1. Radiowave Transmission :
The radio waves have frequency range from 3 KHz and 1 GHz. These waves are easy to generate and these can travel along long distances. These waves are omni directional in nature which means that they can travel in all the directions. They are widely used for the communication between both indoor and outdoor because they have the property that they can penetrate through the walls very easily. These waves are usually used for AM and FM radio, television, cellular phones and wireless LAN.
2. Microwave Transmission :
Microwaves are the electromagnetic waves which have frequency range between 1 GHz to 300 GHz. These can travel along long distances. These are unidirectional in nature which means that they can travel only in straight line. At very high frequency that cannot penetrate into walls. These waves are usually used for one to one communication between sender and receiver, cellular phones, satellite networks and wireless LAN.
3. Infrared Waves :
Infrared Waves are the electromagnetic waves which have frequency range between 300 GHz to 400 GHz. These cannot travel along long distances. These waves are used for short range communication and they also use line-of-sight of propagation. These waves cannot pass through solid objects like walls etc. These also not penetrate through walls. The most common application of the IR waves is remote controls that are used for TV, DVD players and stereo system.
Difference between Radio wave, Microwave and Infrared waves :
Sr. No. Basis Radiowave Microwave Infrared wave 1. Direction These are omni-directional in nature. These are unidirectional in nature. These are unidirectional in nature. 2. Penetration At low frequency, they can penetrate through solid objects and walls but high frequency they bounce off the obstacle. At low frequency, they can penetrate through solid objects and walls. at high frequency, they cannot penetrate. They cannot penetrate through any solid object and walls. 3. Frequency range Frequency range: 3 KHz to 1GHz. Frequency range: 1 GHz to 300 GHz. Frequency range: 300 GHz to 400 GHz. 4. Security These offers poor security. These offers medium security. These offers high security. 5. Attenuation Attenuation is high. Attenuation is variable. Attenuation is low. 6. Government Licence Some frequencies in the radiowaves require government license to use these. Some frequencies in the microwaves require government license to use these. There is no need of government license to use these waves. 7. Usage Cost Setup and usage Cost is moderate. Setup and usage Cost is high. Usage Cost is very less. 8. Communication These are used in long distance communication. These are used in long distance communication. These are not used in long distance communication.