Stewart Schley, DST Correspondent

When the first cable TV companies set up shop in the late 1940s to help people in isolated towns improve their TV reception, the prevailing approach was to provide signals over the same frequencies over-the-air stations used. As a result, once a coaxial cable was attached to a TV set, users could tune to their local stations using the tuning dial that was built into the set.

But once cable companies began to deliver extra channels like HBO and CNN in the 1970s, that approach changed. Customers required a new sort of TV tuner that would pick up signals outside of the normal broadcast TV frequency band. Thus was born the cable TV “converter,” a rectangular box that sat atop the TV set to perform its essential function: It converted higher-frequency signals that flowed over the cable to frequencies TV sets could accommodate. Ever since, a never-ending cycle of product improvements has been in motion, and hundreds of millions of cable “set-top” receivers have been installed in households across the U.S. If you’re like most U.S. residents, you have several set-tops in your home today. Today’s most sophisticated cable set-tops do much more than simply convert TV signals. Many include embedded computers that process digital TV signals, record television programs on computer-like storage disks, manage high-definition TV signals and allow customers to order movies and TV shows on demand, all with a few clicks of the remote.

But even as cable set-tops become more capable and sophisticated than ever, there’s an important change in the works. At the recent Consumer Electronics Show in Las Vegas, the top executives from several U.S. cable companies – including Cox Communications – announced a sort of back-to-the-future migration. After nearly a decade of development and complicated negotiations with consumer electronics companies, the cable companies unveiled a new way of distributing and controlling signals that could do to the set-top box what local Las Vegas showmen Penn and Teller routinely do on stage to an unwitting rabbit: make it disappear.

The idea behind the new technology is to make it possible for cable customers to enjoy the full range of cable services, including premium channels like HBO and popular interactive features like on-demand television, without the need for an independent set-top box. Instead, the various controls and authorization schemes needed to make these services available would be planted inside TV sets themselves, using an inventive software application devised by the cable industry.

The lubricant that makes this possible goes by the name of OpenCable Application Platform, or OCAP [click here for an OCAP primer]. It’s a technical specification that has two main purposes:

First, it will create a broad technology canvas that’s available for use by anybody who develops interesting interactive TV services. Like the Internet, OCAP uses open, published specifications to invite a wide range of developers to create new things to do over television. For example, Cox plans to use OCAP as a foundation for new interactive services like television e-mail, bill-payment options, caller ID over the TV screen, and single- and multiplayer video games, said president Pat Esser.

Second, OCAP will give TV set makers a chance to produce TV sets that do away with the need for a set-top receiver. Already, the electronics companies LG Electronics, Panasonic and Samsung have signed up to make equipment that uses OCAP. They believe a future selling point for new TV sets will be their ability to accommodate advanced cable services, like high-definition TV and on-demand television, without the need for a box.

The conversion won’t happen overnight. At the CES, several cable companies including Cox said they’ll start to introduce OCAP technology in selected markets beginning this year, with an aim toward ultimately using the technology nearly everywhere. Of course, cable companies will continue to supply set-top receivers of all types to their customers for a long time. But for the first time, there’s an agreed-upon way for cable and consumer electronics companies to collaborate on technology that will make new TV sets truly “cable-ready.” It’s a development the very first pioneers of cable television – in the era before set-top boxes – would be proud to see.

Stewart Schley is a freelance journalist who writes about media and technology from Englewood, Colorado.