FLASH TRANSFER - FUTURE SHORT RANGE COMMUNICATION

Smart devices everywhere – 26 billion devices will be in IoT by 2020.

RF spectrum is congested and new devices will cause more interference

Cisco mobile data forecast

Future network forecast

bytes

To overcome this spectrum issue, Visible Light Communication (VLC) is being developed.

The spectrum of Visible light is 10,000 times more than the spectrum of RF.

The data transfer rate of VLC is very high. Li Fi – an VLC technology demonstrated by

Dr. Harald Haas in 2011

Why VLC

The spectrum of RF and Visible Light

Visible Light Spectrum 430 THz to 790 THzRF spectrum 3 KHz to 300GHz

Transmits data using light. LED is used as transmitter.

High data rates achieved with DC biased Optical (DCO) OFDM and Spatial Modulation techniques.

Intensity of light modulated at high rate. 10 Gbps Li Fi prototype tested by Sisoft in

2014

Li Fi – Light Fidelity

Fujitsu Laboratories developed a model to

replace QR code scanning with Li Fi

technology. Philips successfully used Li Fi to create

shopping assistant.

In both cases, Fixed LEDs transmits data. Smart phone camera used as receiver. So low bit rate data transfer.

Demonstrated applications of Li Fi

One Smart device to another data transfer

- all devices will have both transmitter and receiver. LED flash in device can be transmitter.

Photodiode has to be added additionally

- photo diode & High data rate LED will make short range high data transfer.(up to 200 Mbps)

Flash transfer- make use of LED flash to transmit huge data unidirectional.

Proposed Model

Transmitter – Commercial Phosphor based white LED

Receiver- low cost photodiode; single photodiode with 1.2Gbps used in OFC. Customized diode for VLC economically

Signal Processing module

Almost analogous to 4G LTE. Therefore, with latest technology chip size in Nano meters

Specification for modules

Data transfer between two devices

Advantages

Large bandwidth – around 100 MHz here High Data rate Secure connection – user can see the range

& light won’t penetrate wall No delay for connection as there will be no

need for authentication No harmful radiation

Limitations

Almost Line of Sight transmission Short distance – up to 1 m since the use of

single low power LED Two way Li Fi connection is not viable – at

an instant device can either send or receive

data simplex transmission

Application High speed wireless device to device data

transfer It can transmit large information instantly.

So it can be used as high security pass - a set of (can be billion) security codes.

This type of authentication can be used at ATM Secured Places and Secured internet connection/ computer

Future role of Light

Under Internet of Everything, VLC will

play a vital role. LED lighting is being increased

due to its efficiency.

Our proposed idea will be available in all

smart devices in a decade.

Already Optical communication is backbone

in the form of OFC. Like our proposed short

range communications may create all optical

network.