The fortunes of the cable TV industry have changed radically over the years. Back in the nineteen seventies and eighties it was a great new way to get TV programming. It provided more channels than over the air TV broadcasts did and it didn't have the susceptibility to interference from weather disturbances that over the air TV broadcasts did. It also provided access to content that simply wasn't allowed to be aired over the airwaves because of FCC regulations. At this time, cable TV seemed like the ideal TV delivery technology and was something to aspire to.

Then, in the early nineteen nineties, satellite TV became a viable technology for a lot of people. The price of service had come down to the point where it was competitive with cable, it offered more channels, and the picture was better than cable. The cable TV industry took a big hit in subscribers, but it didn't take long to claw its way back up.

The first thing that the cable TV industry did in reaction to the incursion of satellite TV on its market share was convert over to digital transmission. Digital TV has a number of superior benefits to it when compared to the older analog TV transmission format. It offers a clearer picture, the ease of an interactive on screen program guide, and a digitally transmitted channel doesn't take up as much bandwidth as one transmitted in analog format. All of these were essential to gaining back the market share that the cable TV industry had lost to satellite TV. The clear picture of digital TV transmitted over a cable is the equal of a satellite TV transmission and much less subject to interference. The ability to conserve bandwidth was essential to being able to provide more channels, and an interactive on screen program guide makes sorting through all of the available programming options much easier.

One technological advancement that's been extremely useful for the cable TV industry is video compression. Just like any other kind of data that's transmitted digitally, video in the form of the TV channels can be compressed so that it takes up less bandwidth. For example, the MPEG-2 compression format takes up much less space than uncompressed video and the MPEG-4 format takes up roughly a quarter of the bandwidth of MPEG-2 video. That can make a big difference in the number of channels that can be supplied over a cable!

The technology that has cable TV poised to conquer satellite TV once and for all is Switched Digital Video, or SDV. SDV takes advantage of the fact that information can be transmitted in both directions over a cable. This allows a viewer to request a specific channel and the cable TV provider to just transmit that channel over the cable. Since only one channel is being transmitted over a cable at one time, this technology removes any practical limit on the number of channels that are available. That, combined with cable's superior ability to provide Internet service and video on demand, puts the cable TV industry in a great position to conquer satellite TV.