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IMAGES OF WIRELESS TECHNOLOGIES

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WIRELESS WORLD

WIRELESS TECHNOLOGY simply means that technology giving connections between any two stations at a fixed distance from any fixed reference place without the help of wires.

WIRELESS COMMUNICATION  is the transfer of information

between two or more points that are not connected by an electrical conductor.

The most common wireless technology use electromagnetic wireless telecommunications like radio, television remote control & many othes which can connect to million miles of distance.

“Wireless = Waves” Communicate through Electromagnetic

radiation. Emitted by sinusoidal current running

through a wire (transmitting antenna) Creates propagating sinusoidal magnetic

and electric fields according to Maxwell’s equations:

Fields induce current in receiving antenna

Wave Propagation Example

electricfield

magneticfield

propagation direction

Unlicensed bands. Makes wireless network different from

wired networks. Cost savings over wireline. Can not run wire to locations needed. To enable patrons to bring their own

laptop, therefore reducing the cost of owning many PCs,in case of Wi-Fi.

Why Deploy Wireless?

c

f

Frequency & Public Use Bands

Propagating sinusoidal wave with some frequency/wavelength

C (speed of light) = 3x108 m/s

Name 900 Mhz 2.4 Ghz 5 GhzRange 902 - 928 2.4 - 2.4835 5.15 - 5.35

Bandwidth 26 Mhz 83.5 Mhz 200 Mhz

Wavelength .33m / 13.1” .125m / 4.9” .06 m / 2.4”

Modulation allows the wave to carry information by adjusting its properties in a time varying way◦ Amplitude◦ Frequency◦ Phase

Digital modulation using discrete “steps” so that information can be recovered despite noise/interference.

Modulation

Bluetooth Allows short range(upto 15 mtrs),low

bandwidth communication. Works in 2.4 GHz band. Data rate upto 1 Mbps.

Some Applications :

Wireless Network Card are used. Transmission from Transmitter to Receiver. IEEE Standards 802.11 are used.

Wireless LAN :

Wi-Fi is an abbreviation for Wireless Fidelity and a catch all phrase for the several different standards and recommendations that comprise wireless networking.

Wi-Fi enables the user to deploy a computer network without needing to run cable throughout the facility.

Wi-Fi

GPS units Cellular telephones Satellite Television Two way radios

Other Applications :