1. Wireless Networking

2. Wireless Networking Basics
 Wireless networking allows
you to establish:
 Communication using
standard network protocols
and use radio frequency
 Communication without the
use of cables
 Technologies used for
wireless access based on
 Wireless fidelity (Wi-Fi)
 Home Radio Frequency
(HomeRF)

3. Types of Wireless Network – I
• Peer-to-Peer(P2P) or Ad-Hoc
– Connected wirelessly with the use of wireless Network
Interface Card (NIC)
– Computers can access printers and share files
– Wired LAN can be accessed using bridging

4. Types of Wireless Network – II
• Access point or Infrastructure
wireless LAN
– Wireless device connects
to the access point to
connect to the network
– Access point acts as a hub
to connect two wireless
devices
– Wireless bridge used to
connect wireless network
to wired network

5. Wireless Standards
• Variety of standards accepted worldwide and offer different levels of
security
Wireless
Standards
IEEE 802.11 Bluetooth IrDA HomeRF WiMAX

6. IEEE 802.11 – I
• Developed by Institute of Electrical and Electronic
Engineers (IEEE) for defining different aspects of Radio
Frequency Wireless networking
IEEE
802.11
Standards
802.11 802.11a 802.11b 802.11g 802.11n

7. IEEE 802.11 – II
Standard Data Max Frequency Compatibility
Rate range
802.11 2Mbps 46 2.4 GHz 802.11
meter
802.11a 54Mbps 46 5 GHz 802.11a
meter
802.11b 11Mbps 91 2.4 GHz 802.11b
meter
802.11g 54Mbps 91 2.4 GHz 802.11b,
meter 802.11g
802.11n 540 2.4/5 GHz
Mbps

8. IEEE 802.11 – III
• Security
– Four methods of wireless network security:
• Data encryption (WEP and WPA)
• Port based access control
• Service Set Identifier (SSID)
• Media Access Control (MAC) address filtering

9. Security - I
• WEP – suitable for small network
– Uses 64/128 encryption algorithm
– Encryption key is static and shared
– No mechanism for user authentication
WPA – uses dynamic encryption key
user authentication through Extensible Authentication Protocol
(EAP)
SSID – is a 32 character unique identifier
inserted into header of each packet
to secure your network configure your AP with unique SSID
name

10. Security - II
• MAC address filtering – preferred for smaller
network
– MAC address listed in the list can access other
devices in the network
– If any NIC is failed then you have to reconfigure
the AP
Port Based Access control (802.1x) – uses EAP
hardware used such as supplicant, authenticator,
and authenticating server must be 802.1x enabled
to use the network

11. Components Requirements
• The important components required for setting up a
wireless network are:
– Medium
– Access point and Extension point
– Wireless bridges and Power line bridges
– Antennas
– Wireless adapters
– Wireless Station and Server
– Software

12. Medium
• Wireless medium is an unguided form of networking medium
• Wireless transmission involves use of technologies such as
Bluetooth, Infrared, Lasers, Radio signals and Microwave
technologies
• Lasers, infrared and Bluetooth are used mainly in LAN
environment whereas microwave and other radio frequencies
are used to connect vast geographical locations
• Mobile computing allows users to do their work at any
location

13. Access Point and Extension Point
• Access Point
– Device that bridges a wireless connection and a wired
connection
– Two types of access points: Hardware access points and
Software access points
– Generally acts as a hub and operates at layer 1
• Extension Point
– Used if single access point is not able to cover entire
area
– Acts as wireless relay extending the range of wireless
network

14. Hardware Access Points
• Hardware access point is a physical device that is used to
establish a connection between a wired network and a
wireless network

15. Software Access Points
• Software Access Points are computer which includes a
wireless network interface card.

16. Extension Point
• Extension points are used if a single access
point is not able to cover the entire area.

17. Wireless and Power-line bridges
• Wireless bridge  Power-line bridge
– Used to connect two or  Used to penetrate a
more wireless networks wireless network that is
otherwise difficult to
penetrate

18. Antennas and Adapters
• Antennas are used to increase the range of wireless network
• Antennas should be compatible with the router, AP or the
adapter i.e. installed in the network
• Types of antennas used:
– Omnidirectional antennas - Used indoors and small in size
– Directional antennas - High gain and used for long range
outdoor use
• Wireless adapters help to connect computer or PDA to a
network
• Wireless adapters are available as PC cards, PCI and mini PCI,
USB, and CompactFlash.

19. Wireless Station and Server
• Wireless Local Area Network consists of wireless
station and wireless server
• Wireless station - Connects wireless network into a
wireless medium
Wireless Stations
Wireless Clients Access Points
 Wireless server – The main server connected to
the wired network which controls all devices
within the wireless network

20. Software
• Wireless network adapter requires two types of software
so as to function properly:
– Driver
– Configuration Utility
• Windows XP has built-in tools for configuring network
adapter settings
• It is better to use the drivers and configuration utilities
provided by the vendor along with the wireless adapter

21. Application
• Common applications of wireless technologies:
– Wireless Local Area Network (WLAN)
– Wireless Wide Area Network (WWAN)
– Wireless Personal Area Network (WPAN)
– Wireless Metropolitan Area Network (WMAN)
– Mobile Computing

22. Problem Solving
• Wire and Wireless Adapter
– Software Troubleshooting - Wireless adapter configuration
utility and wireless AP’s firmware version
• Driver Compatibility
• Low signal strength – Can be solved with:
– Interference
– Installing repeater
– Changing Antenna
– Installing Window XP Service Pack 2

23. Problem Solving
• Network settings – Common network setting problems
are:
– SSID setting
– DHCP Addresses
– Encryption Keys
– MAC Address Filters