Data Communication

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What are data communication and communication media? Explain communication media with examples in detail.

Data communication
Data communication is a process of transferring data electronically from one place to another. Data can be transferred by using different transmission media and communication devices such as transmitter and receiver.

Basic Elements of Data Communication
The following components are required for successful communication to take place:

  1. Sending Device
  2. Receiving Device
  3. Communication Device
  4. Transmission Medium

Communication Media
A path through which data is transmitted from one place to another is known as communication media. It is also known as communication channel. The standard telephone line, twisted pair wire, coaxial cable, fiber optic cable, microwave, satellite etc are examples of communication channels.

Types of Communication Media

  1. Physical Transmission Media, and
  2. Wireless Transmission Media

Physical Transmission Media
In bounded media, communication devices are directly connected with each other by using some physical media like wires. Some examples of bounded or physical media are twisted pair wire, coaxial cable, and fiber optics.

1. Twisted Pair Wire
Twisted Pair consists of a pair of copper wires. The pair of wires is covered by a plastic insulation and it is twisted together. Twisting of wires protects them from interference by external electromagnetic waves. It is used in LAN to connect computers and other devices.

2. Coaxial Cable
Coaxial cable consists of copper wire covered by an insulating material. The insulated copper wire is covered by copper mesh. The mesh protects the data signals from interference by external electromagnetic waves. Coaxial cables are used by the cable TV network and telephone companies.

3. Fiber Optics
Fiber optics consists of thin strands of glass or plastic called core. The strands are thin like human hair. The core is the center of the fiber optic cable that uses light to transmit data. Each strand is surrounded by a layer of glass inside the fiber optic cable called cladding. The cladding is further protected by a plastic coating called jacket. Most telephone companies, ISPs and cable TV operators are using fiber optics in their networks.

Wireless Transmission Media
In unbounded media, communication devices communicate with each other through air or space using broadcast radio signals, microwave signals and infrared signals. Unbounded media are used where it is impossible to install cables. For example microwave transmission, communication satellite, and mobile communication.

1. Microwave Transmission
In microwave transmission, data is transmitted through air or space, instead of cables or wires. Microwaves are high frequency radio waves. Microwave uses line-of-sight transmission through space.

2. Communication Satellite
Satellite communication system consists of a satellite and several earth stations. The communication satellite is a space station. It is approximately 22,300 miles above the earth. Each earth station consists of large dish antenna. It can send and receive data signals.

3. Mobile Communication
Mobile communication is a radio based network. It sends and receive data to and from the mobile computers. The data is communicated through radio signals from one location to another.