Wireless LANs
1
Introduction
• Types of Communication Networks.
• LAN’s Configurations.
• Wireless Technology.
– Definition.
– Applications.
– Example.
• Communications Area.
- Problems:
* Direct Connection of computers.
* Huge Number of connections.
- Solution
* Networking.
2
How it Works
• Brief Introduction.
• Components of
wireless Network.
• Security.
3
Brief Introduction :
• Wi-Fi Network.
• Radio waves.
– Mobile phones, TV and Walkie-Talky.
• Similarities:
– Sending and Receiving.
– Converting 0’s and 1’s.
• Differences:
– Higher Frequencies. 2.4 GHz or 5 GHz
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Components of Wireless Network:
1- Wireless Transmitter (wireless adapter).
PC card slot
USB port
Built-in
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Continued ……..
2- Wireless Router consisting of:
- DSL or Cable port.
- router.
- Ethernet hup.
- Firewall .
- wireless access point.
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* This Network works in the
following way:
- Data  wireless adapter  radio signal 
antenna  wireless router  signals
decoding  Ethernet connection 
information to the internet or other
device.

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Continued…….
• The process also goes in reverse :
Information  router  radio signal
 antenna  adapter  data used
by the computer.

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Security
• Security is an important part of
home wireless network.
• Some precautions or methods should
be used to keep the network private.
- WEP
- WPA
- MAC
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• Wired Equivalency Privacy (WEP):
– WEP key : numerical password .
– Must be known to access the network.
• WIFI Protected Access (WPA):
– Development of WEP .
– Part of 802.11i security protocol.
– Like WEP, it uses a password.
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• Media Access Control (MAC):
- very secure.
– It uses different technology ( Address
Filtering).
– No use of password.
– It uses computer’s physical hardware.
– MAC addresses should be matched in
order to access the network.
- MAC addresses should be added to the
list for new computers.
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Wireless LANs
1] History
2] Standards & protocols
Faisal Nawab
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Why History?
• A way of thinking
• experience
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The beginning of wireless
communication
• Gugliemo Marconi – 1896
• His goal?
• A key to the gate
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Beginning of Wireless
LANs
• Dr. Norman Abramson – 1970s
• Major events since:– 1980: first modems with 9600 bit/s
– 1991: Wireless LAN workshop
(why/results?)
– 1990s: wireless hardware drop
(benefits?)
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ٍStandards and
Protocols
• Why standardization?
• IEEE
• 1990: 802.11 family
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802.11
•
•
•
•
•
802.11: 2Mbps, 2.4GHz
802.11a: 54Mbps, 5Ghz
802.11b: 11Mbps, 2.4GHz
802.11g: 54Mbps, 2.4GHz
IEEE 802.11-2007
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802.11n
• MIMO support
• 500 Mbps
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802.11s
• Mesh networks
• Why?
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Thank you..
Questions?
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