How is Cable TV Transmitted?

Cable television is a common amenity in most people's homes. There are hundreds of available television channels, each one loaded with valuable or entertaining programming, and watching TV is one of the most common pastimes of families across the country. More than that, cable companies also offer Internet and phone service, making cable companies essential providers of household utilities.

Although cable plays an important part in the lives of many people, most cable subscribers don't spend much time thinking about how and why the technology works. Understanding the history and current technology of cable can help foster a greater appreciation for television service, however, and it can also help explain why cable television costs what it does and has the benefits and limitations that it does.

A Brief History of Cable Television

Like radio, cable television is broadcast over radio waves. These waves are received by antennas, which transmit the signal into the television through a cable. From there, the television transforms the radio waves into sound and picture. Originally, only people whose homes were in direct line of sight from the broadcasting station could receive television signal. This meant that viewers in the 1950s were severely limited by location. People living in rural areas or in mountains were unable to get television signal to their homes.

In order to combat this problem, individuals in rural areas began placing television antennas outside in high places, like rooftops or even mountain slopes. From here, the receiver could pick up signals broadcast from the cities as the line of sight between the transmitter and receiver was uninhibited. A long cable would be run from the receiver to the television to enable the viewer to watch television.

Today's cable television is quite similar to this homemade solution, but the technology is somewhat more sophisticated.

Cable Television Today

Cable networks broadcast out of many cities across the country, and the same networks are available to subscribers nationwide. In order to make cable television accessible to viewers all over the country, cable companies must boost their transmission signals. This requires the use of strategically placed signal amplifiers. These amplifiers capture, strengthen and re-broadcast television signals to make them easier for viewers to receive at home.

Individuals can still use a television antenna to pick up some TV stations. The higher and larger the antenna is, the better its chances of picking up faint signals. However, not every cable network will be available to people searching for television in this way. People looking to receive a full range of cable channels will need to get a cable box from the local cable company.

The purpose of this box is to decode transmissions broadcast by cable companies. Before broadcasting, cable companies scramble their signals to prevent people from accessing them for free. In order to receive the decoded transmissions, viewers must pay for a cable subscription. The level of cable purchased determines which networks will be decoded.

Newest Technology in Cable Transmission

The cable used to connect a receiver to the television is usually a coaxial cable, which is made up of numerous fine wire filaments. These filaments, which are usually made of copper, are highly conductive. Faster cable television is available, however, through the use of fiber optics. Fiber optic cable is smaller and lighter than copper, and it provides less friction. This allows it to transmit electrical impulses and radio signals at a high speed, and it's responsible for the fastest high-speed Internet available through cable.