The cable guy is becoming sleeker and more sophisticated, just like the televisions and computers he installs.

Long depicted as slovenly cranks who dodged growling dogs and tracked mud on the living room carpet, cable guys (and gals) these days often have backgrounds in engineering and computer science. That kind of training is now required — along with a new dress code for some, calling for button-down dress shirts and slacks — as cable companies and their telephone rivals try to lure customers and increase revenue with a suite of products like cloud-based cable boxes and iPad apps that let subscribers set recording times remotely.

All that means added pressure for installers and new requirements for a job that traditionally appealed to high school graduates looking for reliable blue-collar work.

“Back in my day, you called the phone company, we hooked it up, gave you a phone book and left,” said Paul Holloway, an area manager based in Denton, Texas, and a 30-year employee of Verizon, which offers phone, Internet, television and home monitoring services through its FiOS fiber optic network. “These days people are connecting iPhones, Xboxes and 17 other devices in the home.”

Robert Kolb, a 33-year-old installation and service supervisor for Comcast’s Xfinity television, phone and Internet service, has a one-year certification in network engineering. He wore pressed slacks and a sporty fleece jacket on an Internet upgrade job in a Philadelphia suburb recently.

He was checking the family’s existing Internet service, which had been spotty, strained by the home’s six computers and multiple iPhones.

The surge in high-tech offerings comes at a critical time for cable companies competing in an increasingly Internet-based marketplace. Today, more than 90 percent of the 115.9 million U.S. homes with televisions subscribe to basic cable, either from a cable operator or a satellite or phone company, according to Nielsen.

The nearly saturated marketplace means growth for cable companies must come from all the extras like high-speed Internet service, home security, digital recording devices and other high-tech upgrades. In 2011 Comcast introduced 16 products, more than the previous two years combined.

“We think the consumer wants a state-of-the-art experience,” Brian Roberts, Comcast’s chairman and chief executive, said as he showed off the company’s forthcoming partly cloud-based cable box. Remote control in hand, he added: “We have to factor in Androids, iPhones, tablets and any other device in your life.”

But despite their enhanced stature and additional responsibilities, technicians haven’t benefited much financially. The median hourly income in 2010 for telecommunications equipment installers and repairers was $26.30, or about $52,850 annually. That was up only 0.4 percent from 2008, according to the Bureau of Labor Statistics.