Wireless media: Wireless communication is a type of communication system that does not require any type of cable. In wireless communication, the sending device connects one computer to another computer or one device to another device through the radio web.
Characteristics of Wireless Media: Wireless media do not use electrical or optical conductors or wires. In most cases, the Earth's atmosphere acts as the physical path for data transmission. Wireless systems are used when there are obstacles in the way of data transmission and installation of wired media is problematic.
The three types of wireless media are --
(i) Radio Wave
(ii) Microwave
(ii) Infrared
Radio wave: Network data is transmitted through radio transmission in the same way that signals are transmitted in radio. In this case every computer in the network can receive the signal sent by it. Radio wave frequencies are limited to 10 kHz to 1 GHz. The limited electromagnetic spectrum between 10 kilohertz and 1 gigahertz is called radio frequency (Radio Frequency-RF). Radio waves are divided into three categories. These are --
Low power single frequency: This type of radio wave works only in one frequency. It is also known as narrowband. The cost of this transmission system is relatively low. Installing transmission equipment is quite simple. Transmission speed is 1 to 10 Mbps.
High power single frequency: This type of radio wave can travel a greater distance than the low power single frequency class radio wave and is able to penetrate if there is an obstacle on the way. Due to its high power, signal quality does not degrade much over distance. By using repeaters, the range of the signal can be extended. Its installation is complicated. Transmission speed is 1 to 10 Mbps.
Broad spectrum: In this system, instead of a single frequency, data signals are sent through a specific range of frequencies. The system in which the signal is coded is called chips. The security of the signal can be ensured through this coding technology. The frequency range available in radio waves is divided into several channels. During signal transmission the adult is tuned to a predetermined frequency. Then the adapter is tuned to a different frequency. Thus the data transmission takes place on the designated channel.
Microwave: Microwave system is a series of electromagnetic waves. The wavelength of the electromagnetic web is usually 1 mm to 1 m. Or between .3 GHz and 300 GHz. Currently, microwave is a very popular method for long-distance data transmission in different countries of the world. Data, images, sound can be transferred using microwave connection. Data is not transmitted if there is an obstacle between the sender and the receiver through microwaves.
Characteristics of microwaves:
(i) MicronWide system basically consists of two transceivers. One of these is used for transmitting signals and the other for receiving.
(ii) Microwave antennas are placed on tall buildings or towers so that the signal travels a long distance.
(iii), the antenna is mounted on a tall building or tower so that it is not obstructed by anything while crossing the bridge.
(iv) Microwaves cannot travel in curved paths.
Terrestrial microwave: In terrestrial microwave technology, the transmitter and receiver are placed on the surface. It uses frequencies below the MHz frequency range. The transmitter and receiver have line-of-sight communication and cannot cross any obstacles to signal movement (eg tall buildings) and do not cross any curves.
Satellite microwave: This technology requires the help of communication satellites. In this, a communication satellite placed 36000 km above the earth (geosynchronous) rotates at the same speed as the earth. The receiving antenna used on the ground for this satellite is parabolic. Satellite transmission is used where normal cable communication is not possible. Satellites are no substitute for networking, especially in countries that are located on oceans or large landmasses. Besides, it is possible to connect with many countries by using a single satellite.
Infrared: Infrared system is a type of electromagnetic web with a frequency range of terahertz. This technology uses infrared quality light to signal. The task of transmitting the signal is done through LEDs or ILDs. The photodiode at the receiving end receives the signal. The characteristic of the infrared signal is that it cannot pass through walls or other energy sources. In addition, infrared signals disappear when exposed to strong light sources.
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