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NAME: NAME: DDakhara akhara PPradip B radip B ID : 07EC072ID : 07EC072LDRP-ITR LDRP-ITR

GGandhinagarandhinagar

WI-FI

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indexvTYPE OF WIRELESS COMMUNICATION vINTRODUCATION vHISTORY OF WI-FIvWHY WI-FIvTHE WI-FI THECHNOLOGY vElements of a WI-FI NetworkvHow a Wi-Fi Network WorksvTypical Home SetupvWi-Fi Network TopologiesvWIFI StandardsvWhat’s so good about it??vCOMPARISONS 3G VS.WI-FIvWIFI – ApplicationsvWIFI - Advantages

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Type of wireless

Wi-FiBluetoothInfraredGPRSGSM

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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).

• Wi-Fi Network connect computers to each other, to the internet and to the wired network.

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History of WIFI• Wi-Fi stands for Wireless Fidelity protocol, it is a set of

standards for wireless local area network (WLAN)• The IEEE first introduced standard No. 802.11 with

transmissionspeed of 1 and 2 Mbps in the 2.4 GHz band in 1997• Wi-Fi technologies are supported by nearly every modernpersonal computer operating system, most advanced gameconsoles and laptops, and many printers and other

peripherals.• The purpose of Wi-Fi is to provide wireless access to digitalcontent. This content may include applications, audio and

visualmedia, Internet connectivity, or other data. Wi-Fi generallymakes access to information easier, as it can eliminate some

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Why WI‐FIWhy WI‐FIØConvenience: Flexibility of time and locationØMobility: Access the internet even outside their normal work environmentØProductivity: Potentially be moreØDeployment: Requires little more than a single access pointØExpandability: Serve a suddenly increased number of clients

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The Wi-Fi TechnologyWi-Fi Networks use Radio Technologies to

transmit & receive data at high speed:

• IEEE 802.11b• IEEE 802.11a• IEEE 802.11g

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IEEE 802.11b• Appear in late 1999• Operates at 2.4GHz radio spectrum• 11 Mbps (theoretical speed) - within 30 m Range• 4-6 Mbps (actual speed)• 100 -150 feet range• Most popular, Least Expensive• Interference from mobile phones and Bluetooth

devices which can reduce the transmission speed.

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

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IEEE 802.11g• Introduced in 2003• Combine the feature of both standards (a,b)• 100-150 feet range• 54 Mbps Speed• 2.4 GHz radio frequencies• Compatible with ‘b’

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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.

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How a Wi-Fi Network Works• Basic concept is same as Willkie 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.

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Typical Home Typical Home SetupSetup

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Wi-Fi Network Topologies• AP-based topology (Infrastructure Mode)

• Peer-to-peer topology (Ad-hoc Mode)

• Point-to-multipoint bridge topology

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AP-based topology• The client communicate through Access Point. • BSA-RF coverage provided by an AP.• ESA-It consists of 2 or more BSA.• ESA cell includes 10-15% overlap to allow roaming.

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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.

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Point-to-multipoint bridge topologyThis is used to connect a LAN in one building to a LANs in

other buildings even if the buildings are miles apart. These conditions receive a clear line of sight between buildings. The line-of-sight range varies based on the type of wireless bridge and antenna used as well as the environmental conditions

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WIFI Standards In 1999 the first standard was ratified by IEEE to create two

newstandards– 802.11a: OFDM was added in the 5.8 GHz spectrum with

transmissionspeeds of up to 54 Mbps– 802.11b: was added 5.5 and 11 Mbps support using DSSS in

the 2.4 GHzmaking it backward compatible with 802.11• In 2003 the second standard was ratified to create 802.11g– 802.11g: high speed transmission up to 54Mbps by applying

OFDM in the2.4 GHz spectrum– The 802.11g is backward compatible with 802.11b by

integrating DSSSmodulation techniques at 11, 5.5, 2 and 1 Mbps

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What’s so good about it??Wi-Fi allows local area networks (LANs) to bedeployed without cabling for client devices,

typicallyreducing the costs of network deployment andexpansion. Spaces where cables cannot be run,

suchas outdoor areas and historical buildings, can hostwireless LANs.ConvenienceMobility (anytime)Coverage (anywhere)New applications potential (services)Improved quality of life

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WIFI - Applications1. Hotspot Services2. Point-to-Point3. Point-to-Multi Point4. Last-mile5. Hot Zone Service6. Traffic Light7. Dock Area8. Indoor Wi-Fi Extension9. Trucking10. Hi-Speed Mobility11. Fire Alarm12. Wireless Surveillance13. Highway Accident Monitoring14. Wireless Advertisement

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WIFI - Applications

Hotspot ServicesInternetVoIP Phone

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WIFI - Applications

Point-to-Point or Point-to-Multi PointLong distance linkHeadquarter and Branches

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WIFI - ApplicationsLast-mileResidential area

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WIFI - Applications

Hot Zone ServiceInternetVoIP PhoneSurveillance

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WIFI - Applications

Traffic LightEmergency ControlData/Voice/Video

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WIFI - Applications

Dock AreaüData serviceüVoIP PhoneüSurveillance

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WIFI - ApplicationsIndoor Wi-Fi Extension

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WIFI - Applications

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WIFI - ApplicationsWireless Surveillance WIFI

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WIFI - Applications

Highway Accident Monitoring

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IN METRO WI-FI SYSTEM

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WI-FI ON THE HIGHWAY

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coverage area

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The University of Tennessee 26K Students, ~4K faculty/staff at the Knoxville Campus, 1.2M

assignable Sq Meters

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USA spending on municipal wireless networks 3• MuniWireless – October 2006 forecast– $3 billion to 2010 on Muni Wi-Fi in USA alone– 100s of cities in RFP stage, scores in

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WIFI - AdvantagesWi-Fi uses unlicensed spectrumBypassing the need of costly & poor telephone line, it is more

cost effective andmuch easier to deploy It requires much lower cost in the long runs, rather than rely

on Telco’s infrastructureWi-Fi belongs to open International standards, equipments

can be obtainedeasily in the market at very competitive priceWi-Fi offer the freedom to move and supports roamingWi-Fi support various degree of security & encryptionLAN speed performance and obviously broadbandLow cost infrastructure

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THANK YOU