coexistence of wifi and lifi

PRESENTED BY:

AVISHEK KUMAR JHAS7 ECE

COEXISTENSE OF WIFI AND LIFI TOWARDS:5G

CONTENTS

• WIFI• LIFI• 5G• COEXISTENCE OF BOTH

INTRODUCTION

• Inter- net-connected mobile devices is rapidly increasing.

• Watching HD streaming videos and accessing cloud-based services

• Heterogeneous networks (HetNets) will play an import- ant role in integrating a diverse spectrum to provide high quality-of-service (QoS)

HETNETS• Hetnets or heterogeneous network• Het- Nets that utilize a combination of

macro cells.• A heterogeneous network is

a network connecting computers and other devices with different operating systems and/or protocols.

• For example, local area network (LANs) that connect Microsoft Windows and Linux based personal computers with Apple Macintosh computes are heterogeneous

WiFi

• WiFi is a technology that allows electronic devices to connect to a wireless LAN(WLAN) network.

• using the 2.4 gigahertz (12 cm) UHF and 5 gigahertz (6 cm) SHF ISM radio bands.

• Commonly used for connecting devices in wireless mode.

Wi-Fi network element

• Access point(AP)- It is a wireless trans receiver which connects one or more devices.

• Wi-Fi cards-They accept wireless signals and relay information .

• Safeguards- Software protect networks from uninvited users.

Advantages of Wi-Fi

• No wires• It is secure and easy to manage.• Ease of installation.• Fast and easy deployments.

Limitation of Wi-Fi

• Limited range.• Data security risk.• Interference from other devices such as

telephones and microwave ovens.

WHAT IS LI-FI?

• Li-Fi, as coined by Prof. Harald Haas during his TED Global talk, is bidirectional, high speed and fully networked wireless communications similar to Wi-Fi. Li-Fi is a subset of optical wireless communication (OWC) and can be a complement to RF communication (Wi-Fi or Cellular network), or a replacement in contexts of data broadcasting

WORKING

COMPARISON

WiFi LiFi

• Speed is about 54Mb/s.

• Use radio waves as carrier.

• LOS is not required

• Less secure.

• Speed is greater than 1Gb/s.

• Use visible light communication.

• Highly secure.

• LOS is highly required.College Of Engineering kuttanad

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• Slow connectivity

• Action of CSMA/CA.

PRIMARY CHALLENGES OF PRESENT WIRELESS

COMMUNICATION

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WHY WiFi AND LiFi TOGETHER ?

80% mobile users are indoor users

LiFi enabled indoor lights modeled as optical-SCs.

Today LiFi enables ONLY downlink. Uplink is still a challenge .

Provides High-speed traffic offloading and security enhancement.

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• How user devices are attached to the n/w?

• How mobility of the device is supported?

• How multiple users are accommodated?

CHALLENGES ON INCORPORATING LiFi AND WiFi

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• More than one luminaire at a sight.

• CSI : Channel State Information

• It is advantage whenever high through-put is required.

• Three possible scenarios:1. Single user provided with single luminaire.2. Single user provided with multiple luminaires.3. Multiple users provided with multiple luminaires.

LINKING UDs TO NETWORK LINKING UDs TO NETWORK

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• Maintaining connectivity for the mobile users is the primary challenge.

• Handover mechanism the traffic from a UD is rerouted from O-SCs to RF-SCs and vice versa.

• Other mechanism: OFDMA(Combined Using Orthogonal Frequency Division Multiple Access).

SUPPORTING UDs MOBILITY SUPPORTING UDs MOBILITY

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• In OFDMA data is transmitted on orthogonal narrow- band subcarriers.

• Users are allocated subcarrier groups to enable concurrent transmission.

LiFi TRANSCEIVERS• In todays world there are LiFi receivers but

not transmitters.

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A Proposed Model Of LiFi Transceiver

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• Si PIN photodiode to provide high speed.• Plano-convex 1”lens are used to

concentrate the beam and enlarge the receiving area.

• BBU(base band unit) is used to convert Ethernet packets into DC-biased OFDM (orthogonal frequency division multiplexing) signals.

• Channel quality and illumination level are the factors that affects the data rate.

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PERFORMANCE OF INDOOR AND OUTDOOR LINKS

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1. Only WiFi is used to connect to internet.

2. Hybrid system – WiFi is used to connect the downlink and uplink along with LiFi as downlink.

3. Aggregate system – user is connected via both LiFi and WiFi system.

COMPARISON OF THREE SYSTEMS

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Hybrid System Aggregate system

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THROUGH PUT V/S DISTANCE

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THROUGHPUT V/S BLOCKAGE DURATION

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• Health sector: Since WiFi alone is not safe to be used in hospitals.

• Internet anywhere: street lamps, light of vehicles can be used to access internet anywhere in footpaths, roads, malls, anywhere where light source is available.

• IoT : Internet of things.

APPLICATIONS

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• Further evolution of LiFi and WiFi to higher data rates.

• Coexistence and further evolution of CSMA/CA and OFDMA.

• Physical layer techniques to enhance the user mobility.

• Improvement and development of the existing optical front ends.

FUTURE

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• Coexistence between LiFi and WiFi is a new promising research area.

• Improved techniques to enable high speed offloading.

• Both technologies together gives triple throughput for individual users.

• There is a great deal of research opportunity for LiFi+WiFi network.

CONCLUSION

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