Technology

Presented By-Ravi Shankar

CSE 2nd Year

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

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.

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

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

IEEE 802.11ac

Next big standard of WIFI ,

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)

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.

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.

Wi-Fi NETWORK TOPOLOGIES

Topology generally means network shape or structure

AP-based topology (Infrastructure Mode)

Peer-to-peer topology (Ad-hoc Mode)

AP BASED TOPOLOGY

The client communicate through Access Point.

BSA-RF coverage provided by an AP.

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.

Wi-Fi APPLICATIONS

Home

Small Businesses or SOHO(small office home office)

Large Corporations & Campuses

Health Care

Wireless Internet Service Provider (WISP)

Travellers

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

Thanks