Wireless_Broadband__Overview_Of_Ieee_802.11_Wireless_Lan_Technology by Ahmad6599

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									Title:
Wireless Broadband: Overview Of Ieee 802.11 Wireless Lan Technology

Word Count:
752

Summary:
Wireless LAN (WLAN) is a wireless broadband technology that utilizes
radio frequency (RF) to transmit and receive data through the air,
minimizing the need for wired networks.

There are two competing RF technologies in the use of Wireless LAN, the
IEEE 802.11 standard and proprietary technologies. Both fall under
wireless broadband technology. Broadband means the ability to transmit
high-speed voice, data and video traffic using a wide range of
frequencies on a single wire...


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Article Body:
Wireless LAN (WLAN) is a wireless broadband technology that utilizes
radio frequency (RF) to transmit and receive data through the air,
minimizing the need for wired networks.

There are two competing RF technologies in the use of Wireless LAN, the
IEEE 802.11 standard and proprietary technologies. Both fall under
wireless broadband technology. Broadband means the ability to transmit
high-speed voice, data and video traffic using a wide range of
frequencies on a single wireless medium or device.

This page aims to give you an overview about Wireless Broadband -IEEE
802.11 standard commonly called Wireless LAN. 802.11 is a standard agreed
by the IEEE (Institute of Electrical and Electronics Engineers, Inc.) the
world's leading professional association for the advancement of
technology. 802.11 is the standard adopted by IEEE to define an over the
air interface between a wireless client and base station or between two
wireless clients.

The 802.11 standard has evolved over the years and became one of the most
successfully deployed technologies. The standard now covers 802.11b,
802.11a and 802.11g systems.

Radio Frequency (RF) is the medium use by wireless networks in the
transmission of information over the air. RF works by converting
electrical current into radio waves and transmit those waves over the air
using a defined frequency of the radio spectrum. An example, the AM and
FM radios two most commonly known uses of the RF spectrum.

The Federal Communications Commission (FCC) is the one administering the
use of radio spectrum between the frequencies of 9 Kilohertz (KHz) and
300 gigahertz (GHz). 802.11 WLAN systems operate in the radio spectrum
available to the public, also known as the unlicensed frequency band.
These radio spectrum bands are unlicensed, free for use by anyone
provided FCC regulations are complied with.

The FCC as a regulatory governs the maximum transmit power of wireless
radios as well as, type of encoding and frequency modulations to be used.
In 802.11 operations, it is provided for by the FCC that non-licensed
radios (such as 802.11) must accept interference from licensed electronic
systems. FCC considers licensed device as the primary equipment.

802.11 Wireless LAN Standard Operating Frequencies: The 802.11 standard
are assigned frequencies 2.4 GHz (2.4-2.4835 GHz) on ISM Band and 5 GHz
(5.15-5.25 GHz, G.25-5.35 GHz, 5.725-5.825 GHz) of the U-NII band.
802.11b and 802.11g operates on 2.4 GHz while 802.11a is operating on the
5 GHz band.

802.11 assigned frequency range has different characteristics. Lower
Frequencies (2.4 GHz ) exhibit better range but with limited bandwidth
and lower data rates. Higher Frequencies (5 GHz) have less range but
higher data rates but is prone to blocking by solid objects.

These are attributable to attenuation and interference. Attenuation or
the loss of signal strength during transmission is higher when the
receiver is farther from the transmitter. Obstacles such as mountains and
buildings also contribute to attenuation by blocking or weakening radio
signals, causing signal loss or dead spots. Depending of what they are
made of, floors, walls, and ceilings can either strengthen or weaken WLAN
signals. Interference can be caused by nearby stations operating in the
same frequency on the same channel. 2.4 GHz cordless phones for instance
can cause great interference on 802.11b wireless networks.

Wireless broadband and WLAN devices are called transceiver devices since
it both transmit and receive at the same time. Each component both
transmits and receives IP traffic. Antennas direct RF power into the air
over a coverage area. An Antenna provides wireless LAN devices gain,
direction and polarization. Gain is the measure of increase in power
while direction is the shape of the transmission pattern. Polarization is
dependent on antenna alignment and can be typically described as vertical
or horizontal. Most Access Point antennas are designed to operate in
vertical pattern for maximum horizontal coverage plane or polarization.
Putting the antenna in a horizontal position will result in a vertical
plane limiting coverage.

The factor to consider in increasing the range of Wireless LAN devices is
the Antenna and EIRP. EIRP or Equivalent Isotropically Radiated Power is
being governed or limited by FCC regulations to a maximum of Four (4)
watts with additional restrictions/limitations depending on type of
antenna (directional or omni-directional) and antenna placement (indoor
or outdoors). Some countries limit EIRP to as much as 100mw, above this
will require a license to operate. This applies mostly for outdoor WLAN
equipments.
To deploy long-range outdoor wireless broadband and WLAN devices, please
consult your country’s telecommunication commission guidelines on use of
outdoor wireless broadband (WLAN) devices.

The goal is to reach people yearning to start their own home-based
business even in remote regions thru cost-effective internet business and
long-range wireless communication solutions.

								
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