Computer Knowledge: About Wireless Technology in Data Communication for IBPS, SBI and Other Competitive Exams

Unguided Media ( Wireless Technology)

It is the transfer of information over a distance without the use of enhanced electrical conductors or wires. When the computers in a network are interconnected and data is transmitted through waves, then they are said to be connected through unguided media. Some commonly used unguided media of transmission are;

1) Radiowave Transmission:
When two terminals communicate by using radio frequencies then such type of communication is known as radio-wave transmission. This transmission is also known as Radio Frequency (RF) transmission. These are omnidirectional. Radiowaves are propagate in the sky mode, can travel long distances. Each computer attaches to an antenna that can both send and receive radio transmission.

Radiowave transmission setup has two parts:

• Transmitter: The devices which transmit signals, are termed as transmitter.
• Receiver: The devices which received signals, are termed as receiver.

Advantages and Disadvantages of Radiowaves
Advantages		Disadvantages
1	Cheaper than wired network	Insecure communication can be easily taped.
2	Provides Mobility	It is affected by the weather conditions such as rain, storms, thunder, etc.
3	Easy to use over difficult terrain.

2) Microwave Transmission:

Microwaves are electromagnetic waves having frequencies range from 0.3 to 300 GHz. Microwaves are unidirectional. Microwaves have a higher frequency than that of radiowaves. Microwaves is one of the fastest media for data transmission over communication channel. They can be aimed at a single direction instead of broadcasting in all direction. Microwaves antenna placed on the top of buildings. It consists series of stations approx 30 miles apart. It is used in cellular network and television broadcasting.

Advantages and Disadvantages of Microwaves
Advantages		Disadvantages
1	Cheaper than digging trenches for laying cables and using repeaters.	Insecure communication, as the taping of microwaves is easy.
2	Using microwaves, communication is possible even in difficult terrains.	It is affected by the weather conditions such as rain, thunder, storm etc.,
3		Cost of maintenance, implementation and design is high.

3) Satellite Communication:

The communication across longer distances can be provided by combining radio frequency transmission with satellites. It works over a long distance and fast communication. Satellite communication amplifies signal received from one Earth station, which can be located many thousand of miles away. It is used for communications to ships, vehicles, planes and handheld terminals.

Advantages and Disadvantages of Satellite   Communication
Advantages		Disadvantages
1	It covers a vast range of area.	It is very costly. So, it is preferred to use personal or low budget communication.
2	The wired communication is almost impossible and too costly to use across the continents where the satellite communication proves to be the best alternative.	There is atmospheric loss of transmitted signals.
3	It is very useful in television transmission.

4) Infrared Wave Transmission:

Infra red waves are the high frequency waves used for short-range communication. These waves do not pass through the solid-objects. They are mainly used in TV remote, wireless speakers.

5) Bluetooth

It is a wireless technology used for exchanging data over short distance to create a Personal Area Network (PAN) or piconet invented by Erreiscon in 1994.