Wireless Fidelity: Technology And Applications

8/13/2019 Wireless Fidelity: Technology And Applications

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Wireless Fidelity(Wi-Fi):Technology And ApplicationsPresented by:

Anirban Das

Purboday GhoshSayantan Mitra


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Table of Contents:Introduction

A Brief Historical Background A Basic Wireless LAN Network

Wi-Fi Network Topologies Internationally Accepted Standards of Wi-Fi Advantages Of WifiLimitations Of WifiSecurity And Wifi: An Overview

ApplicationsCostWhere To StartWi-Max: The Next Frontier For Wireless Networks


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Introduction

Wi-Fi is an abbreviation for WirelessFidelity and a catch all phrase for the

several different standards andrecommendations that comprisewireless networking.

Wi-Fi enables the user to deploy acomputer network without needing torun cable throughout the facility.

Wi-Fi: Technology And Applications


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A Brief Historical Background

802.11 technology has its origins in a 1985 ruling bythe US Federal Communications Commission thatreleased the ISM band for unlicensed use. In1991, NCR Corporation with AT&TCorporation invent

ed the precursor to 802.11 intendedfor use in cashier systems. The first wireless productswere under the name WaveLAN.

Vic Hayes has been called the "father of Wi- Fi In 1999, the Wi-Fi Alliance was formed as a tradeassociation to hold the Wi-Fi trademark under whichmost products are sold.The key technologies behind Wi-Fi were developed bythe radio astronomer John O'SullivanThe term Wi-Fi , first used commercially in August1999.The yin-yang Wi-Fi logo indicates the certification of aproduct for interoperability.


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A Basic Wireless LAN Network


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Components Of a WirelessNetwork

Access Points NICs Network Interface Cards

PCMCIA

USBPCICompactFlash

Other Wireless DevicesBridges and RoutersPrint Servers

PCs, Laptops, PDAs


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Components Of A WirelessNetwork(contd..)

Stations A station (STA) is a network node that is equipped with a wirelessnetwork device. A personal computer with a wireless networkadapter is known as a wireless client. Wireless clients cancommunicate directly with each other or through a wireless accesspoint (AP). Wireless clients are mobile.

Wireless APs A wireless AP is a wireless network node that acts as a bridgebetween STAs and a wired network. The wireless AP is similar to acellular phone network's base station. Wireless clientscommunicate with both the wired network and other wirelessclients through the wireless AP.

Ports A port is a channel of a device that can support a single point-to-point connection. A typical wireless AP has multiple ports and cansimultaneously support multiple wireless connections.


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Wi-Fi Network Topologies

Ad-hoc Mode : Peer-to-Peer basedtopology.

Infrastructure Mode : Access Pointbased topology.


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Ad-hoc Mode

Peer-to-peer setupwhere clients canconnect to each otherdirectly. Generally notused for businessnetworks.Its set up for a

special purpose andfor a short period oftime.


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Infrastructure ModeThere is an Access Point (AP),which becomes the hub of a

star topology. Any communication has to gothrough AP. If a MobileStation (MS), like a computer,a PDA, or a phone, wants tocommunicate with another MS,it needs to send theinformation to AP first, then

AP sends it to the destinationMS.Multiple APs can be connectedtogether and handle a largenumber of clients.Used by the majority ofWLANs in homes andbusinesses.

Access Point


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Internationally AcceptedStandards Of Wi-Fi

IEEE has devised a set of universallyaccepted standards for Wi-Fi networks

which are collectively known as the 802.11x Protocol.


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Standards (contd..)Protocol Release

dateFrequency(GHz)

Bandwidth(MHz)

DataRateperStream(Mbit/s)

Range(feet)

802.11a June1997

5 20 Up to 54 50-75

802.11b Sep1999

2.4 20 Up to 11 100-150

802.11g June2003

2.4 20 Up to 54 100-150

802.11n Oct 2009 2.4/5 20/40 Up to72.2 for20 MHz

& 150 for40 MHz

>150


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Comparitive Features Of Various Protocols

802.11b is the most widely used wirelessprotocol.802.11a uses 5GHz Frequency band which is

less crowded than 2.4 GHz band. Hence itallows more channels, reducing radio andmicrowave interference.Cost of 802.11a is more than 802.11b802.11a is not backward compatible with802.11b.802.11g is backward compatible with 802.11band is used in modern laptops.


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Advantages of Wi-FiMobility: Wi-Fi systems can provide LAN users with access to real-time information anywhere in their organization

Installation Speed and Simplicity: Installing a Wi-Fi systemcan be fast and easy and can eliminate the need to pull cable throughwalls and ceilings.

Installation Flexibility: Wireless technology allows the network to gowhere wire cannot go.

Reduced Cost-of-Ownership: Long term cost is lesser than wirednetworks.

Speed: It offers much high speed up to 54 Mbps which is very muchgreater than other wireless access technologies like CORDECT, GSMand CDMA.


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Limitations Of Wi-FiLimited Coverage: 300 ft. effective range from accesspoint.

1400 ft maximum range.

Interference: Structural Interference as well asinterference from other wireless devices.

Security: Wi-Fi Access Points and modems use the WiredEquivalent Privacy (WEP) Standards, which is verysusceptible to hacking and eavesdropping.

Backhaul: Backhaul generally refers to the side of thenetwork that communicates with the global Internet.Backhaul reduces the remaining throughput further.


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Applications Of Wi-Fi

Any application currentlyused on a traditional wirednetwork can be used on awireless network.

New applications may beavailable or can bedeveloped to takeadvantage of wireless,such as Wireless PDAaccess to a card catalog.


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Security And Wi-Fi: An Overview

Wireless networks are inherentlyvulnerable to security breachesand violation of privacy.

Wired Equivalency Privacy(WEP)was the security standard forWLAN.It was succeeded by the firstversion of Wi-Fi Protected Access

(WPA), which uses Temporal KeyIntegrity Protocol (TKIP)encryption and is a step up fromWEP.


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Security(contd)

To keep the network private and secure, one or both ofthe following methods can be used:

Wi-Fi Protected Access version 2 ( WPA2 ) is thesuccessor to WEP and WPA, and is now therecommended security standard for Wi-Fi networks. Ituses either TKIP or Advanced Encryption Standard(AES) encryption, depending upon what you choose atsetup. AES is considered the most secure.

Media Access Control (MAC) address filteringrestricts the number of machines which can connect tothe router based in the hardware MAC address.


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Cost

802.11b Wireless AccessPoints start around $130.00for basic connectivity andrun up to $500.00 for moremanagement features.

802.11b Network InterfaceCards (NICs) cost between$50-$100 and come in USB,PCI, PCMCIA andCompactFlash versions.


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Where to Start

Evaluate the need.

Assess current security andfuture needs.

Assess the environment.

Choose a standard.

Ask for help.


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Wi-Max: The Next Frontier ForWireless Networks

Wi-MAX is an acronym that stands forWorld-wide Interoperability forMicrowave Access and thistechnology is designed toaccommodate both fixed and mobilebroadband applications.

Wi-MAX occupies a somewhat middleground between Wi-Fi and 3Gtechnologies when compared in thekey dimensions of data rate, coverage,QoS(Quality of Service), mobility, andprice.


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Thank You

for yourpatience.

Wireless Fidelity: Technology And Applications

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