Wireless Fidelity

P r e s e n t e d B y :

Naila Habib Khan

Introduction

Components of Wi-Fi and its working

IEEE 802.11 Architecture

Advantages and Limitations

Topics

Introduction

What Is WiFi?

The Wi-Fi Alliance

Interoperability

Wi-Fi Technology

The term Wi-Fi is often used as a synonym for wireless LAN(WLAN).

A wireless network uses radio waves, just like cell phones, televisions and radios

do.

Uses high frequency radio waves rather than wires to communicate between

nodes.

Wi-Fi is a generic term that refers to the IEEE 802.11 standard.

What Is Wi-Fi?

A global association of companies, promotes WLAN technology and

certifies products if they conform to certain standards of

interoperability.

Not every IEEE 802.11-compliant device is submitted for certification

to the Wi-Fi Alliance, sometimes because of costs associated with

the certification process.

The Wi-Fi Alliance

It means that products from different companies will work together, so

users don't get locked into a single brand of Wi-Fi products.

Wi-Fi Alliance member companies can submit products for certification.

Wi-Fi CERTIFIED products will contain a logo identifying which features

have been tested and that the product has met all the standards of the

notation.

Interoperability

The Wi-Fi Technology

Year Data Transfer

Frenqency

IEEE 802.11 1997 2 Mbps 2.4 GHzUnregulated

IEEE 802.11b 1999 11 Mbps 2.4 GHzUnregulated

IEEE 802.11a 1999-2000 54 Mbps 5GHzRegulated

IEEE 802.11g 2002-2003 54 Mbps 2.4 GHz

Introduction

Components of Wi-Fi and its working

IEEE 802.11 Architecture

Advantages and Limitations

Topics

Components of Wifi

Access Point

Hot Spot

Wi-Fi cards

Safe guards

The AP is a wireless LAN transceiver or “base station” that can connect

one or many wireless devices simultaneously to the Internet.

Access Point (AP)

Hot Spot

They accept the wireless signal. 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

Wi-Fi cards

How a Wi-Fi Network Works A Wi-Fi hotspot is created by installing an access point to an internet

connection.

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.

It’s a two-way radio communication.

A computer's wireless adapter translates data into a radio signal and

transmits it using an antenna.

A wireless router receives the signal and decodes it. The router sends

the information to the Internet using a physical, wired Ethernet

connection.

The process also works in reverse….

Wi-Fi communication

Topics Introduction

Components of Wi-Fi and its working

IEEE 802.11 Architecture

Advantages and Limitations

IEEE 802.11 Architecture

BSS

ESS

Station Types

Basic Service Set

Extended Service Set

IEEE 802.11 defines three types of stations based on their mobility in a

wireless LAN

No transition mobility-Station is stationary or move only inside a BSS

BSS transition mobility-Station can move from one BSS to another but

confined inside one ESS

ESS transition mobility-station can move from one ESS to another. How

ever there is no guarantee that the communication is continuous during

the move.

Station/Node Types

Topics

Introduction

Components of Wi-Fi and its working

IEEE 802.11 Architecture

Advantages and Limitations

Advantages

Long-Term Cost Savings

Reduced Installation Time

Mobility

Scalability

Easy access to the Internet in public places

Limitations OR Disadvantages

Interference

Degradation in performance

High power consumption

Limited range

Thank You

References

www.howstuffworks.comwww.wikipedia.com