Li-Fi Novel Architecture

8/20/2019 Li-Fi Novel Architecture

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Novel Architecture for Future Li-Fi Wireless Technology

Alif Shah Muhammad Shahzad

Hamdard Institute of Information Technology Pak Datacom Ltd. Islamabad, I-9/2 TIP Building,

Hamdard University Islamabad Campus, Pakistan Islamabad Pakistan

[email protected] [email protected]

Muhammad Wajih Ullah Siddiqi Muhammad Asghar KhanCenter for Advanced Studies in Engineering, CASE Hamdard Institute of Information Technology

Islamabad, Pakistan Hamdard University Islamabad Campus, Pakistan

[email protected] [email protected]

Abstract - L i-F i technology deals with the huge data rate which is

in the range of 150 Mbps to 10 Gbps and uses the visible li ght of

electromagnetic spectrum. This paper pr esents that the Main L ED

Uni t (MLU ) is extended to the Agent LED (AL ) blubs where every

LED bulb has its own L i-F i cloud for the users to access the

internet and other services. The dimension of LED lamp is

presented in two types; one is PP Dimension and the other i s ISD

Dimension . These types of dimensions achi eve the desir ed data rate

for the diff erent applications and services. Th is paper pr esents theidea and technique that how to increase the data rate (R) by

in creasing or decreasing some parameters. The data rate (R) of L i -

F i wi reless technology can be compared with di ff erent parameters

such as size (S) of the LED l ight bul b, numbers (N) of L ED l ight

bulbs in the lamp or source, ON-OFF switching (OOS) of LED

li ght bulbs and dimension of LED l amp.

I ndex Terms – Data Rate, ON-OFF switching, MLU, AL,

Dimension of LED.

I INTRODUCTION

Li-Fi Technology is another milestone in the history

of Wireless Communication and refers to 5G visible light

communication technology. Li-Fi technology deals with thehuge data rate which is in the range of 150 Mbps to 10 Gbps

and uses the visible light of electromagnetic spectrum. There

are some theoretically suggested architectures for Li-Fi [1-2],

which do not cover the architecture and parameters of Li-Fi

wireless technology. In this paper we present idea of Main

LED Unit (MLU) and Agent LED (AL). MLU is extended to

ALs which covers a wide area in terms of light. This paper

also presents the idea and technique that how to increase the

data rate (R) by increasing or decreasing some parameters.

Here it can be concluded that data rate is inversely

proportional to the size of LED. In Li-Fi, data rate can be

increased by increasing the number of LEDs and also

increasing the ON-OFF switching of LED bulb. The size ofnormal LED bulb can be reduced to micro-LED which

handles millions of alterations in light intensity per second and

hence faster the ON-OFF switching and so capable of

transmitting large amount of data at high speed. Micro-LED is

capable to transmit data 1000 times faster than normal LED

with faster ON-OFF switching [1]. The dimensions of the

LED lamp can be of two types; one is Placement and

Positioning (PP) dimension and second is the Internal

Structure Design (ISD) dimension. The PP dimension can be

fixed or movable depends upon the requirements and

implementation. These types of dimension achieve the desired

data rate for different applications and services.

II Li-Fi ARCHITECTURE

In this paper we have presented the idea for novel

architecture of Li-Fi technology which is based on the MLU,

AL and Li-Fi cloud. The MLU is extended to the ALs whereevery AL has their own Li-Fi cloud to provide internet and

other services connectivity through light. In this scenario the

coverage area from a single node spread to the multiple nodes

in the form of agent LEDs (AL). The main line is connected to

the MLU and further it is extended to small nodes which are

LED bulbs or lamps e.g. AL1, AL2, AL3 and AL4. The whole

building is covered by these small nodes and provides wide

coverage through light. The user can access the internet with

little mobility inside the building as shown in figure 1. The

number of ALs depends on the requirements and internal

structure of the buildings.

(a) Dimension of LED Lamp or BulbThe dimension of the LED lamp or bulb can be of two

types.

Placement and Positioning (PP) Dimension

Internal Structure Design (ISD) Dimension

The PP dimension is further divided into two types;

Fixed Position

Movable Position

In Fixed Position, the LED lamp or bulb is fixed inside

the room or building or any other place as shown in figure 2.

The position is adjusted in such a way that it can cover the

maximum area with high intensity of light. The LED lamp or

bulb can be fixed on walls and ceiling of the room or building.The user can access the services and applications of Li-Fi

technology in a fixed area where the LED lamp light can

reach.

In Movable Position, the LED lamp is adjusted in such a

position that it can move with some specific angle and user

can access the services of Li-Fi with low mobility. This type

LED can be used widely because the lamp is moved around a

fixed position, as shown in figure 3. The LED lamp or bulb is

mounted on the walls and ceiling of the room and the direction

http://en.wikipedia.org/wiki/Visible_light_communication






can be changed according to the movement of the Li-Fi users.

If there is a wide angle of movement of the lamp then it can

cover the large area as compared to fixed position.

Fig.1 Novel Architecture of Li-Fi Technology

Fig.2 Li-Fi Cloud

Fig.3 Fixed Position of the LED Lamp

Fig. 4 Movable Position of LED lamp

(b) Internal Structure Design (ISD) Dimension

The ISD dimension is measured with different

parameters such as the diameter and position of the LED lamp.

The ISD depends on the number, size and structure of the

LEDs placed in the lamp. The lamps may be in flat, circular

(round tip) and movable shape. The LEDs are of differenttypes; round tip and chip LEDs are very common as shown in

Fig. 5-7. Both types are used in the lamp for different purposes

in Li-Fi technology. The round tip and circular shape LEDs

are used to focus light on a fixed spot, it means that the data is

transmitted through light towards a fixed point. The chip LED

disperses the light in a wide area with high intensity.

Fig.5 Lamps with different round tip and chip LEDs

Fig.6 Rounded top LED



Fig.7 Chip LEDs, Nano Chip and Pico Chip LEDs

III GOVERNING PARAMETERS

(A)

DATA RATE VERSUS SIZE OF LED

The variations in data rate (R) with the size of LEDs are

very critical in the Li-Fi technology. Different data rates can

be achieved with different sizes of LEDs. The size of normal

LED bulb can be reduced to micro-LED which handles

millions of alterations in light intensity. A micro LED light

bulb to transmit 3.5 Gbps and the data rate of more than 10

Gbps is possible. The tiny micro LED bulbs allow the stream

of light to be beamed in parallel and transmitting huge amount

of data in terms of Gbps. The microchip LED bulb can

generate data rates up to 150 Mbps with single bulb which

provide fast internet connectivity and services. Here it can beconcluded that data rate (R) is inversely proportional to the

size of LED (). The LEDs are of different sizes e.g. 5mm,

3mm, 1.8mm, 1mm, 1m and 1nm LED. The maximum data

rate can be achieved with 1m and 1nm LED which is

considered to be a pixel in size.

R

…………. (i)

(B) DATA RATE VERSUS NUMBER OF LEDs

The data rate can be increased with the increasingnumber of LEDs. The number of LEDs ( ) can be

according to the available space inside the lamp. The number

of LEDs can be adjusted so that it can achieve the maximum

bit rate (bps).

R ……….. (ii)

(C) DATA RATE VERSUS ON-OFF ( ) SWITCHING

OF LED

The ON-OFF switching of LED light bulb can create

binary data of 1s and 0s e.g. 1 for ON and 0 for OFF as shown

in Fig. 8. The micro-LED handles millions of alterations in

light intensity per second and faster the ON-OFF switching,

transmitting large amount of data at high speed. The ON-OFF

switching of LED bulb is at a very high speed so that thehuman eye cannot detect the alterations. Micro-LED is

capable to transmit data 1000 times faster than normal LED

with faster ON-OFF switching, transmitting large amount of

data at high speed.

Fig.8 Data in series of 1s and 0s

The transmitted data is the series of 1s and 0s. For a

large amount of data it is necessary to have a very low

switching time. The ON-OFF is increased by using the OFDM

which enables the micro LED to handle millions of changes inlight intensity per second. Here it can be concluded that the

data rate (R) is directly proportional to the ON-OFF ( )

switching of LED

R ………….. (iii)

(D) R VERSUS , and

We can propose the relation of data rate (R) from the

above given parameters of Li-Fi technology.

R

…………. … (i)

R …………… (ii)R …………… (iii)

Combining the above three equations of data rate;

R

The data rates are calculated with different number, size and

switching of LEDs. The size is reduced from 5mm to 1m, in

case of chip LED, the chip LED is reduced to Nano (n) and



Pico Chip (p). The graphical demonstrations are given in

Fig.9 with different values of Li-Fi

parameters .

Fig.9

The graph shows that Bit rate increases with increase in

number of LEDs and ON-OFF switching. Similarly the Bit

rate increases by decreasing the size of LEDs.

IV CONCLUSION

In this paper we have presented the idea for the

future architecture of Li-Fi technology. The architecture is

explained in terms of MLU, AL, Li-Fi cloud, dimension of

LED lamp and size, number and ON_OFF switching of LEDs

and data rate. The Main LED Unit (MLU) is extended to the

Agent LED (AL) blubs where every LED bulb has its own Li-

Fi cloud for the users to access the internet and other services .

The different types of dimensions and structures of LED and

lamp achieve the desired data rate for the different

applications and services.

Here it can be concluded that data rate can be

increased by decreasing the size of LED bulb, for example the

LED can be reduced from 1mm to 1m for high data rate. The

data rate can also be increased by increasing the number and

ON-OFF switching of LEDs. The data rate is in the range of

150 Mbps to 10 Gbps and can further be increased with some

new up gradation and parameters. All these components and

parameters are the beauty of this novel architecture for future

Li-Fi technology.

REFERENCES

[1] M.Thanigavel M. Tech CSE DEPT GKCE sullperet, AP, India “Li-Fi

Technology in Wireless Communication”, IJERT, ISSN: 2278- 0181,

Vol 2. Issue 10, October 2013

[2] Durgesh Choudhary, Electrical and Electronics Engineering, O. P. Jindal

Institute of Technology, Raigarh-496001,(CG) India, “ Next Generation

Communication for Li-Fi Technology”, International Journal ofEngineering Research & Technology (IJERT). Vol. 2 Issues 11,

November - 2013 IJERT, ISSN: 2278-0181

[3] Krishna Prassad Pujapanda, Veer Surendera Sai, “LiFi Integrated toPower Lines for Smart Illumination cum Communication”, 2013,

International Conference on Communication systems and Network

Technologies.[4] Richard P. Gillard, Marc De Vincentis, Abdeslam Hafidi, Daniel O Hare

and Gregg Hollingsworth “Operation of LiFi Light Emitting Plasma in

Resonant Cavity”. IEEE Transaction on Plasma Science, Vol.39, No.4,April 2011.

[5] http://www.oledcomm.com/

[6] http://www.lificenter.net/solutions/lifi-solution/ [7] http://www.lifi-led.com/

[8] http://en.wikipedia.org/wiki/Li-Fi

[9] www.lificonsortium.org/[10] http://lighting.com/led-lights-lifi/

0 10 20 30 40 50 60 70 80 90 1000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2x 10

9

Number of LEDs

B i t R a t e ( b i t s / s )

Plot of Bit rate vs no. of LEDs at different Sled and Oled

R @ O=1000 & S=0.001

R1 @ O=1000 & S1=0.0005

R2 @ O1=10000 & S1=0.0005

R3 @ O1=10000 & S2=0.00078

R4 @ O2=100000 & S3=0.0100

http://www.oledcomm.com/

http://www.lificenter.net/solutions/lifi-solution

http://www.lifi-led.com/

http://en.wikipedia.org/wiki/Li-Fi

http://www.lificonsortium.org/

http://lighting.com/led-lights-lifi/



http://www.lificonsortium.org/

http://en.wikipedia.org/wiki/Li-Fi

http://www.lifi-led.com/

http://www.lificenter.net/solutions/lifi-solution

http://www.oledcomm.com/

Li-Fi Novel Architecture

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