Invisible guides. Studying communication channels

Modern means and channels of communication do not serve usonly as intermediaries for information transfer. They are able to provide and maintain mechanisms and devices, supervise the work of employees, and remotely manage complex equipment.

Much has been said about the types of communication.We only list them. So, you can use telegraph, telephone, radio, sound broadcasting systems, television, satellite or mobile communications, new formats (3G, 4G, etc.), computer wired and wireless networks for data transfer. Moreover, thanks to the development of technologies in the field of communications and switching, the quality and speed of transmission is constantly growing. Communication channels play a significant role in this. About them will be discussed.

Types and classification of communication channels

Before talking about species, it makes sensedesignate the essence of the concept of "communication channels". By this is meant a system consisting of the medium in which the signal propagates, as well as a complex of technical devices and tools that provide and maintain signal propagation of a certain frequency with a certain speed.

As for classification or typology, at present, communication channels can be divided as follows:

• According to the type of conductive medium (cable or radio frequency).
• Over the frequency range (high frequency, VHF, UHF, microwave range, millimeter range, infrared).
• By type of signal (analog or digital).

Many have probably heard expressions such as digital communication channels or optical communication channels. What are their distinguishing features or advantages?

Digital communication channels transmit information in the form of a binary code, which

consists of only 0 and 1.Thanks to this technology, it was possible to achieve minimal data loss or corruption, in contrast to the analog method. For example, when talking on the phone, it is often the analog signal that is used, the principle of which is to transmit continuous electrical oscillations. That is why analog information exchange systems are very susceptible to interference and can significantly distort information or lose data.

Оптические каналы связи отличаются от других by the material from which the cable is made. Optical fiber used in their production allows to ensure high bandwidth of the channel, minimal distortion or reduction of the signal even at considerable distances, immunity to interference. In addition, fiber is economical to manufacture, much smaller and lighter in size. According to some sources, the weight of ordinary cables can be 10 times the weight of an optical wire of the same size. Optical communication channels are digital at the same time, since they transmit information in this form.

Нельзя не сказать и о беспроводных каналах связи.We use some of them without even thinking about it. An example of this is the infrared (laser) communication channel. It is he who allows us to control a TV or other device using a remote control that delivers a directional beam of light. Wireless channels include:

• Infrared or laser.
• Microwave channels (used for satellite or long distance communication).
• Network of free radio frequencies (the ability to transmit a signal in several bands at once).