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


• 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


• 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


• 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.


PERFORMANCE OF INDOOR AND OUTDOOR LINKS



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


Hybrid System Aggregate system


THROUGH PUT V/S DISTANCE


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


• 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


• 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
