known as broadband behind Canada, South Korea and Japan.