Wireless Local Area Network uses two basic transmission technologies for its setup. They are infrared transmission and radio transmission technologies.
Infrared Transmission Technology
Infrared light uses non visible light of the electromagnetic spectrum. The spectrum is defined as the band of frequencies assigned for various types of transmission. Infrared light
is produced by the LED at the transmitter end and is received by the photodiode detector at the destination. Detector is used to convert the light into electrical signals for further processing. LED works on the principle of electroluminance which produces light due to the effect of electric field. LED produces light due to recombination of holes and electrons which produces energy in the form of light. The type of energy produced depends on the substrate used for fabrication.
The advantages of infrared transmission are:
- 1. Low cost.
- 2. Transmission is secure.
- 3. Not affected by weather conditions like rain, thunder etc.
The disadvantages of infrared are:
- 1. The transmission requires line of light for propagation.
- 2. The infrared transmission is blocked by the objects like buildings, trees, walls etc.
- 3. Not reliable type of communication.
- 4. Not suited for large coverage area.
Radio Transmission Technology
Radio transmission is used in today’s scenario. To overcome the disadvantages of infrared transmission, radio technology was produced.
The advantages of radio transmission technology are:
- 1. This transmission do not require line of sight for propagation.
- 2. The rays are also not blocked by the objects like buildings, trees etc coming in its way.
- 3. It is a reliable form of communication.
- 4. Radio transmission covers more area than infrared transmission technology.
- 5. Provides high data rate. Data rate is defined as the bits per second. Bit is the smallest unit of data.
- GATE Syllabus for Electronics and Communication Engineering
The disadvantages of radio transmission technology are:
- 1. Quite costly for a coverage area of few meters.
- 2. This transmission is disturbed by the weather conditions.
- 3. This transmission is not secure as compared to infrared technology.
- 4. Licence is required for some products.