In modern world we use many communication techniques. Of these one of the most important one is the visible light communication. The visible light Communications Consortium (VLCC) that is principally comprised of Japanese technology corporations was founded in November 2003. It promotes usage of visible radiation for information transmission through public relations and tries to determine consistent standards.
In visible light Communication project, the characteristic was further investigated for short transient time in turning the light on/off processes. A high-speed wireless communication system that is embedded in our LED lighting system was built. Also the duplex communication system consists of both downlink and uplink media through different frequencies of lights.
In this communication system, off-the-self elements were taken part in building the driving circuit and therefore the performance of the system was evaluated, such as, data transmission distance, data transmission rate and also the field of view of the transmitter.
Light Emitting Diodes
Light Emitting Diodes (LEDs) are utilized in consumer physical science, light bulbs, toys, cars, and monitors. With LEDs, it’s able to regulate light brightness at a frequency much more than typical light bulbs: LEDs will be switched on and off at very high rates. As result, LED-based lighting will be used for wireless communication services by modulating the intensity of the emitted light. Further, LEDs can even be used as receivers just like photodiodes. We call this idea visible light Communication (VLC) with LED-to-LED networking.
In literal terms any type of data that may be sent using a light signal that’s visible to humans could be considered to be VLC, but by the definition we should be able to see the light, but cannot “see” the data. Thus although there seems to be no universally agreed definition of VLC is, we will at least agree what we mean by VLC.
For Visible Light Communication we use LED as it is a modern technology for ubiquitous communication system. There are certain advantages for LED in VLC. They are:
- Long life expectancy
- Fast switching
- Less expensive
- Safe for human body
The VLC system is expected to undergo fast progress, inspiring various indoor and outdoor applications; but, several technical problems need to be addressed, particularly in outdoor surroundings.
Visible light communication has properties that are advantageous and disadvantageous compared to radio-wave wireless communication. The disadvantages are usually communication distance and data rate. In visible light communication the communication distance using is often between 1 to 100 meters. This distance is brief compared to radio-wave communication, because of the fact that visible light communication is essentially line-of sight communication, which implies that communication is interrupted when there\’s an object between a transmitter and a receiver.
There is another disadvantage of visible light communication that is data rate. Its data rate is usually between kilobits per second to 10 megabits per second, though there are active researches happening to achieve the speed of hundreds of megabits per second.0