wireless lan poonamk

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Seminar on

Wireless LAN

Presented by

Poonam Kanade

M.E. Electronics & Telecommunication

Terna Engineering College, Nerul.Date:09/03/2012

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.What is Wireless LAN? A wireless local area network (LAN) is a flexible data

communications system implemented as an extension to,

or as an alternative for, a wired LAN.

Using radio frequency (RF) technology, wireless LANs

transmit and receive data over the air, minimizing theneed for wired connections.

Thus, combining data connectivity with user mobility.

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Benefits of Wireless LAN.Installation speed and simplicity

No cable to pull.

Eliminates current architecture obstacles. Few transmitters/receivers for multiple users.

Installation flexibility

The network goes where wires cannot.

Not constrained by expensive walls.

Easy to add more computers and devices.

Reduced cost-of-ownership Mobile devices are less expensive than computer

workstations.

No need to build wiring closets.

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Benefits of Wireless LAN.Mobility Access to real-time information.

Supports productivity.

Provides service opportunities.

Promotes flexibility.

Scalability

Spans a variety of topologies.

Configurations are easily changed.

Works over great distances. Effective for wide range of user communities.

Small number of users with local needs.

Full infrastructure networks roaming over a broad area.

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Practical Use of Wireless LAN.Corporate Mobile networking for e-mail, file sharing, and web

browsing.Education

Connectivity to the University Network for

collaborative class activities.

Ability to access research sources without requiring

a hard point.

Finance

Facilitates electronic payments for goods andservices.

Improve the speed and quality of trades.

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Practical Use of Wireless LAN.Manufacturing Link factory floor workstations to servers.

Remote data collections.

Tracking of goods.

Healthcare

Emergency medical information readily available. Access to schedule information.

Hospitality and Retail

Electronic food orders for pickup or from table.

(Then Pay Electronically)

Check public transportation.

Send notice to hotel of arrival.

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Wireless Network Components.Access Point The access point is a device that links a wireless

network to a wired LAN. It increases the effective range of a wireless network

and provides additional network management and

security features.

Physical model of access point

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Wireless Network Components.PC Card A wireless PC card enables laptop users to connect

wirelessly to the LAN.

Physical model of PC card

PCI Adapter A wireless access PCI adapter allows desktop PC

users access to the LAN.

Physical model of PCI adapter

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Wireless Network Components.Router A router is a device used for sharing a single internet

connection across multiple computers. This is ideal in the home or office where multiple

computers and devices can be online at the same

time with only a single Internet connection.

Physical model of Router

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IEEE Wireless Networking specifications.IEEE 802.11 802.11 protocol is a network access technology for

providing connectivity between wireless stations andwired networking infrastructures.

Allows for interoperability among different vendors

equipment

Specification 802.11

Operated in 2.4GHz

Delivered 1 to 2 Mbps using a technologyknown as phase- shift keying modulation.

This specification is no longer used and has been

replaced by other forms of the 802.11 standard.

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IEEE Wireless Networking specifications.IEEE 802.11a Supplement to 802.11

Operated in 5-6GHz range. Uses Orthogonal Frequency Division Multiplexing

(OFDM) standard

Data transfer rates can be as high as 54Mbps

IEEE 802.11b

Also known as Wi-Fi.

Data transfer rates can be as high as 11Mbps

Uses a technology known as complementary code

keying modulation

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IEEE Wireless Networking specifications.IEEE 802.11g Most recent IEEE 802.11 standard

Operated in 2.4GHz. Uses Orthogonal Frequency Division Multiplexing

(OFDM) standard

Data rates can be as high as 54Mbps over limiteddistance.

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WLAN standard Pros Cons

802.11a

Faster data transfer rates (up to

54Mbps)

Supports more simultaneous

connections

Less susceptible to interference

Short range (60-100 feet)

Less able to penetrate physical

barriers

802.11b

Better at penetrating physical

barriers

Longest range (70-150 feet)

Hardware is usually less

expensive

Slower data transfer rates (up to

11Mbps)

Doesn't support as many

simultaneous connections

More susceptible to interference

802.11g

Faster data transfer rates (up to

54Mbps)

Better range than 802.11a (65-

120 feet)

More susceptible to interference

802.11 Standards Comparison.

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Station1 Station2

Independent Basic Service Set(IBSS)

(ad-hoc/peer to peer)

Ad-Hoc mode. Also known as Independent Basic Service Set (IBSS) or peer-to-peer mode.

All of the computers and workstations connected with a wireless

NIC card can communicate with each other via radio waveswithout an access point.

It is convenient for quickly setting up a wireless network in a

meeting room, hotel conference center, or where sufficient wired

infrastructure does not exist.

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Wireless security.WEP For many wireless users, the enabling of built in

security known as Wireless Equivalent Privacy(WEP).

It is sufficient for home or small to medium office

WLAN.

It encrypts the data transmitted over WLAN.

It uses 64 and 128 bit encryption .

It can be very effective.

Example- business and enterprise users.

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Wireless security.MAC addresses

Media Access Control(MAC) is hardware address that

uniquely identifies each node of the network .

Every network adapter has its unique MAC address.

Wireless security is achieved by strictly specifying

only those addresses that can attach to the network.

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Wireless security.Disable DHCP by default, some access points respond directly to

Dynamic Host Configuration Protocol (DHCP)requests or allow the forwarding of DHCP requests

from clients.

DHCP is a protocol for assigning IP addressesdynamically on a network.

If DHCP enabled on a WLAN, and without proper

security measures enabled, a user can connectautomatically to the network.

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References. Wireless LAN Networking- White Paper , U S Robotics

http://www.pulsewan.com/data101/wireless_lan_basics.htm

Raj Pandya (2003), Mobile and Personal Communication Systems

and Services, Printice Hall of India Pvt. Ltd (Page 168-172).

http://kb.iu.edu/data/aick.html

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THANK YOU

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