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Data communication and transmission speed, channel, method

, মে ২২, ২০২০ WAT
Last Updated 2021-03-25T05:32:16Z


Data Communication

Data communication is the process of transferring data from one place to another or from one computer to another computer or from one device to another.

There are 5 components of data communication, namely-

1. Source
2. Transmitter
3. Medium / Transmission System
4. Receiver
5. Destination

1. Source: Data Communication Source's job is to create data. Examples- computer, telephone etc.
2. Transmitter: The function of the transmitter is to transmit data from one source to another or from one computer to another computer or from one device to another through the transmission system and encode it in the data security provision. Example- A modem receives digital data as input from a computer and converts that digital data into an analogue signal to facilitate movement through the transmission system.
3. Medium / Transmission System: The medium through which data is transmitted. Example - wire or air.
4. Receiver: The customer's job is to receive the signal from the transmission system and present this signal in a way that the destination device can understand. The customer-friendly modem converts that analogue signal into digital data. Example- Modem.
5. Destination: Destination device receives original data from the receiver. Example- a computer.


Data Transmission Speed

The rate of transfer of data from one place to another or from one computer to another or from one device to another is called data transmission speed. This data transmission speed is often called bandwidth. Bandwidth is calculated in Bit per second (bps).

Data transmission speeds can be divided into three parts, viz.

  • Narrowband
  • Voice band
  • Broadband
Nero Band:
Narrow bands usually have speeds of 45 to 300 bps. This band is used for slow data transfer. Such bands are used in telegraphy. In the case of narrow bands, the transmission speed is lower due to higher cable usage. This band is used in telegraphy.

Voice Band:
The voice band usually has a speed of 9600 bps. It is more commonly used on the telephone. However, this band is used for data transfer from a computer to a printer in computer data communication. This band is used in telephone lines.

BroadBand:
Broadband is a high-speed data space band with speeds of up to 1 megabit per second (Mbps). This band is commonly used in data transfer in co-acrylic cables and optical fibres. Moreover, this band is used in satellite or microwave communication.


Data transmission channel (Data Transmission Channel)

The connection between both transmitter proofs and remote receiver proofs required for data exchange. This connection is commonly called a channel. The following are some of the types of channels -

  • A) cable
  • B) Ordinary Telephone Line
  • C)  Radio Wave
  • D) Microwave
  • E) Geo-satellite system
  • F) Infrared etc.
Cable
Cables are usually used to move relatively small amounts of data over short distances. However, advanced types of cables are used for high-speed data communication on a large scale.
There are different types of cables-

  • Coaxial cable
  • Twisted Pair Cable
  • Fibre optic cable  (Fiber Optical Cable)
(Coaxial cable)
Such wires are made of two conductive and non-conductive materials. They contain non-conductive material in the middle to keep the inner conductor separate from the outer conductor. The outer conductor is again covered with a plastic jacket. The inner conductor is kept straight and the outer conductor is twisted from all sides.

Twisted Pair Cable:
Twisted pair cables are made by twisting two non-conductive wires together. An insulating material is used between the two to keep the twisted wires apart. Data cannot be transmitted over a distance of more than 100 meters using such cables as the transmission loss is very high in such cables.

Fibre Optic Cable:
The cable through which the light signal can be transmitted is called fibre optical cable. Through this cable, it is possible to send light signals far away in the form of full reflection. Made with very fine glass particles, the fibre optical cable is almost as thick as two human hairs. Inside the high-quality rubber coating, the optical fibre is made of glass coating. The cable has the advantage of bending the inner glass coating lightly so that it does not break easily. Information is rapidly exchanged through the hollow part of the glass.
This cable has a special type of device for transmitting electrical signals to light signals. There is another type of device that converts light signals into electrical signals.
Features-

  • Information can be exchanged at high speed. Usually 18,000 miles / second.
  • Small in size and extremely low in weight.
  • Free from electromagnetic effects.
  • Energy dissipation is low.
  • Transmission loss is extremely low.
General Telephone Line
Both data and voice can be communicated through telephone lines. This type of communication is widely used in almost all countries of the world. The speed of sending a digital signal to the telephone is usually from 1200 bits to 5600 bits per second.

Radio wave
Radio waves can be easily made, can be carried far and wide, and radio waves can penetrate many things in buildings, so the use of radio waves is widely used in communication. In this system, the speed of sending the signal is 24 kilobits.

Microwave & Ground Satellite System  (MicroWave)
Artificial satellite systems can transmit one type of electromagnetic wave from one computer to another with the vibration of about one gigabyte or more per second. This type of wave is called a microwave. Using this connection, data, words, pictures, etc. can be transferred from one computer to another in different countries of the world.

Inaphraredah (Infrared)
Infrared is a type of electromagnetic wave, the frequency range of which can be up to terahertz. In this technology, the work of transmitting the signal is done through the LED. The photodiode at the receiving end acts as the signal receiver.


Data Transmission Method (Data Transmission method)

The data transmission method can be divided into three parts. E.g. -

  • Asynchronous transmission
  • Synchronous transmission
  • Isochronous transmission
(Asynchronous transmission)
A data transmission system is a character-by-character transmission from the sender to the data receiver is called asynchronous transmission. The main features of this data transmission are-

  • The sender will be able to send data at any time and the customer will also be able to receive it.
  • The interval between transmitting a character and transmitting another character may not always be the same but may be different.
  • A start bit is transmitted at the beginning of each character and a stop bit at the end.
  • Start bit 8-bit character stop of bit asynchronous transmission.
 Advantages:

  • The sender can transfer the data at any time and the customer can receive it.
  • The sender does not need a primary storage device for data transmission.
  • This method is quite useful when a small amount of data needs to be transferred.
  • This method is simple and low cost.
Use of Asynchronous transmission:

  • From any computer to a printer.
  • From computer to punchcard reader or from punchcard reader to the computer.
  • This method is used to transfer data from the keyboard to the computer.

(Synchronous transmission)  The synchronous transmission system, the transmitter station and the data stored on the device is a primary s. The data characters are then divided into packets and transmitted one at a time.
The main features of this data transmission are-

  • The data is transmitted in the form of baskets or packets.
  • The time between two consecutive is always equal.
  • A piece of header information is to be sent at the beginning of each data and Taylor information at the end.
Advantages of synchronous transmission:

  • The efficiency of the synchronous transmission system is higher than that of the acycranus.
  • This method speeds up data transmission.
  • There is no need to transmit a start bit at the beginning of each character and a stop bit at the end
  • Data transmission takes relatively less time.
Use of synchronous transmission:

  • In the case of data transmission from one computer to another.
  • In the case of remote data exchange.
  • In the case of a lot of data space at once.

Aisokronasa transamisanah  (Isosynchronous transmission)
Isochronous transmission can be called an improved version of synchronous transmission. This keeps the data transmission delay between the recipient and the sender station to a minimum. That is, an attempt is made to do about 0 (zero) single time during the data transfer of two consecutive. This method is commonly used in real-time application data transfer.


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