LED(Light Emitting Diode) Visible Light Communication(VLC) systems are recognized as creating a possible valuable addition to future generation of technology, which have the potential to utilize light for the purpose of advanced technological communication at ultra-high speeds surpassing that of current wireless systems. There exists a possibility that many of the problems associated with present day infrared, radio wave and microwave communication systems could be least partially resolved, and a more biologically friendly system made available to industries and the general public. Further advantage is that VLC system can transmit data more securely over short distances than radio frequency/micro wave communication devices whose signals can be easily detected outside the rooms and building they originate in.The advent of high-intensity, solid state LED are the foundation of this technology, and they allow us to provide wireless communication solutions with virtually unlimited bandwidth within the visual light spectrum.LEDs are extremely energy efficient and contain no hazardous materials as fluorescent lamps do. There by providing communications with virtually no cost as they are already being used for illuminating purposes.
Advantages of VLC
AUTOMATED TOLLBOOTH USING VLC
As frequent commuters on the Bangalore – Pune highway (NH-4), we have observed that the congestion near tollbooths at peak hours and weekends is so high
that it takes at least half an hour to clear them. On further enquiry we learnt that people are facing the same problem on most of the tolled roads. Hence sprang the
idea of automating tollbooths by using Visible Light from the headlamps of vehicles.
By integrating an optical receiver and a modulator to the headlamps of vehicles and to an array of reflectors which are already available near tollbooths for each
lane, we can make the transmitter on the vehicle to identify itself by giving its details like registration number, name of the owner, his/her primary and secondary
bank account numbers, and other details as stored on the RC book. As the vehicle nears the reflector, the receiver embedded into the reflector receives this data and
hence deducts the toll amount automatically from the account numbers specified. The vehicles need to pass over the array with a nominal speed rather than coming
to a dead halt as is the current situation. During daytime, a high power modulated LED beam near the reflector array signals the car’s receiver to switch on its
headlamps and transmit its data. The following are the major advantages in implementing the system.
Instead of hoardings, advertisements about hotels and resorts nearby can be transmitted to the driver thereby generating extra revenue for the government.
Limitations