Wireless Fidelity (WiFi)

Wi-Fi (Wireless Fidelity) is a generic term owned by "WiFi Alliance" which refers to any Wireless Local Area Networks (WLANs) based on IEEE 802.11 standard.

This presentation is prepared as reference of "E-Commerce Infrastructure" for BBA 6th Semester Students of Prime College. Document includes general introduction of WiFi Technology, WiFi Specification, advantages of WiFi and so on. Resources from various portals and slides from other authors has been used as reference.

1. Wireless
Technology
HEM SAGAR POKHREL
LECTURER, PRIME COLLEGE
WiFi

2. INSIDE THIS PRESENTATION
Introduction | Wi-Fi Technology
Hotspots
Wi-Fi Network Elements
•Peer to Peer Network
•Infrastructure Network
Wi-Fi Network Topologies
How a Wi-Fi Network Works
WiFi Technology Specifications |
Types
Privacy and Security of WiFi
Basics
Advantages
Limitations

3. Introduction
Wireless,ingeneral,referstoanalternativetoWiredTechnologywhichis
commonlyusedforconnectingdevicesinwireless(withoutwires)mode.
Wirelessbroadbandcandeliverfastinternetspeedbyusingradiowaves
insteadofcablesorwires.
Wi-Fi(WirelessFidelity)isagenerictermthatreferstoIEEE802.11
standardforWirelessLocalAreaNetworks(WLANs).
Wi-FiNetworkconnectcomputingdevicestoeachother,totheinternet
andtothewirednetwork.
ThegoverningbodythatownsthetermWi-FiistheWi-FiAlliancewhich
definesWiFiasanyWLAN(wirelesslocalareanetwork)productsthatare
basedontheInstituteofElectricalandElectronicsEngineers’(IEEE)
802.11standards.

4. Governing Body | WiFi Alliance
Formed in 1999
Founding Companies of WiFi
Alliance are:
Nokia
3Com
Aironet
Harris Semi Conductor
Lucent
Symbol Technologies

5. Introduction | WiFi
Main application of WiFi is to provide highly local wireless radio
links to end user communication equipment such as PCs, VoIP
phones etc.within customer premises/residents.
The latest WiFi products support data rates up to 54 Mbps and
encryption software is used to provide user security.
WiFi “hotspots” are premises such as airport and restaurants
which have set up local WiFi connectivity to the internet.

6. Hotspots
AhotspotisaphysicallocationwherepeoplemayobtainInternet
access,typicallyusingWi-Fitechnology,viaawirelesslocalarea
network(WLAN)usingarouterconnectedtoaninternetservice
provider.-Wikipedia
AHotspotisageographicalareathathasareadilyaccessiblewireless
networkandequippedwithBroadbandInternetconnectionandone
ormoreAccesspointsthatallowuserstoaccesstheinternetwirelessly.
Hotspotscanbesetupinanypubliclocationthatcansupportan
Internetconnection.

7. Elements of a WI-FI Network
AccessPoint(AP)-TheAPisawirelessLANtransceiveror
“basestation”thatcanconnectoneormanywirelessdevices
simultaneouslytotheInternet.
Wi-Ficards-Theyacceptthewirelesssignalandrelay
information.Theycanbeinternalandexternal.
Safeguards-Firewallsandanti-virussoftwareprotectnetworks
fromuninvitedusersandkeepinformationsecure.

8. Wi-Fi Network Topologies
Peer-to-peer
topology (Ad-
hoc Mode)
AP-based
topology
(Infrastructure
Mode)

9. Peer-to-peer topology
Access Point is not required.
Clientdeviceswithinacellcan
communicate witheachother
directly.
Itisusefulforsettingupawireless
networkquicklyandeasily.
Fore.g.Wi-FiDirect

10. Infrastructure network
The client communicate
through Access Point.
Any communication has
to go through AP.
If a Mobile Station (MS), like a computer, a PDA, or a phone, wants to
communicate with another MS, it needs to send the information to AP
first, then AP sends it to the destination MS.

11. How a Wi-Fi Network Works
AWi-Fihotspotiscreatedbyinstallinganaccesspointtoaninternet
connection.
Anaccesspointactsasabasestation.
WhenWi-Fienableddeviceencountersahotspotthedevicecanthen
connecttothatnetworkwirelessly.
Asingleaccesspointcansupportupto30usersandcanfunction
withinarangeof100–150feetindoorsandupto300feetoutdoors.
ManyaccesspointscanbeconnectedtoeachotherviaEthernet
cablestocreateasinglelargenetwork.

12. The Wi-Fi Technology | specifications
Wi-FiNetworksuseRadioTechnologiestotransmitand
receivedataathighspeed:
WiFiSpecifications(basedonIEEE802.11xstandard)
802.11b
802.11a
802.11g

13. Other specifications
802.11 protocols
Source: Wikipedia

14. IEEE 802.11b
Introduced in late 1999
Operates at 2.4GHz radio spectrum.
Speed
11 Mbps (theoretical speed) -within 30 m Range
4-6 Mbps (actual speed)
Range: 100 -150 feet
Most popular, Least Expensive
Interference from mobile phones and Bluetooth
devices which can reduce the transmission
speed.

15. IEEE 802.11a
Introduced in 2001
Operates at 5 GHz (less popular)
Speed:
54 Mbps (theoretical speed)
15-20 Mbps (Actual speed)
Range: 50-75 feet
More expensive
Not compatible with 802.11b

16. IEEE 802.11g
Introducedin2003
Combinethebestfeaturesofbothstandards
(a,b)
Speed:
54MbpsSpeed
2.4GHzradiofrequencies
Range:100-150feet
Compatiblewith802.11b

17. Wi-Fi Security
1.Service Set Identifier (SSID)
2.Wired Equivalent Privacy (WEP)
3.Wireless Protected Access (WPA)
4.MAC Address Filtering
5.IEEE 802.11i
WEPandWPAareencryptionprotocolsthatyoucanchoosefrominyourrouter's
firmware.
Wi-FiProtectedAccess(WPA),asubsetofthenewlyintroduced802.11isecurity
standard,isreplacingtheflawedWiredEquivalentPrivacy(WEP).
WithoutyourSSID,peoplewillnotbeabletojoinyourWi-Fihotspot.

18. WiFi Application Areas
1.Turn Your Smartphone into a Remote Control
2.Send Documents to Your Printer from Any Computer or Smartphone
3.Forward Notifications from Your Smartphone to Your PC
4.Tether Your Smartphone to Your Computer for Internet Anywhere
5.Stream Movies to Any TV in the House
6.Share Files with Nearby Computers
7.Stream Audio to Any Speakers in the House
8.Wirelessly Transfer Photos from Your Digital Camera
9.Tell Your Phone When Its Home (or Not)
10.Sync Your Music Library, Photo Library, or Other Files with Your Smartphone
USB-Free
Source: Lifehacker.com

19. WiFi Advantages
Mobility : Allows users to freely move while using internet.
Ease of Installation
Flexibility: new nodes can be easily added.
Cost : No need of wires and cables
Reliability
Security
Use unlicensed part of the radio spectrum
Speed

20. Other Advantages
ManyelectronicdevicesuseWi-Fiduetoitssimple
functions.
CompaniesuseWi-Fitocreatewirelessnetworks
withintheirboundary.
PhonecompaniessuchasuseWi-FiHotSpotsfor
theiruserstogetfreecalling/internetaccess.
GamingcompanieslikeNintendouseWi-Fitosynch
theirproductsandtouseglobalnetworkusage.
Canbeusedinplacewherecablesarenot
appropriatesuchashistoricbuildingsandmuseums.
CanbeinstalledwhereADSLandcablearenot
available.

21. Limitations/Drawbacks
Degradation in performance
High power consumption
Limited range
Interference: Bandwidth can be limited as WiFi
shares airwaves with devices such as microwave
and cordless phones, which can use up valuable
bandwidth.
Potential security risk: Hackers and Unsecured
WiFi.

22. Finally
Wi-Fi is being a popular, simple and cost effective way
to connect to internet without using any wires.
WiFi technology is growing it’s popularity because of
it’s decreasing costs and the freedom it gives to users.

23. Thanking You !!!
Hem Sagar Pokhrel
Faculty Member
Computer science & IT Department
Prime College –Kathmandu, Nepal
E-mail: [email protected]
Facebook: www.facebook.com/geeksagar
Twitter: www.twitter.com/nepalisagar
LinkedIn: np.linkedin.com/in/geeksagar