i want seminar report on li fi technology

li fi technology seminar report

Li-Fi, as coined by Prof. Harald Haas during his TED Global talk,[1] is bidirectional, high speed and fully networked wireless communications, like Wi-Fi, using light. Li-Fi is a subset of optical wireless communications (OWC) and can be a complement to RF communication (Wi-Fi or Cellular network), or a replacement in contexts of data broadcasting.

It is wireless and uses visible light communication or infra-red and near ultraviolet (instead of radio frequency waves) spectrum, part of Optical wireless communications technology, which carries much more information, and has been proposed as a solution to the RF-bandwidth limitations.[2] A complete solution includes an industry led standardization process.

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.

The birth of Li-Fi
If you’re an avid follower of TED, you may well have encountered Haas before. Way back in 2011, Haas took to the stage to demonstrate his vision for the future of wireless communications, using little more than LED bulbs. The talk also gave birth to the term ‘Li-Fi’, which is now the commonly used nomenclature for bi-directional, networked wireless communications using visible light, as opposed to traditional radio frequencies.

Light modulation certainly isn’t a new concept, but Haas is looking to move things forward and enable connectivity through simple LED bulbs. With Li-Fi, you can connect to the internet simply by being within range of an LED beam, or you could conceivably transmit data using your car headlights. The ramifications of this are huge, especially with the internet of things in full swing and the much mooted spectrum crunch expected to bite increasingly hard in the coming years.

Researchers at the University of Oxford have reached a new milestone in networking by using light fidelity (Li-Fi) to achieve bi-directional speeds of 224 gigabits per second (Gbps). To put this in perspective, 100Gbps fibre optic core networks have only become a reality in recent years and have yet to become ubiquitous.

Li-Fi is still a long way from being used commercially, but by way of illustration, using a 224Gbps speed would technically allow for 18 movies of 1.5GB each to be downloaded in a single second.

The technology is being developed as a potential alternative to Wi-Fi, and because it uses visible light spectrum to transmit data, when coupled with a high-speed fibre internet connection, researchers believe this can offer speeds far greater than those attained by existing contemporary Wi-Fi technology (600Mbps).

The research, published in the journal Photonics Technology Letter, details how the specialised broadcast LEDs and receivers operate with different fields of view and bands that affect the data transmission speeds.

"The page link operates over ~3 m range at 224 Gb/s (6 x 37.4 Gb/s) and 112 Gb/s (3 x 37.4 Gb/s) with a wide field of view (FOV) of 60° and 36°, respectively. To the best of our knowledge, this is the first demonstration of a wireless page link of this type with a FOV that offers practical room-scale coverage," the report states.

A 'brighter future'

The emerging technology has the potential to provide low-cost wireless internet more securely in localised areas, given that light is unable to pass through walls.

The fastest speed previously achieved using Li-Fi was in October 2014, when a team of researchers from the universities of Oxford, Edinburgh, St Andrews and Strathclyde working on the Ultra-Parallel Visible Light Communications Project reached transmission speeds of 10.5Gbps via Li-Fi.