This document provides an overview of Wi-Fi technology, including its introduction, scope, working principles, and how to build a Wi-Fi network. Wi-Fi allows for wireless internet and network connectivity within a specific geographic area using radio waves. Common components of a Wi-Fi network include access points that act as base stations to connect wireless devices to the internet or a larger network within a range of 100-150 feet indoors. The document also discusses Wi-Fi security standards like WEP and WPA that aim to protect wireless networks, and examples of Wi-Fi usage in public places and businesses.

1. Presented by WUSL
(2010-2011 batch)

2. Agenda
 Wi-Fi
 Introduction
 Scope of Wi-Fi
 Working principle
 Products
 Building a Wi-Fi Network
 Wi-Fi Security

3. Wireless Fidelity (Wi-Fi)
Welcome to the World of Wireless
A radio technology that networks the devices.
Refers to wireless LAN products based on the IEEE
802.11g specification
Provides easy connections to the internet and
business networks while traveling
The main attractive feature of this technology
is that it can provide wireless broadband
connection within a specific geographic boundary.

4. SCOPE OF Wi-Fi
In few more years all electronic devices are going to
have a built in Wi-Fi..
So once again we welcome to World of wireless.
Many colleges and businesses have suitable
building layouts that can be wireless to build a
unwired network.
Wi-Fi is a very cost effective alternative in these
environments.

5. Operating modes
Infrastructure Mode
AD HOC Mode

6. Building a WiFi
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.

8. Locating Hotspots
There are many Wi-Fi hotspots now
available in public places like
restaurants, hotels, libraries and
airports.
For example, Katunayake Airport,
The number of hotspots in the world is
growing daily.

9. Wi-Fi Topologies
AP Based Topology
Peer to peer Topology
Point to multi-point bridge
Topology

10. AP-based topology
 The client communicates through Access Point.
 It connects the PC’S by an AP.
 It consists of 2 or Base Stations.
 It includes 10-15% overlap to allow roaming.

11.  Access Point 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.

12.  Used to connect a LAN in one building to a
LANs in other buildings even if the buildings
are miles apart.
 Range varies based on the type of wireless
bridge and antenna used as well as the
environmental conditions.

13. Advantages
Can be used in Mobile.
Widely available in public venues.
Relatively inexpensive.
Easy to set up a network.
User-friendly software.
Security features.
Global set of standards.

14. Disadvantages
 Spectrum assignments & operational
limitations
 Power consumption is fairly high
 Degradation in performance
 Networks have limited range
 Used to steal personal and confidential
information

15. Wi-Fi Security
WEP stands for Wired Equivalency Privacy
As its name implies, this standard was intended
to make wireless networks as secure as wired
networks.
The common key lengths are currently 128- and
256-bit.
WPA Wi-Fi Protected Access is an early version
of the 802.11b security standard that was
developed by the Wi-Fi Alliance to replace
WEP.

17. A SPECIAL SECURITY SOFTWARE

18. Wi-Fi Cameras used in BANKS

20. “Things that think…
don’t make sense unless they link.”