WI-FI_technology - Copy (2)

7/29/2019 WI-FI_technology - Copy (2)

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Submitted to: Submitted by:Ms. Garima Mathur Rahul Agarwal

HOD, ECE (EC09086)

Jaipur Engineering College,Kukas


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A

PRESENTATION SEMINAR

ON

WI-FI

(Wireless Fidelity)


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CONTENTS Introduction

Wi-Fi Technologies

Wi-Fi Network Elements How a Wi-Fi Network Works

Wi-Fi Network Topologies

Wi-Fi Security

Advantages/ Disadvantages of Wi-Fi

Conclusion

References


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INTRODUCTION

Wi-Fi (Wireless Fidelity) is a generic term that refers to theIEEE 802.11 communications standard for Wireless Local

Area Networks (WLANs).

Wireless Technology is an alternative to Wired Technology ,which is commonly used, for connecting devices in wirelessmode.

Wi-Fi Network connect computers to each other, to theinternet and to the wired network.


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The Wi-Fi Technology Wi-Fi Networks use Radio Technologies to transmit &

receive data at high speed

The name 802.1x comes from the IEEE committee thatstandardized it.

Basic protocols of 802.11 standard are :

IEEE 802.11b

IEEE 802.11a

IEEE 802.11g


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IEEE 802.11b

Appear in late 1999

Operates at 2.4GHz radio spectrum

11 Mbps (theoretical speed) - within 30 m Range 4-6 Mbps (actual speed)

100 -150 feet range

Most popular, Least Expensive

Interference from mobile phones and Bluetooth deviceswhich can reduce the transmission speed.


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IEEE 802.11a Introduced in 2001

Operates at 5 GHz (less popular)

54 Mbps (theoretical speed) 15-20 Mbps (Actual speed)

50-75 feet range

More expensive


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IEEE 802.11g

Introduced in 2003

Combine the feature of both standards (a,b)

100-150 feet range 54 Mbps Speed

2.4 GHz radio frequencies

Use OFDM Technology


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Elements of a WI-FI Network

Access Point (AP) - The AP is a wireless LAN transceiver

or base station that can connect one or many wireless

devices simultaneously to the Internet.

Wi-Fi cards - They accept the wireless signal and relay

information. They can be internal and external. (e.g

PCMCIA Card for Laptop and PCI Card for Desktop PC)

Safeguards - Firewalls and anti-virus software protect

networks from uninvited users and keep information

secure.


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How a Wi-Fi Network Works

Basic concept is same as Walkie talkies.

A Wi-Fi hotspot is created by installing an access point to

an internet connection. An access point acts as a base station.

When Wi-Fi enabled device encounters a hotspot the

device can then connect to that network wirelessly.

A single access point can support up to 30 users and canfunction within a range of 100150 feet indoors and up to

300 feet outdoors.

Many access points can be connected to each other via

Ethernet cables to create a single large network.


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Wi-Fi Network Topologies

AP-based topology (Infrastructure Mode)

Peer-to-peer topology (Ad-hoc Mode)

Point-to-multipoint bridge topology


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AP-based topology

The client communicate through Access Point.

BSA-RF coverage provided by an AP.

ESA-It consists of 2 or more BSA.


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Peer-to-peer TOPOLOGY

AP is not required.

Client devices within a cell

can communicate directly

with each other.

It is useful for setting up of a

wireless network quickly and

easily.


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Point-to-multipoint bridge TOPOLOGYThis is used to connect a LAN in one building to a LANs in

other buildings even if the buildings are miles apart.These

conditions receive a clear line of sight between buildings. The

line-of-sight range varies based on the type of wireless bridge

and antenna used as well as the environmental conditions.


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Open Wireless Access Points

The dangers of open Wi-Fi

A wireless system is like an Internet hub:

Anybody who is within range and has access to the radio

signals is able to see all of the traffic going to and from.

In terms of what the person on an open WiFi network isdoing:

For example email, unless special actions and measures

are taken, email is transmitted as pure raw text in the

clear


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Solutions to open WiFi

Mac Address Filtering

Give my access point a list of allowed clients by their MacAddress

Mac Address Filtering would protect your access point

from a neighbor:

casually connecting or mistakenly connecting


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Solutions to open Wi-Fi

Another possibility:

SSID Hiding

You hide the name of your router so that people don't see it.

It hides it only from those who aren't using packet sniffers,hackers see it just fine.


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Open Wireless Access Points

One Solution

Two common options for encryption:

WEP

WPA

Turn on encryption to scramble your data!


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Solutions to open WiFi One last possibility:

Data Encryption

WEP is one type of encryption

WEP (Wired Equivalent Privacy)

Foundation of WEP encryption is an RC4 cipher, is

extremely strong. But it was used in a very bad way.

Thus WEP is broken!!!


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Solutions to open WiFiWPA Encryption Keys

WPA is a more powerful security technology for Wi-Fi networksthan WEP. It provides strong data protection by using encryption aswell as strong access controls and user authentication. It uses TKIP

encryption.

There are two basic forms of WPA: WPA Enterprise (requires a Radius server)

WPA Personal (also known as WPA-PSK).


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ADVANTAGES

Mobility

Ease of Installation

Flexibility

Cost

Security

Use unlicensed part of the radio spectrum

Roaming

Speed


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LIMITATION

Interference

Degradation in performance

High power consumption

Limited range


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CONCLUSION

For now Wi-Fi provides broad band internet access to

specially outfitted PCs and Laptops. But in future may

be hotspots be wireless.

By Wi-Fi our time and money are saved.

The technologies have help Wi-Fi Hotspots are

becoming more popular throught urban envirnment.


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REFERENCES

www.howstuffworks.com/wireless-network.htm

http://www.wifiplanet.com/tutorials/article.php/3552826

http://www.dslreports.com/faq/11274

www.tatacommunications.com/sme/wifioverview.asp
http://www.howstuffworks.com/wireless-network.htmhttp://www.wifiplanet.com/tutorials/article.php/3552826http://www.dslreports.com/faq/11274http://www.tatacommunications.com/sme/wifi_overview.asphttp://www.tatacommunications.com/sme/wifi_overview.asphttp://www.dslreports.com/faq/11274http://www.wifiplanet.com/tutorials/article.php/3552826http://www.howstuffworks.com/wireless-network.htmhttp://www.howstuffworks.com/wireless-network.htmhttp://www.howstuffworks.com/wireless-network.htm


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THANK YOU


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WI-FI_technology - Copy (2)