Cable TV is an analog of the television broadcasting model, where the TV signal is distributed through a cable that goes to the consumer and also transmits sound. This method began to spread actively in the 1980s in Europe and America. This method of broadcasting allows the consumer to watch more than sixty channels in high quality and not be afraid of interference.

What is digital television?

Digital television is a broadcasting method in which a television signal containing image and sound is encoded using digital channels. Currently, the most popular data encoding method is MPEG. This method has a number of advantages: stability, reduced transmitter power, a much larger number of programs in one frequency band, excellent sound and image quality, many useful functions, and the ability to select a language. If you decide to connect digital TV, you only need to buy a small set-top box, but even that is not necessary, as many modern TVs have long supported the DVB-T2 standard.

It is important to understand that comparing digital and cable TV is pointless and makes no sense. Cable television is essentially one of the ways to deliver information to subscribers, while digital television is a type of video and audio signal transmission. Satellite or terrestrial television is put on a par with cable television, while digital television is compared to analog.

What are the main pros and cons of cable TV?

Pros:

• Good sound and picture quality, which is far ahead of analog, although not as good as digital.
• Resistance to interference, this parameter is approximately at the same level as that of digital.
• A large number of channels, but this is also inferior to digital.

Cons:

• Strongly depends on the operator.
• It’s impossible to get it in a village or town. Even in some cities, in remote areas, it will be problematic to lay a cable for a subscriber, which is undoubtedly a disadvantage.
• Installation prices for each operator are different and can range from inexpensive to exorbitant.

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Cable TV networks began to actively develop in Europe and the United States in the 1980s. For a long time, coaxial cable has been the basis of cable TV networks. The successful development of optical transmission technologies led to the introduction of fiber optics in cable TV networks in the form of so-called hybrid fiber-coaxial networks, which combine coaxial and fiber-optic cables.

A modern cable TV network includes a headend, trunk channels, sub-trunk lines and home distribution networks.

Advantages of cable television over terrestrial television:

• higher signal quality;
• high interference immunity;
• No problems with signal transmission in cities with dense high-rise buildings;
• The possibility of expanding the services provided to the subscriber and the number of channels.
• A large number of TV channels (often at least 60).

Traditionally, analog cable TV technology is successfully mastering the digital transmission methods, both direct to the customer (DVB-C) and two-way interactive (DVB+IP, DOCSIS).

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signal sources
headend station
switching and distribution network.

Cable television scheme

The design of cable television is formed depending on the location of the headend and antennas relative to each other and other components. The combination of devices guarantees a clear signal. The basic element in the scheme is the main amplifying station. It contains the main equipment for processing data from various sources.

Amplifiers, decoders and modulators are mounted on a rack-mounted chassis, individual for each TV channel, and make it possible to correct signals before combining them into a package for transmission to the consumer. Such devices make it possible to improve a bad signal. All principles of operation and network organization are based on this cable broadcasting scheme.

Switching and distribution network

In cable television, the broadcast signal is distributed via coaxial cable using splitters and couplers.

Splitters divide the signal equally;
Couplers – distribute more power to longer cable sections and less to shorter ones.

The desire of cable operators to increase capacity and transmit the Internet along with the TV signal, creating double tariffs, led to the replacement of coaxial cable with fiber optic cable. It is less demanding on the environment, resistant to interference, has a perfect amplitude-frequency response and a long service life. The pulse from the headend is compressed into an optical signal and transmitted over the fiber optic network.

Optical modulator

An optical demodulator is installed and maintained by the operator at each entrance, which converts the signal into TV.

Do I need a digital set-top box for cable TV?
The types of cable TV are the same as terrestrial TV. It is easy to determine whether you have digital or analog cable TV by the presence of additional equipment that was needed to connect the TV. Broadcasting an analog signal does not require any special auxiliary devices. Only a coaxial cable will be brought into your apartment and plugged into the TV.

When it comes to connecting digital cable TV, you will be offered to buy or rent a receiver. Do not confuse it with a digital set-top box for terrestrial broadcasting. The principle of their operation is similar, but the digital cable TV standard is called DVB-C, and each operator has a different encoding. Therefore, the device must be purchased specifically from this operator.

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