Light fidelity(Li Fi)

Presentation Seminar on Li-Fi Technology

The future technology in wireless communications

Sumedh Saraf338/1052

General network scenario

Whether you are using a wireless internet in a coffee shop or mall, competing for bandwidth at a conference or probably stealing it from the guy next door, you often get frustrated because of the low speeds you face.

Present Scenario1.4 Million 5 Billion

Present Scenario

Radio Spectrum is congested but the demand for wireless data doubles each year .Every thing, it seems want to use wireless data but the capacity is drying up.

Issues with radio waves and why should we use Visible Light for Communication

CAPACITY: CAPACITY:

With the increasing number of mobile connections the availability of the spectrum is getting congested.

Light is a readily available form of energy and it covers the major portion of the EM spectrum.

Radio waves form only a small fraction of the entire EM spectrum thus making the problem even worse.

Visible light spectrum is 10000 times more compared to radio wave spectrum.

EFFICIENCY: EFFICIENCY:

For every unit of energy consumed the data transmitted is relatively less.

The data transmission for a unit energy consumption is high in the case of light waves.

The data speeds in the current system can only reach up to a few hundreds of megabits per second.

The data transmission can reach up to gigabits per second thus providing very rich data streaming.

AVAILABILITY: AVAILABILITY:

The availability of the radio waves is yet another major issue now a days.

Light is readily available in every part of the world.

These waves are not much available during the flight travel.

This makes it easy for people in airplanes to work on the internet.

SECURITY: SECURITY:

These radio waves can easily penetrate through the walls, thus letting anonymous users to use the network.

Unlike radio waves light waves cannot penetrate through opaque objects thus providing plenty of network privacy.

This can pose threat if the people with bad intentions start using it.

No other person can share a network unless the owner has permitted them to use it.

ECONOMIC: ECONOMIC:

Due to the limited availability of the radio waves the tariff rates are relatively costlier.

The tariff rates can be very cheap as light waves are a cheap resource.

There can be many transparency issues during the spectrum allocations paving way for many scams like in the case of 2G.

There can be transparency in spectrum allocations due to its cheapness.

WHY ONLY VLCRadio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays

X- Rays

Gamm

a Ray

sCAN IT BE GAMMA RAYS ? NO

GAMMA RAYS ARE RADIOACTIVE AND DANGEROUS FOR HEALTH.

CAN IT BE X-RAYS ? NO

X-RAYS HAVE SIMILAR HEALTH ISSUES

CAN IT BE UV RAYS? NO

UV RAYS ARE HARMFUL FOR OUR SKIN AND CANNOT BE USED FOR LONG DURATION

CAN IT BE INFRARED WAVES ? NO

INFRARED, DUE TO EYE SAFETY REGULATION, CAN ONLY BE USED WITH LOW POWER.

HENCE WE ARE LEFT WITH ONLY THE VISIBLE - LIGHT SPECTRUM.

How can we utilize the benefits offered by the visible spectrum?

Li-Fi(Light Fidelity)

Introduction of Li-Fi Li-Fi is a VLC technology developed by

Dr. Gordon Povey, Prof. Harald Haas and Dr. Mostafa Afghani.

Li-Fi is now a part of the Visible Light Communications(VLC) PAN IEEE 802.15.7standard

These devices are normally used for illumination by applying constant current through the LED

Working of Li-Fi This brilliant idea was first showcased in

a TED Global talk on VLC.

Switching the LEDs ON and OFF gives nice opportunities for transmitting data

Some LEDs and a controller that can code data into those LEDs.

Usage of an array of LEDs for parallel data transmission, or using mixtures of red, green and blue LEDs to alter the light’s frequency.

Theoretical speed of 10 Gbps

Usage of rapid pulses of light to transmit information wirelessly

A LI-FI ENVIRONMENT

Comparison between current and future technologies

POTENTIAL APPLICATIONS OF LI-FI TRAFFIC LIGHTS

INTRINSICALLY SAFE ENVIRONMENT

Airlines

Street Lamps as Access Points

In Radio Frequency Hostile Environments

Common Misconceptions

The lights flicker. You cannot dim the lights. VLC is uni-directional (downlink or broadcast

only). There will be interference from sunlight. Lights need to be on so this is inefficient. You must have line-of-sight. This is a disruptive technology. You need special LEDs VLC is a complex technology It will never work!

ConclusionThe possibilities are numerous and can be explored further. If this technology can be put into practical use, every bulb can be used something like a Wi-Fi hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future. This may solve issues such as the shortage of radio frequency bandwidth and also allow internet where traditional radio based wireless isn’t allowed such as aircraft or hospitals. One of the shortcomings however is that it only work in line of sight.

References http://purevlc.co.uk/top-10-li-fi-myths/ http://

www.ted.com/talks/harald_haas_wireless_data_from_every_light_bulb.html

http://timesofindia.indiatimes.com/home/science/Now-just-light-a-bulb-to-switch-on-your-broadband/articleshow/9713554.cms

http://www.independent.co.uk/news/science/lifi-revolution-internet-connections-using-light-bulbs-are-250-times-faster-than-broadband-8909320.html