this presentation base on wifi technology.in there i am discuss 21 slide about wifi technology.its most help full in our seminar.

1. BY
NAME-SABIR ALI MOLLAH
ROLL NO.-ECE13407
SUB.-SEMINAR II
SUB.CODE-ECE481
ALIAH UNIVERSITY
Wi-Fi Technology
1
PRESENTATION ON

2. Outlines
 Introduction
 Wi-Fi Standards
 Wi-Fi Network Elements
 How a Wi-Fi Network Works
 Advantages and Limitations of Wi-Fi
 Wi-Fi Security
 Conclusion
 Reference
2

3. INTRODUCTION
• Wireless Technology is an alternative to Wired Technology,
which is commonly used, for connecting devices in wireless
mode.
• Wi-Fi (Wireless Fidelity) is a generic term that refers to the
IEEE 802.11 communications standard for Wireless Local
Area Networks (WLANs).
• Wi-Fi Network connect computers to each other, to the
internet and to the wired network.
• Wi-Fi works on physical and data link layer.

4. THE Wi-Fi TECHNOLOGY
 Wi-Fi Networks use Radio Technologies to transmit &
receive data at high speed :
 IEEE 802.11b
 IEEE 802.11a
 IEEE 802.11g
 IEEE 802.11n

5. IEEE 802.11b
 Appeared 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 devices which
can reduce the transmission speed.
5

6. 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
 Not compatible with 802.11b
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7. 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
 Compatible with ‘b’
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8. IEEE 802.11n
 Introduced in 2009
 Up To 300 feet range
 200 Mbps Speed
 2.4 & 5 GHz radio frequencies
8

9. IEEE 802.11 standard
(cont.)
Network
standard
Maximum
Speed
(Mbps)
Range
(feet)
Frequency
(GHz)
Power
drain
Cost
802.11b 11 100-150 2.4 Moderate Low
802.11a 54 60-100 5 High High
802.11g 54 150-250 2.4 Moderate Moderate
802.11n 200
Up to 300
feet
2.4 & 5 Moderate Moderate
9

10. 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 in the same time to the Internet.
 Safeguards - Firewalls and anti-virus software protect
networks from uninvited users and keep information
secure.
 Wi-Fi cards (Adapters) - They accept the wireless
signal and relay information. They can be internal and
external. 10

11. PCI and USB adapters
PCI adapter USB adapter
11
PCMCIA adapter
(Internal) (External)
For Desktop For Laptop

12. How a Wi-Fi Network Works
 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 can
function within a range of 100 – 150 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.

13. How a Wi-Fi Network Works ?
13

14. WI-FI APPLICATIONS
 Home
 Small Businesses
 Large Corporations & Campuses
 Health Care
 Wireless ISP (WISP)
 Travellers
 Wi-Fi Camera

15. Advantages of Wi-Fi
 No Wires - A truly wireless networking solution.
 No Waiting - Fast, easy deployments.
 No Worries - A wireless networking system that is
secure, easy to manage, and built to grow with you.
 Ease of Installation - Quick, easy setup.
 Security - Many Types Of
Security(WEP,WPA,WPA2)
 Fast data transfer rates
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16. Limitations of Wi-Fi
 Limited range
 Interference from other devices : such as
telephones, microwave ovens.
 High power consumption :making battery life and
heat a concern .
 Data security risks :a huge challenge for Wi-Fi
networks
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17. Basic Wi-Fi Security Techniques
 WEP(Wired Equivalent Privacy) : The original encryption
technique specified by the IEEE 802.11 standard.
 WPA(Wi-Fi Protected Access ): A new standard that
provides improved encryption security over WEP.
 WPA2 : is an improved version of WPA that uses
Advanced Encryption Standard (AES) technology.
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18. Basic Wi-Fi Security Techniques(cont.)
Securing
Method
Encryption Type
Used
Security Level Notes
WEP RC4 encryption
algorithm
Low
No longer used; it is can be
hacked easily
WPA TKIP Protocol High
provides improved
encryption security over
WEP
WPA2 CCMP Protocol Very High
An improved version of
WPA that uses Advanced
Encryption Standard
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19. Conclusion
 Wi-Fi is a simple, cost-effective way to connect to the
Internet, without the need to physically connecting wires.
 In 1997 IEEE drafted the 802.11 standard for wireless
local area networking.
 Hotspot is a geographic area setup in any public
location, and has a readily accessible wireless network.
 Security is a huge challenge for Wi-Fi Networks, many
Security Techniques are used to improve it.
 Wi-Fi Networks have a several limitations that should be
concerned.
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20. REFERENCE
 www.Wi-Fitechnology.com
 www.webopedia.com
 www.wavewireless.com
 www.wikipedia.com
 BOOK
802.11 Wirless Networks:The Definitive Guide
-Matthew Gast
How Does Wifi Works
-Matt Anniss