LED light bulbs can now be used to transmit gigabit-level wireless data

Virtually all of the devices we use these days are mobile. Being untethered by nature, the lifeblood of these devices is their ability to access data wirelessly. Until now, wireless data has been facilitated by Bluetooth (for low-speed, short distance wireless communication,) cellular signals (wide range 3G, and soon 4G etc) or WiFi (broadband wireless within rooms, buildings and open areas.)

LED light bulb

But recent developments are pointing to a new-generation technology that uses light–the kind that generic LED bulbs emit–to transmit data at speeds that are anywhere between 10 and 100 times faster than current-generation WiFi. Known as Li-Fi (loosely expanding to Light-Fidelity,) this technology modulates–or changes the intensity of–an LED light causing it to flicker at an imperceptible degree as it transmits a bitstream of digital data.

Using this precisely controlled light modulation, data can be transmitted using regular, visible light. This technology isn’t new–the technology was invented in 2011, during which time scientists achieved data transfer speeds of 224Gbps (that’s a staggering 28 full-length HD-quality movies being transferred, per second.) This is possible due to the massive spectrum available in the visible light range–over 10,000 times that of the radio frequency spectrum, which as we know is already extremely crowded and expensive. LiFi uses multiple streams that result in the ability to simultaneously transmit large amounts of data.

Being based on light, the technology does not work through walls; only line of sight. But this could be construed as an advantage given the inherent security gains of signals being available only where the light falls. Further, the transmission range of this technology is limited compared to a radio frequency based technologies like Wi-Fi.

However the primary applications of the technology involve enabling household appliances and devices to talk to each other, using little more than regular LED light bulbs that are commonly available. The technology could also be used in high-speed point-to-point networking devices that deliver backbone network support. Additionally, these data-laden lights can continue to function for regular illumination, lighting up rooms while continuing to transmit ultra-broadband data.

Commercially available Li-Fi kits are currently available, with initial versions offering transfer speeds of a modest 10Mbps, but this is expected to increase manifold over time.

Know more about the technology from one of its inventors, Harald Haas.