Smart devices are exponentially growing in numbers every year, and the requirement for ultra-fast data is also inevitable to support a huge number of devices and applications. Our existing wireless technologies using radio waves has many limitations due to frequency and bandwidth, and it is highly vulnerable to security. What is Li-Fi technology, what is the working principle, and what are the applications?
Light Fidelity is a high-speed data transmission technology first introduced by Professor Harald Haas in 2011 during a TED talk. Li-Fi uses visible light as a transmission medium for data communication between devices.
How does Li-Fi work?
In a digital transmission system, data will be converted into binary bits in the form of zeros and ones equivalent to ‘on’ and ‘off’ states. Visible light is an ultra-fast electromagnetic wave with unlimited bandwidth to utilize. Human eyes can’t detect high-speed switching of light, but highly sensitive photodiodes can efficiently detect the modulation of light interacting with the detectors.
Compared to radio waves in conventional wireless systems, visible light has a thousand times higher bandwidth. Unlimited bandwidth makes it one of the most efficient solutions for data-intensive applications. Li-Fi technology is fast, full duplex, and a bidirectional communication system capable of data rates up to 224 gigabits per second.
Components of Li-Fi system
Data Access Point
The data access point connects the Li-Fi-enabled data transmission system with the internet via a high-speed router and switch. Basically, it acts as a smart hub that establishes connectivity between Li-Fi-enabled devices and the Internet. Higher-level modulation schemes and encryption techniques are being used to ensure secure communication.
Li-Fi enabled Light Source
Since the light source used in Li-Fi technology – LED bulbs are semiconductors, the same light can be used for transmitting data with fast switching of LED light according to high-end modulation schemes. Sophisticated transceiver act as a light source (for visible light) and data transmission node capable of securely sending and receiving high-speed data.
Visible light is the medium for high-speed uplink and downlink transmission.
Li-Fi-enabled smart device (transceiver)
A Li-Fi-enabled smart device has a photodetector (works as a receiver) and light emitter (works as a transmitter) for uplink and downlink. Once the device moves from the vicinity of one light source to another light source, the system re-establishes the connectivity like the traditional cell concept.
Our smart devices are not equipped with light detection sensors and transmitters. With modern semiconductor technology, Li-Fi can be integrated into a chip and easily added into future smart devices. PureLiFi and Philips are notable names in research on Li-Fi technology.
Smart dongles with Li-Fi technology are available for personal computers and other accessories like printers.
Advantages of Li-Fi
- Ultra-fast data communication – no limit to the data rate
- No interference like traditional radio waves
- Cost-effective solutions – much cheaper than other wireless technologies
- High-security data transmission – light can’t penetrate through walls, wooden doors, and metallic blocks
- Multiple device support – many devices without any limit and no network overloading
- Highly energy efficient solutions – energy spending for wireless data communication can be significantly reduced using Li-Fi implementation
- Scalable network for enterprise and home applications
- Highly reliable network – chances of device malfunctioning and interference from other sources are lesser compared to the conventional network using radio waves
- Simple implementation – no need for expensive spectrum, equipment, and antenna system
Limitations of Li-Fi
- Device must be compatible – Li-Fi-enabled devices are required to configure the network
- Any distraction could stop connection (requires line of sight communication)
- Integration and coordination of device manufacturers are required for standardization
Future applications of Li-Fi
- Smart home applications for various appliances
- Wireless solutions for enterprise and offices
- Smart city applications
- Smart transport
- Hospitals and healthcare
- Security applications
- Most important data communication option for future 5G and IoT networks
- Airports and large sporting events
IEEE has approved a draft standard for wireless LAN medium access control and physical layer specifications amendment 7 for light communications in local and metropolitan area networks.
This amendment outlines modifications to the existing PHYs and MAC layer for transparent operation of IEEE 802.11 over wireless light medium. It specifies bidirectional operations in the 800 nm to 1000 nm band with a throughput of 10 Mb/s to 9.6 GB/s and ensures interoperability among solid-state light sources with different modulation bandwidths.
Even though Li-Fi is an efficient, fast, and cost-effective technology, more research and development have yet to be done in this area before we have a flexible solution. Due to the higher demand for high-speed data, many wireless technologies are evolving and emerging. Li-Fi technology also has huge potential due to its efficient and cost-effective nature.