wi-fitechnology (1)

8/3/2019 Wi-FiTechnology (1)

1/14

Wi-Fi Technology

By

N.NIRMAL KUMAR P.SUDHEERE-mail ID:[email protected] E-maiID:[email protected]

3rd CSE, ASCET. 3rd CSE, ASCET.

ABSTRACT

If we have a computer network in our home or office, there are several different

ways to connect the computers together.Wi-Fi is the wireless way to handle networking.It is also known as

802.11 networking orwireless networking. The big advantage of Wi-Fi is its simplicity and inexpensive.

we can connect computers anywhere in our home or office without the need for wires. The computers connect

to the network using radio signals and computers can be up to 100 feet or so apart.

Wi-Fi stands for Wireless Fidelity. It is used to define any of the wireless

technology in the IEEE 802.11 specifications. Wi-Fi is a brand originally licensed by the Wi-Fi Alliance

which is a body responsible for promoting the term and its association with various wireless technology

standards.

Wi-Fi was intended to be used for mobile devices and LANs, but is now often

used for internet access. It enables a person with a wireless-enabled computer or personal digital assistant

(PDA) to connect to the internet when in proximity of an access point. Wi-Fi also allows connectivity in peer-

to-peer mode, which enables devices to connect directly with each other.

What makes the new standard so attracting means Wi-Fi is cheap,powerful and

most important it works. A box size of paper back magically distributes broadband Internet to an area of a

football field size. A card no longer than matchbox receives it. The next laptop we buy will probably have Wi-

Fi built in. Wires may soon be power alone.


2/14

A TECHNICAL PAPER

ON

Wi-Fi

Planning to make your Network

Wireless.

SUBMITTED TO:

P.B.R VITS, KAVALI.

FOR

VITS TECHNOFEST-2008

BY

N.NIRMAL KUMAR, P.SUDHEER,E-mail id: E-mail id:

[email protected] [email protected]

3rd CSE, ASCET. 3rd CSE, ASCET.

CONTACT NUMBERS: - +919885884303

+919703362012

AUDISANKARA COLLEGE OF ENGINEERING &TECHNOLOGY

DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING

NH-5, BYPASS ROAD, GUDUR-524101,

NELLORE DISTRICT.


3/14

ABSTRACT

If we have a computer network in our home or office, there are several different

ways to connect the computers together. Wi-Fi is the wireless way to handle networking. It is also known as

802.11 networking orwireless networking. The big advantage of Wi-Fi is its simplicity and

inexpensive. We can connect computers anywhere in our home or office without the need for wires. The

computers connect to the network using radio signals and computers can be up to 100 feet or so apart.

Wi-Fi stands for Wireless Fidelity. It is used to define any of the wireless

technology in the IEEE 802.11 specifications. Wi-Fi is a brand originally licensed by the Wi-Fi Alliance

which is a body responsible for promoting the term and its association with various wireless technology

standards.

Wi-Fi was intended to be used for mobile devices and LANs, but is now often

used for internet access. It enables a person with a wireless-enabled computer or personal digital assistant

(PDA) to connect to the internet when in proximity of an access point. Wi-Fi also allows connectivity in peer-

to-peer mode, which enables devices to connect directly with each other.

What makes the new standard so attracting means Wi-Fi is cheap, powerful and

most important it works. A box size of paper back magically distributes broadband Internet to an area of a

football field size. A card no longer than matchbox receives it. The next laptop we buy will probably have Wi-

Fi built in. Wires may soon be power alone.

ContentsContents


4/14

OfOfWi-FiWi-Fi

INTRODUCTIONINTRODUCTION

What is Wi-Fi?What is Wi-Fi?

Wi-Fi standardsWi-Fi standards

Wi-Fi topologyWi-Fi topology

Wi-Fi architectureWi-Fi architecture

Elements of Wi-Fi networkElements of Wi-Fi network

How Wi-Fi works?How Wi-Fi works?

Wi-Fi securityWi-Fi security

AdvantagesAdvantages

LimitationsLimitations

ConclusionConclusion

ReferencesReferences


5/14

1. INTRODUCTION

What is Wi-Fi

. Wi-Fi is acronym for wireless fidelity. Wi-Fi (also WiFi, wifi, etc.) is a brand originally licensed by

the Wi-Fi Alliance to describe the underlying technology of wireless local area networks (WLAN) based on

the IEEE 802.11 specifications. Wireless Technology is an alternative to Wired Technology, which is

commonly used, for connecting devices in wireless mode. It was developed by Kye Brown to be used for

mobile computing devices, such as laptops, in LANs, but is now increasingly used for more services, including

Internet and VoIP phone access, gaming, and basic connectivity of consumer electronics such as televisions

and DVD players, or digital cameras. More standards are in development that will allow Wi-Fi to be used by

cars in highways in support of an Intelligent Transportation System to increase safety, gather statistics, and

enable mobile commerce.

The term Wi-Fi is a play upon the decades-old term Hi-Fi. Hi-Fi stands for High Fidelity

Hi-Fi is a quality standard that means the reproduction of sound or images is very faithful to the original. The

term High Fidelity is applied to any reasonable quality home music system.

A person with a Wi-Fi enabled device such as a computer, cellphone or PDA can connect

to the Internet when in proximity of an access point. Wi-Fi also allows connectivity in peer-to-peer mode,

which enables devices to connect directly with each other

2. WI-FI STANDARDS

Wi-Fi Networks use Radio Technologies called IEEE 802.11 standards to

transmit & receive data at high speed. IEEE 802.11 comprised of more than 20 different standards each of

which is denoted by a letter appended to the end of the name. Vic Hayes who was the primary inventor of

WiFi and has been named the father of WiFi was designed these standards. The most familiar standards are:

IEEE 802.11b

IEEE 802.11a

IEEE 802.11g

The standards 802.11b and 802.11g are used in the majority of commercial Wi-Fi devices.

Both of these standards operate in the 2.4GHz band, and the only major difference between the two is the

transfer rate.


6/14

Comparison of standards: The below table provides a brief overview of three most popular current 802.11

standards as well as information about the next version of Wi-Fi 802.11n.

Standard FrequencyData Transfer Rate

Typical (Max)Range (indoor)

802.11a 5 GHz 25 (50) Mb/sec about 10 m (30 ft)802.11b 2.4GHz 6.5 (11) Mb/sec 30 m (90 ft)

802.11g 2.4 GHz 25 (54) Mb/sec 30+ m (90+ ft)

802.11n * 2.4 GHz 200 (540) Mb/sec 50m (150ft)

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

Pros of 802.11bLowest cost, signal range is best and is not easily obstructed.

Cons of 802.11b Slowest maximum speed; supports fewer simultaneous users ;appliances may

interfere on the unregulated frequency band.

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

Pros of 802.11afastest maximum speed, supports more simultaneous users, regulated frequencies

prevent signal interference from other devices.

Cons of 802.11ahighest cost, shorter range signal that is more easily obstructed, not compatible with

802.11b

IEEE 802.11g

Introduced in 2003

Combine the feature of both standards (a,b)

100-150 feet range


7/14

54 Mbps Speed

2.4 GHz radio frequencies

Pros of 802.11gFastest maximum speed; supports more simultaneous users

Cons of 802.11gCosts more than 802.11b;appliances may interfere on the unregulated signal

frequency.

3. WI-FI TOPOLOGY

Infrastructure mode

4. WI-FI ARCHITECTURE

The typical Wi-Fi architecture shown below.

A typical Wi-Fi setup contains one or more Access points (APs) and one or more clients. An AP

broadcasts its SSID (Service Set Identifier, "Network name") via packets that are called beacons, which are

usually broadcast every 100 ms. The beacons are transmitted at 1 Mbit/s, and are of relatively short duration

and therefore do not have a significant effect on performance. Since 1 Mbit/s is the lowest rate of Wi-Fi it


8/14

assures that the client who receives the beacon can communicate at least 1 Mbit/s. Based on the settings (e.g.

the SSID), the client may decide whether to connect to an AP. If two APs of the same SSID are in range of the

client, the client firmware might use signal strength to decide which of the two APs to make a connection to.

The Wi-Fi standard leaves connection criteria and roaming totally open to the client.. Since Wi-Fi transmits in

the air, it has the same properties as a non-switched ethernet network.

5. Elements of a WI-FI Network

wireless access point (sometimes called an "AP" or "WAP") serves to join or "bridge" wireless clients to a

wired Ethernet network. Access points centralize all Wi-Fi clients on a local network in so-called

infrastructure" mode. An access point in turn may connect to another access point, or to a wired Ethernet

router. The AP is a wireless LAN transceiver or base station that can connect one or many wireless devices

simultaneously to the Internet. The geographical region covered by one or more access points is called a

hotspot.

wireless access point

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)

Wireless router--

The centerpiece product of many home computer networks is a wireless router. These routers support all home

computers configured with wireless network adapters (see below). They also contain a network switch to

allow some computers to be connected with Ethernet cables. Wireless routers allow cable modem and DSL

Internet connections to be shared

Belkin router

Wireless adapter- A wireless network adapter allows a computing device to join a wireless LAN. Wireless

network adapters contain a built-in radio transmitter and receiver. Each adapter supports one or more of the

802.11a, 802.11b, or 802.11g Wi-Fi standards.
http://compnetworking.about.com/od/wireless/ss/wirelessgear_3.htm


9/14

Wireless Network Adapter

6. HOW WI-FI WORKS

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

The communication across a wireless network is like two-way radio communication.

1. A computers wireless adapter translates data into a radio signal and transmits it using an antenna.

2. A wireless router receives the signal and decodes it. It sends the information to the internet using a physical,

wired Ethernet connection.

The process also works in reverse, with the router receiving information from the Internet, translating it

into a radio signal and sending it to the computers wireless adapter. The radios used for Wi-Fi communication

can transmit and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio

waves back into 1s and 0s.

Adding Wi-Fi To Computers

One of the best things about WiFi is how simple it is.Many new laptops already come with a WiFi

card built in -- in many cases we don't have to do anything to start using WiFi. It is also easy to add a WiFi

card to an older laptop or a desktop PC.

Buy a 802.11a, 802.11b or 802.11g network card. For a laptop, this card will normally be a PCMCIA

card that you slide into a PCMCIA slot on your laptop. Or you can buy a small external adapter and

plug it into a USB port. For a desktop machine, you can buy a PCI card that you install inside the

machine, or a small external adapter that you connect to the computer with a USB cable.

Install the card

Install the drivers for the card

Find an 802.11 hotspot.

Access the hotspot.

Hotspot: a connection point for a WiFi network. It is a small box that is hardwired into the Internet.

The box contains an 802.11 radio that can simultaneously talk to up to 100 or so 802.11 cards
http://compnetworking.about.com/od/wireless/ss/wirelessgear_4.htm


10/14

7. WI-FI SECURITY TECHNIQUES

WiFi hotspots can be open or secure. If we set our router to create an open hotspot, anyone who has

a wireless card will be able to use our signal. To keep our network private we can use one of the following

methods:

Wired Equivalency Privacy(WEP): It uses 64-bit or 128-bit encryption. 128-bit encryption is the more

secure option. Any one who wants to use a WEP enabled network has to know the WEP key, which is

usually a numerical password.

WiFi Protected Access(WPA): It is a step up from WEP and is now part of the 802.11i wireless network

security protocol. As with WEP,WPA security involves signing on with a password.

Media Access Control(MAC): Address filtering is a little different from WEP or WPA. It does not use a

password to authenticate users-it uses a computers physical hardware. Each computer has its own unique

MAC address. MAC address filtering allows only machines with specific MAC addresses to access the

network. We must specify which addresses are allowed when we set up our router. This method is very

secure, but if we want to add a new computer to our network we will need to add the new machines MAC

address to the list of approved addresses.

8. ADVANTAGES

Easy setup & Inexpensive: Wi-Fi network dont require professional installation ,and ,best of all,

there are no holes to drill or wires to run through walls.It allows LANs to be used effectively with out

cabling.

Performance: WiFi allows fast data transfer with transfer speed up to 54Mb/sec. 802.11g is currently

the fastest available Wi-Fi protocol on the market.

Security: As 2006, WAP and WPA2 encryption are not easily crackable if strong passwords are used

Roaming: Wi-Fi networks support roaming, in which a mobile client station such as a laptop computercan move from one access point to another as the user moves around a building or area.

Mobility &Flexibility

9. LIMITATIONS

Security concerns: Though it is very easy to setup WiFi network, securing it requires more effort.


11/14

Wi-Fi access points do not come with encryption straight out of the box, we have to do it from our

computer once the network is up and running.

Interference from other devices: Wi-Fi transmissions take place primarily with in the 2.4GHz

spectrum, making them susceptible to interference from Bluetooth wireless enabled devices, card less

telephones and other household devices.

Lack of support for high-quality media streaming: wireless networks have neither the transfer

speeds nor the consistency to transfer high-definition audio and video files flawlessly.

10. CONCLUSION

It is just the beginning of Wi-Fi. We are starting to see the next phase of the Wi-Fi movement. So Wi-

Fi is expected to become an even bigger and hotter technology for both home and businesses in the years to

come. We can soon expect Wi-Fi networks to emerge in urban areas providing coverage throughout the central

city, lining major highways, and giving travellers network access any time , any where.

.Wired vs Wireless

Wired Wireless

Installationmoderate

difficulty

easier, but beware

interference

Cost less more

Reliability high reasonably highPerformance very good good

Security reasonably good reasonably good

Mobility limited outstanding

If we are very cost-conscious, need maximum performance of your home system, and don't care much

about mobility, then a wired Ethernet LAN is probably right for us. If on the other hand, cost is less of an

issue, we like being an early adopter of leading-edge technologies, and we are really concerned about the task

of wiring our home or small business with Ethernet cable, then we should certainly consider a wireless LAN.Any PC brought in a year becomes the hub of a wireless network. An estimated 99 million people

with Wi-Fi by 2006 according to Gartner. Wires may soon be power alone.

REFERENCES


12/14

1. http://compnetworking.about.com

2. http://www.tcil-india.com

3. www.nbc4i.com/technology

4. http://computer .howstuffworks.com

5. http://www.crutchfieldadvisor .com

6. http://en.wikipedia.org/wiki/Wi-Fi

REGISTRATION FORM
http://compnetworking.about.com/http://www.tcil-india.com/http://www.nbc4i.com/technologyhttp://computer/http://www.tcil-india.com/http://www.nbc4i.com/technologyhttp://computer/http://compnetworking.about.com/


13/14


A National Level Students Technical Paper contest

Student : N. Nirmal kumar

Year & Branch : III CSE

Number Of Authors: 2

Name of the college: Audisankara College of engineering & technology, Gudur.

Email: [email protected]

Phone: 9885884303

Title of the paper : Wi-Fi Technology

Accommodation required : Yes

Declaration :

I here by declare that this paper has not been presented in any other conference

/symposium /contest.

Place : GUDUR

Date : 08-09-2008

Signature of the student

REGISTRATION FORM



14/14

A National Level Students Technical Paper contest

Student : P. Sudheer

Year & Branch : III CSE

Number Of Authors: 2

Name of the college: Audisankara College of engineering & technology, Gudur.

Email: [email protected]

Phone:9703362012

Title of the paper : Wi-Fi Technology

Accommodation required : Yes

Declaration :

I here by declare that this paper has not been presented in any other conference

/symposium /contest.

Place : GUDUR

Date : 08-09-2008

Signature of the student

wi-fitechnology (1)

Documents