The document discusses Wi-Fi technology and wireless networking. It describes Wi-Fi standards such as 802.11b, 802.11a, 802.11g, 802.11n and the emerging 802.11ac standard. It explains the basic elements of a Wi-Fi network including access points, Wi-Fi cards, and security measures. It also outlines how Wi-Fi networks function and different topology types including AP-based and peer-to-peer. Finally, it lists applications of Wi-Fi and advantages and disadvantages of the technology.

1. Technology
Presented By-Ravi Shankar
CSE 2nd Year

2. CONTENTS
 Introduction
 Wi-Fi Technologies
 Wi-Fi Architecture
 Wi-Fi Network Elements
 How a Wi-Fi Network Works
 Wi-Fi Network Topologies
 Wi-Fi Configurations
 Applications of Wi-Fi
 Advantages/ Disadvantages of Wi-Fi

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).
 You don't need a license to set up and operate
a wireless network.

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
 IEEE 802.11ac

5. Wi-Fi Standards Comparison
Wifi
Standards
Appearing
Year
Radio
Frequency
Theoretical
Speed
Actual Speed Range
(feet)
Bandwidth Radio
Technolo
gy used
802.11b Late 1999 2.4 GHz 11 Mbps 4-6 Mbps 100 20 MHz
802.11a 2001 5 GHz 54 Mbps 15-20 Mbps 50 20 MHz
802.11g 2003 2.4 GHz 54 Mbps 22 Mbps 100 20Mhz OfDM
802.11n 2009 2.5 GHz/5 GHz 300 Mbps 130 Mbps 50 20/40 Mhz OFDM/MI
MO

6. IEEE 802.11ac
 Next big standard ofWIFI ,
 The standard was developed from 2011 through 2013 and
approved in January 2014.
 According to a study, devices with the 802.11ac specification are
expected to be common by 2015 with an estimated one billion
spread around the world.
 1Gbps speed
 Operate on RF bandwidth (up to 160 MHz)

7. 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 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.

8.  HOW A Wi-Fi NETWORK WORKS?
 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 – 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.

9. Wi-Fi NETWORK TOPOLOGIES
Topology generally means network shape or structure
 AP-based topology (Infrastructure Mode)
 Peer-to-peer topology (Ad-hoc Mode)

10. AP BASED TOPOLOGY
 The client communicate through Access Point.
 BSA-RF coverage provided by an AP.

11. PEER-TO-PEER TOPOLOGY
 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.

12. Wi-Fi APPLICATIONS
 Home
 Small Businesses or SOHO(small office home office)
 Large Corporations & Campuses
 Health Care
 Wireless Internet Service Provider (WISP)
 Travellers

13. ADVANTAGES
 Mobility
 Easy of Installation & Flexibility
 Cheaper on a large scale
 Secure
 Use unlicensed part of the radio spectrum
 Interference
 Degradation in performance
 Limited range
 High power consumption
LIMITATIONS

14. Thanks