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Document Body :
WiMAX: A Tutorial
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What is WiMAX
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How WiMAX can be used
for BWA
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Compare WiMAX with WiFi
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Current trends in WiMAX
usage
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References
1. What is WiMAX:
WiMAX is a short name
for Worldwide Interoperability of
Microwave Access. WiMAX is described in IEEE 802.16 Wireless Metropolitan Area
Network (MAN) standard. It is expected that WiMAX compliant systems will provide
fixed wireless alternative to conventional DSL and Cable Internet.
Typically, a WiMAX system consists of two
parts:
- A
WiMAX Base Station: Base station consists of
indoor electronics and a WiMAX tower. Typically, a base station can
cover up to 10 km radius (Theoretically, a base station can cover up to 50
kilo meter radius or 30 miles, however practical considerations limit it to
about 10 km or 6 miles). Any wireless node within the coverage area would be
able to access the Internet.
- A
WiMAX receiver - The receiver and antenna could be a stand-alone box
or a PCMCIA card that sits in your laptop or computer.
Access to WiMAX base station is similar to accessing a Wireless
Access Point in a WiFi network, but the coverage is more.
Several
base stations can be connected with one another by use of high-speed backhaul
microwave links. This would allow for roaming by a WiMAX subscriber from one
base station to another base station area, similar to roaming enabled by
Cellular phone companies.
Important Wireless MAN IEEE 802.16 (WiMAX) Specifications
Range - 30-mile (50-km) radius from base station
Speed - Up to 70 megabits per second
Non-Line-of-sight (NLoS) between user and base station
Frequency bands - 2 to 11 GHz and 10 to 66 GHz (licensed and unlicensed bands)
Defines both the MAC and PHY layers and allows multiple PHY-layer specifications.
2.
How WiMAX can be used for Broadband Wireless Access (BWA):
Typical
areas of application of WiMAX are as given below:
- Residential
and SOHO High Speed Internet Access. The
main contenders for residential and SOHO market are the DSL, and Cable
Internet technologies. These technologies have already established a market
presence, and have proven track record in meeting the demands of the
residential and SOHO customers. WiMAX provides an alternative to existing
access methods, where it is not feasible to use DSL or Cable Internet.
Typical application will be in remote areas where it is not economically
feasible to have a DSL or Cable Internet. WiMAX is also expected to be more
reliable due to wireless nature of communication between the customer
premises and the base station. This is particularly useful in developing
countries where the reliability and quality of land-line communications
infrastructure is often poor.
- Small
and Medium Business. The WiMAX WBA
is well suited to provide the reliability and speed for meeting the
requirements of small and medium size businesses in low density
environments. One disadvantage of WiMAX is the spectral limitation, in other
words limitation of wireless bandwidth. For use in high density areas, it is
possible that the bandwidth may not be sufficient to cater to the needs of a
large clientele, driving the costs high.
- WiFi
Hot Spot Backhaul: Another area
where WiMAX connectivity is for WiFi hot spots connectivity. As of now,
there have been several WiFi hotspots and a WiMAX backhaul provides full
wireless solution to these wireless networks.
3.
Compare WiMAX with WiFi:
The
mail distinction between WiFi and WiMAX is speed and coverage distances. WiFi
has a typical bandwidth of 2MBps whereas WiMAX can have a bandwidth of up to
75MBps. The coverage distances also differ to a great extent. A WiFI hotspot
typically covers a few hundred feet radius (fraction of a kilometer) whereas a
WiMAX can practically cover up to a distance of 10 kilometers (6 miles). One
probable application of MAN is to link several WiFi networks together with WBA
(Wireless Broadband Access) using WiMAX technology.
4.
Current trends in WiMAX usage:
The
technology is relatively new, and several vendors are
coming up with the support infrastructure. Intel and Fujitsu are among
the leading providers of WiMAX compliant SoC chips. The SoCs’ can be used to
make Customer Premise Equipment (CPE) that are used to access WBA base stations.
It is expected that 802.16 compliant systems would be in place by the end of
2005.
5.
References:
http://www.wimaxxed.com/wimaxxed_news/wimax_broadba.html
http://computer.howstuffworks.com/wimax1.htm
http://www.wimaxforum.org/news/downloads/WiMAX-The_Business_Case-Rev3.pdf
Originally
published in www.tutorialsweb.com
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