View of “LI-FI (LIGHT-FIDELITY): ANEW PARADIGM IN WIRELESS COMMUNICATION”

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ACCENT JOURNAL OF ECONOMICS ECOLOGY & ENGINEERING

Peer Reviewed and Refereed Journal IMPACT FACTOR: 2.104ISSN: 2456-1037 (INTERNATIONAL JOURNAL) Vol.04,Special Issue 02, 13^th Conference (ICOSD) February 2019, Available Online: www.ajeee.co.in/index.php/AJEEE

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“LI-FI (LIGHT-FIDELITY): ANEW PARADIGM IN WIRELESS COMMUNICATION”

Antriskh Tiwari BCA Student, OKIMR Kota tiwariantrishk@gmail.com

Rahul Gupta

Assistant Professor, OKIMR Kota rahulgupta.ccnp@gmail.com

Abstract- Radio frequency (RF) wave is the backbone of wireless communication which provides mobility to the users but also lacks speed. The theoretical speed claimed by wireless networks using radio waves is 54 mbps for 802.11a/b/g standards and 600 mbps on 802.11n standard. Practically we are not even able to achieve even 20 percent of the theoretical speed. This drew attention of researchers towards a new technology “Light Fidelity” (Li-Fi) which theoretically claims speed up to 28 gbps. Li-Fi is technology which works on “Data through illumination” which is transmission of data by sending it through LED (Light Emitting Diodes) that has velocity faster than the human eye can follow. Li-Fi is the term used to label the first and cheap wireless communication system which is the optical version of Wi-Fi. It has also been it demonstrated that Li-Fi does not required line of sight. Li-Fi network is an auto cell network that has the cell size smaller than the typical radio frequency (RF) femtocell network. It has potential to unlock very high areas of spectral efficiencies. Li-Fi uses multi user MIMO technique in an optical auto call network, which has property that the Intensity Modulation (IM) does not suffer from multipath fading. With the use of LED and photodiodes it is possible to create small low complex transceiver units that enable any LED to act as high speed data transmitter. This article compares Li-Fi technology with Wi-Fi and discuss how former turn out to be a better alternate in wireless transmission. We hope in near future with help of Li-Fi we could be able to achieve very high speed wireless networks.

Keywords: Femtocell, IM, LED, Li-Fi, MIMO, RF, Wi-Fi

1. INTRODUCTION

In modern era there is a lot of dependency on wireless networks. Users in 21^th century use laptop or smart phones to access digital communication. RF wave is backbone of wireless communications bt it lacks speed as compared to wired networks. With tremendous capability of mobility provided by wireless networks the users compromised on speed. Now with too many users on wireless spectrum and careless usage of RF spectrum is lead to scarcity of spectrum. This encouraged researchers toward a new technology Li-Fi which uses light from Light emitting Diodes (LED) as new mode of transmission. The theoretical speed claimed by Li-Fi is 28 gbps which is a substantial enhancement on Wi-Fi. In this article we discussed Li-Fi, compared it with Wi-Fi. This article is divided into 6 sections. Section 2 discusses Li-Fi whereas section 3 discusses Wi-Fi.

Section 4 compares both of them. Section 5 discusses limitations and future scope

of research in Li-Fi. Section 6 concludes the article.

2. Li-Fi (LIGHT-FIDELITY)

Li-Fi is the technology that works on

"Data with Illumination", which transmits data by sending it through LED (Light Emitting Diodes), which has a faster velocity compared to human eye. Data is fed into LED light bulb with signal processing technology. LED bulb lays photo detector data at them from one LED light to another without affecting your access at high non-visible rate. The pulses are interpreted by the receiver in an electrical signal; the electronic signal is then converted into binary data, which is the web content that we consume. LED lights will be networked, so many users can access the data using the same LED light or can take 54 Mbps radio waves for 802.11 A / B / g standards, and 802.11 n standard on 600 Mbps.

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2 Fig. 1 Li-Fi [1]

3. Wi-Fi (WIRELESS- FIDELITY) Wi-Fi is a type of wireless networking technology used to connect to the Internet. Frequency works on Wi-Fi 2.4GHz or 5Ghz.There are many standards of Wi-Fi with different speed and power requirements. The earliest standard was 802.11b, although it is the slowest but least expensive in terms of cost. It was upgraded to 802.11a and 802.11g soon. Both of these standards included the technology to split the radio signal and thus reduce the interference.

The latest standard is 802.11 n, which allows long distance and data throughput.

The speed claimed by 802.11 is 54 and by 802.11n is 600 mbps.

Fig. 2 Wi-Fi [2]

4. LI-Fi Vs Wi-Fi 4.1 Li-Fi:-

 Unlike the radio frequency waves used by Wi-Fi, the lights cannot enter through walls and doors.

This makes it more secure and easy to control access to the network.

 Most remote powered underwater vehicles (ROVs) are controlled by wired connections. The length of their cable-carrying locations is a tough limit on their operational

range, and other possible factors such as the weight and fragility of the cable can be restrictive. Since light travel through water, Li-Fi based communication can provide a lot of mobility. The significant amount of light does not penetrate more than 200 meters. The last 1000 meters, no light enters.

 Data in industrial areas is to be transmitted somewhere, Li-Fi is capable of changing industrial Ethernet such as slip rings(Slip ring is an electromechanical device that allows transmission of electrical and electrical signals in a static rotating structure. When transmitting power or signal), sliding contacts and short cables.

Due to the real-time capacity of Li- Fi (which is often required for automation processes), this is an alternative to common industrial wireless component standards 4.2 Wi-Fi:-

 While cellular networks provide continuous connectivity for a much larger area than Li-Fi, the smart phone is bound to use more than one terrestrial transmitter while using the internet. Smart phones need to consume more energy when using cellular network, and using it for a long time can make them less efficient. On the contrary, smart phones enable Wi-Fi using the radio waves. This requires routers instead of terrestrial transmitters. Since the router is very close to it, the transmission is much faster than the cellular network. Even though users have to compromise with the range of mobility of large distance, but it is much more efficient.

 Wi-Fi plans usually provide high- bundle data, which can be up to 50 gigabytes for a period of one month or more. This means that when you access the Internet through Wi-Fi, there is no limit to the consumption of data. On the other hand, cellular companies provide limited data on your mobile plan and each additional byte is calculated and charged on the caps. Although some providers provide some data for free on a monthly basis, it is usually limited to less than 5-10 gigabytes

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3 and is not basically sufficient for surplus consumption. The ideal way to go about it is to save it and use it when you do not have access to any hotspot.

 A dedicated Wi-Fi connection is usually faster than the fastest mobile network available due to obvious reasons. The difference will

not be clear when reading your email or checking status updates.

However, when you have to stream heavy video files or download a large image using cell network, then you are bound to feel the snag. Use of a hotspot to stream media on your smart phone is always a fast and better option.

Fig. 3 difference between Li-Fi and Wi-Fi [3]

5. LIMITATION & FUTURE SCOPE 5.1 Limitations of Li-Fi:

Theoretically Li-Fi technology looks very promising but still we are not able to achieve major breakthrough in this field.

This section discusses the possible for this:

1. Li-Fi requires a line off site.

2. Access to the Li-Fi channel is limited to devices inside the room.

if the device is installed indoors,

then a receiver will not be able to move.

3. The signal limit is limited by physical constraints. If this is more secure, this limited limitation can be a bit annoying.

4. Without the light source the internet cannot be used. It can limit the places and situations in which Li-Fi can be used.

5. A new infrastructure should be built for Li-Fi

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4 6. It uses visible light, and the light

cannot enter the walls, the signal’s limit is limited by physical barriers.

7. Interference in sunlight signals, which will result in the disruption of the internet.

8. If the equipment is set out, then it will need to deal with changing weather conditions.

9. We rely on the light source for the use of the Internet. If the light source is malfunctioning, then we lose access to the Internet.

5.2 Future Scope of Li-Fi:

A lot of research has to be done if we really want this theory to be successful practically and be sustainably developed in near future. We propose following recommendations which the researchers must look for developing efficient Li-Fi infrastructure:

1. Li-fi transceivers must be developed for outdoors.

2. It dependence on electricity for emitting light is too much. If solar energy could be used as source of energy for providing light source we can obtain better results

3. Penetration power of Li-Fi must be enhanced.

4. Interference of sunlight rays with Li-Fi waves must be minimized.

6. CONCLUSION

The concept of Li-Fi is currently attracting a lot of interest, at because it can offer a real and efficient alternative to radio- based wireless. Li-Fi can provide very high speed data transfer up to 28 gbps as theoretically claimed in lab, which is a remarkable improvement over wi-fi speed which theoretically give 600 mbps in 802.11n standard. As the growing number of people and their equipment reach the saturation in wireless internet due to wastage of RF spread spectrum, so Li-Fi in near future could turn out to be an alternative for high speed wireless internet. In this article we discussed the concept of Li-Fi and compared it with Wi- Fi. The paper covered limitations of Li-Fi and suggested recommendations for elimination of these issues. We hope this article will create interest in researchers to work in this area and provide us with sustainable technology of Li-Fi in near future

REFERENCES

1. Devnathan D. Li-Fi Technology

2. https://www.pinterest.com/dev2448/li-fi- technology/

3. [2]. John Hoang Wi-Fi Technology

4. https://www.pinterest.com/pin/1429893568 99311890/

5. Written By Cisco Cisco Router, Network Switch http://ciscorouterswitch.over- blog.com/2017/02/lifi-vs.wifi-basic-

difference- between-lifi-and-wifi.html