Wireless Technology is an alternative to wired Technology, which is commonly devices in wireless mode

1. www.oeclib.in
Submitted By:
Odisha Electronics Control Library
Seminar
On
Wireless Fidelity

2.  Introduction
 Purpose
 Wi-Fi Alliance
 The Wi-Fi Technology
 Elements of a WI-FI Network
 How a Wi-Fi Network Works
 Wi-Fi Network Topologies
 Wi-Fi Configurations
 Wi-Fi Applications
 Wi-Fi Security
 Authentication
 Advantages & Disadvantages
 Conclusion
 References

3. • 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 purpose of Wi-Fi is to hide complexity by
enabling wireless access to applications and data,
media and streams.
The main aims of Wi-Fi are the following:
 make access to information easier
 ensure compatibility and co-existence of devices
 eliminate cabling and wiring
 eliminate switches, adapters, plugs, pins and
connectors

5.  The Alliance promotes standards with the aim of
improving the interoperability of wireless local area
network products based on the IEEE 802.11
standards. The Wi-Fi Alliance, a consortium of
separate and independent companies, agrees on a
set of common interoperable products based on
the family of IEEE 802.11 standards.The Wi-Fi
Alliance certifies products via a set of defined test-
procedures to establish interoperability.

6. 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

7. • 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 devices which can reduce the
transmission speed.

8. • 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

9. • 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’

10. • 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.

11. • 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 can function within a range of 100 up to 300
feet.
• Many access points can be connected to each other
via Ethernet cables to create a single large network.

12. • AP-based topology (Infrastructure Mode)
• Peer-to-peer topology (Ad-hoc Mode)
• Point-to-multipoint bridge topology

13. • The client communicate through Access Point.
• BSA-RF coverage provided by an AP.
• ESA-It consists of 2 or more BSA.
• ESA cell includes 10-15% overlap to allow roaming.

14.  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.

15. This 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.

16. Wi-Fi is composed of three main sectors:
 Home (individual residences and apartment
buildings)
 Public (Round about 70,000 “hotspots”
through out the world.)
 Enterprise (corporations, universities, office
parks)

22. • Home
• Small Businesses or SOHO
• Large Corporations & Campuses
• Health Care
• Wireless ISP (WISP)
• Travellers

23. The requirements for Wi-Fi network security
can be broken down into two primary
components:
• Authentication
• Privacy

24. • Service Set Identifier (SSID)
• Wired Equivalent Privacy (WEP)
•802.1X Access Control
• Wireless Protected Access (WPA)
•IEEE 802.11i

25. • Authentication Server is used
• Username and password
• Risk:
•Data (username & password) send before secure
channel established
• Solution
•Establishing a encrypted channel before
sending username and password

26. • Mobility
• Ease of Installation
• Flexibility
• Cost
• Reliability
• Security
• Use unlicensed part of the radio spectrum
• Roaming
• Speed

27. • Interference
• Degradation in performance
• High power consumption
• Limited range

28.  Wi-Fi provides freedom: freedom to physically
move around your home or business and still stay
connected to the internet or local network; freedom
to grow and move an office or business without
having to install new cables and wires, freedom to
be connected while travelling and on the road .

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