LiFi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission.
LiFi is designed to use LED light bulbs similar to those currently in use in many energy-conscious homes and offices. However, LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. LiFi data is transmitted by the LED bulbs and received by photoreceptors.
LiFi's early developmental models were capable of 150 megabits-per-second (Mbps). Some commercial kits enabling that speed have been released. In the lab, with stronger LEDs and different technology, researchers have enabled 10 gigabits-per-second (Gbps), which is faster than 802.11ad.
Benefits of LiFi:
- Higher speeds than Wi-Fi.
- 10000 times the frequency spectrum of radio.
- More secure because data cannot be intercepted without a clear line of sight.
- Prevents piggybacking.
- Eliminates neighboring network interference.
- Unimpeded by radio interference.
- Does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft.
By using LiFi in all the lights in and around a building, the technology could enable greater area of coverage than a single WiFi router. Drawbacks to the technology include the need for a clear line of sight, difficulties with mobility and the requirement that lights stay on for operation.
Light might be the preferred option for transmitting data over long distances via cables, but when it comes to short range wireless, radio waves rule in the form of Wi-Fi and Bluetooth. Now Mexican company Sisoft, working with researchers from the Autonomous Technological Institute of Mexico (ITAM), has developed a wireless technology that transmits data in visible light emitted from LED lamps, while lighting the room at the same time.
Called Li-Fi, which is short for light fidelity, the technology is what is known as Visible Light Communication (VLC). Unlike infrared-based systems, VLC involves transmitting data using light visible to the human eye. In this case it is transmitted as intermittent, imperceptible flickers of light emitted by LEDs.
The team started out with audio, cabling up a protoboard table to a smartphone via its 3.5 mm audio jack. The protoboard table converted the audio signal into an optical signal that is transmitted by a special emitter across the spectrum of light generated by an LED lamp. At the receiving end, a receptor located in a speaker captured the signal and converted it back into an audio signal that was played by the speaker.
For wireless internet transmission, the principle is the same but makes use of a receptor device designed to be placed above a router. The router incorporates an LED lamp to transmit data so anyone falling within the halo of light emitted by the LED will be in range. However, only those with a receptor/transmitter device will be able to send and receive the signal.
The Sisoft team says it has used the technology to transmit audio, video and internet at rates of up to 10 gigabits per second. This is an improvement over similar Li-Fi systems developed at Siemens and Pennsylvania State University that achieved transfer rates of 500 Mbps and 1.6 Gbps, respectively.
In addition to its impressive transfer rate, Sisoft also highlights other benefits of the technology. Since the data is transferred via light, there is no way to hack it, making it safer, (although no mention is made of how easy it would be to take a peek at the data someone else is receiving). Additionally, it could be used in areas such as hospitals where radiation equipment can block or disrupt wireless signals. And of course, it provides illumination at the same time.
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