Experimental Tests for Outage Analysis in SISO Li-Fi Indoor … · 2017-08-30 · Motivation Resources for Testing Test 1 (LOS) Test 2 (LOS) Test 3 (NLOS) Conclusion Experimental

Motivation Resources for Testing Test 1 (LOS) Test 2 (LOS) Test 3 (NLOS) Conclusion

Experimental Tests for Outage Analysis in SISO Li-FiIndoor Communication Environment

Atchutananda Surampudi

The Li-Fi Research Centre,Indian Institute of Technology Madras.

(13:50 - 14:15)Room 7 - Session 3 - Networking

August 28, 2017

Atchutananda Surampudi (I.I.T. Madras) APAN 44, Dalian August 28, 2017 1 / 25


The Presenter

Atchutananda Surampudi,Networks and Stochastic Systems Laboratory,Indian Institute of Technology Madras.(C/O Prof. Radha Krishna Ganti)

Areas of Research

Visible Light Communications, Stochastic Geometry,Interference in Optical Wireless Networks.

Mail

[email protected]



The Li-Fi Project

ERNET - I.I.T. Madras Joint Project.

Team of Professors and Students fromIITM.

This work - One part of project.



Overview of Presentation

1 Motivation

2 Resources for Testing

3 Test 1 (LOS)

4 Test 2 (LOS)

5 Test 3 (NLOS)

6 Conclusion



The IEEE 802.11a - Wi-Fi

The Wireless Internet Access [1].

The Wireless Fidelity (Wi-Fi) usingRadio waves since 1999.

[1] O’hara, Bob, and Al Petrick. IEEE 802.11 handbook: a designer’s companion. IEEEStandards Association, 2005.



The Electromagnetic Spectrum



Why not Visible Light ?



History - The Photophone

Sir Alexander Graham Bell (1880) atthe University Of Edinburgh, U.K [2]

[2] Bell, Alexander Graham. ”The photophone.” Journal of the Franklin Institute 110.4(1880): 237-248.



The Light Fidelity (Li-Fi)

Prof Harald Hass (2011) at theUniversity Of Edinburgh, U.K [3].

[3] Haas, Harald. Harald Haas: Wireless data from every light bulb. TED, 2011.



Things to know about Li-Fi

Downlink − The Internet to user

Uplink − User to the Internet

LED - Transmitter andPhotodiode - Receiver(for both uplink anddownlink)

Energy efficientillumination

High speed data access

Secure Communications

Safe for Humans



The Optical Wireless Channel

Free space optics.

Static and time invariant channel [4].

Fading is absent. Only attenuation.

No Particular analytical theory for outage characterization.

Experimental tests are required

[4] Tsonev, Dobroslav, Stefan Videv, and Harald Haas. ”Light fidelity (Li-Fi): towardsall-optical networking.” Proc. SPIE. Vol. 9007. 2013.



Main Objectives of the work

Downlink performance in Single Input Single Output (SISO).

Tests to characterize outage in LOS and NLOS. Where the outageoccurs, for a given set of parameters ?

Does it work in Non Line of Sight communication ?

Outage

The situation when the Li-Fi Receiver Photodiode is not in theillumination region of the transmitter LED.



The Li-Fi Research Laboratory @ERNET IITM R Park



The Testing Equipments

Component Product Name Quantity

Li-Fi downlink transmitter Luxspace DN561B 1Modem board Modem board 1Xitanium 20W LED power driver LBRD1514-1 1Uplink IR Receiver LBRD14016-3 1Li-Fi Dongel Li-Fi Dongel 1

Table: COMPONENTS : This table shows the Li-Fi communication componentsreceived from The Philips, Eindhoven

NOTE : Exact data sheet values not provided by the Philips.



The System Model (Schematic)

(0, 0)

Receiver Photodiode (PD)

Transmitter LED

(0, h)

h

z

l

θh

(HPSA)θ0,t

θ0,r

θf



The Tests for Outage Characterisation

Test I - Outage using Line Of Sight (LOS) received optical power(w.r.t the Photodiode).

Test II - LOS outage distance on ground (w.r.t the LED).

Test III - Outage in NLOS Communication

Tests are validated using [5].

[5] Lighting, Philips. Lighting manual. Phillips Lighting Company, 1981.



Test I (Line of Sight received optical power)

Fixed - LED at height h, HPSAof LED.

Variable - Position of thePhotodiode over R3, Colour ofthe LED - Red, Blue, Green(RGB).

To Measure - Received OpticalPower or Intensity.



0 50 100 1500

1

2

3

4

5

6x 10

−4

Height in cm

Po

wer in

w

atts

Power received Vs height from source, 0 degree

y = red color

y = green color

y = blue color

y = white color

0 20 40 60 80 100 120 1400

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6x 10

−4

Height in cm

Po

wer in

w

atts


y = red color

y = green color

y = blue color

y = white color



0 20 40 60 80 100 1200

1

x 10−4

Height in cm

Po

wer in

w

atts


y = red color

y = green color

y = blue color

y = white color

5 10 15 20 25 30 350

0.5

1

1.5

2

2.5

3x 10

−5

Height in cm

Po

wer in

w

atts

Power received Vs distance from source, 50 degrees

y = red color

y = green color

y = blue color

y = white color



Test II (Outage distance on Ground)

Fixed - HPSA of LED.

Variable - Height of the LED,Position of the Photodiode overthe ground R2, Colour of theLED - Red, Blue, Green (RGB).

To Measure - Received OpticalPower or Intensity at outage.



40 60 80 100 120 140 160 180 20040

60

80

100

120

140

160

180

Height from ground in cm

Co

vera

ge d

ista

nce in

cm

Coverage distance Vs Source height from ground

y=red color

y=green color

y=blue color

y=white color



Test III (Non Line Of Sight Communication)

(0, 0)

Coloured Reflector

ds

dr

θsθr

LED transmitter

Receiver Photodiode

Fixed - θs = 0 ,θr = 0.

Variable - ds , drand colour ofreflector - Red,Green, Blue,White, Black.

To Measure -Outage distance(dr ,outage).



30 40 50 60 70 80 90 100 110 120 1300

50

100

150

200

250

300

350

400

Distance of source from reflector in cm

Ou

tag

e d

ista

nce in

cm

Outage distance Vs source distance from reflector

y=red reflector

y=green reflector

y=blue reflector

y=white reflector

y=black reflector



In a nut shell..

Advantages

Standard tests to characterisethe optical wireless channel.

Useful in multi LED - multipleuser interference scenario.

Useful for large scale deploymentconstraints and allocation.

Future Work

Improve the tests / standardiseover wider range of Li-Fiproducts.

Non Line of Sight (NLOS) TestIII for θs 6= 0, θr 6= 0.



”Light can change the world.”, Prof. Harald Hass

;Atchutananda Surampudi (I.I.T. Madras) APAN 44, Dalian August 28, 2017 25 / 25

Documents

Experimental Tests for Outage Analysis in SISO Li-Fi Indoor … · 2017-08-30 · Motivation Resources for Testing Test 1 (LOS) Test 2 (LOS) Test 3 (NLOS) Conclusion Experimental