2. CONTENTS
Introduction
Historical background
Types of Wimax
What can WIMAX do
How WIMAX work
Working scenario
Advantages
Disadvantages
Applications
Future trends
Conclusion
3. INTRODUCTION
WiMAX is short for Worldwide Interoperability for Microwave
Access, and it also goes by the IEEE name 802.16.WiMAX is a
wireless metropolitan area network (MAN) technology that can
connect IEEE 802.11 (Wi-Fi) .
The WiMAX address the "first-mile/last-mile" connection using
a wireless network and therefore is a broadband wireless access
(BWA) technology.
It can provide a wireless alternative to cable and DSL (Digital
Subscriber Line) for last mile (last km) broadband access.
It is similar to
Wi-Fi in concept, but it is aimed at improving
performance and should permit usage over much greater
distances.
4. HISTORICAL BACKGROUND
There are basically three different options:
1. Broadband access – This is provided by either a DSL
or cable modem. This kind of access is generally used
at homes etc.
limitation: the main problems with broadband access
are that it is pretty expensive and it doesn’t reach all
areas
5. HISTORICAL BACKGROUND
2. Wi-Fi access – In your home, you may have set up a Wi-Fi
router that lets you surf the Web while you lounge with
your laptop. On the road, you can find Wi-Fi hot spots in
restaurants, hotels, coffee shops and libraries.
Limitation : The main problem with WiFi access is that
hot spots are very small, so coverage is sparse.
3. Dial-up access – If you are still using dial-up, chances are
that either broadband access is not available, or you think
that broadband access is too expensive.
6. Types of WIMAX
There are mainly 2 types of WIMAX.
1. Fixed WIMAX
2. Mobile WIMAX
Fixed WIMAX : is developed based on the IEEE 802.16
standard and is optimized for fixed and nomadic
applications in LOS and NLOS environments.
Mobile WIMAX : is based on the IEEE 802.16e standard
and targeted primarily for portable and mobile applications
in NLOS environment.
7. Types of WIMAX
Line-of-sight (LOS):
It is a condition where a signal travels over
the air directly from a wireless transmitter to a wireless
receiver without passing an obstruction.LOS connection is
stronger and more stable . LOS transmission use higher
frequency of rang 66GHZ.
Non-Line-Of-Sight (NLOS)
It a condition where a signal from a wireless
transmitter passes several obstructions before arriving at a
wireless receiver. The signal may be
reflected, refracted, diffracted or scattered.NLOS
transmission use lower frequency range of 2GHZ-11GHZ.
8. WHAT CAN WIMAX DO?
WiMAX operates on the same general principles as WiFi —
it sends data from one computer to another via radio
signals.
A computer equipped with WiMAX would receive data
from the WiMAX transmitting station, probably using
encrypted data keys to prevent unauthorized users from
stealing access.
It will provide the equivalent transfer rates to each user.
9. HOW WIMAX WORKS
In practical terms, WiMAX would operate similar to WiFi
but at higher speeds, over greater distances and for a
greater number of users.
A WiMax system consists of two parts: A WiMax tower and
A WiMax receiver
A WiMAX tower - Similar in concept to a cell-phone tower -
A single WiMAX tower can provide coverage to a very large
area -- as big as 3,000 square miles (~8,000 square km).
A WiMAX receiver - The receiver and antenna could be a
small box or they could be built into a laptop the way Wi-Fi
access is today
12. COMPARISION WITH OTHER
NETWORKS
Wi-Fi is developed
with limited frequency
and for limited range.
Range:100to 30meters.
Freq:2.4 to 5.8 GHZ
But WiMAX is having
wide range and frequency
Range:50km and more
Freq:2 to 11GHZ
13. APPLICATIONS
WiMAX could allow access between anyone within
range of each other ,even in areas without preexisting
physical cable or telephone networks.
WiMAX can operate over a wide range of frequencies
including both licensed and unlicensed bands. Due to
its longer range, it makes more sense for most
applications to operate in licensed bands.
15. ADVANTAGES
Offers cheap voice calls and high speed internet
Ensures a boost for government security
It offer fixed broadband access in urban and suburban
areas where copper quality is poor or unbundling difficult
The technology has been claimed to provide shared data
rates up to 70 Mbit/s, but in practical maximum data rates
between 500kbit/s and 2 Mbit/s
16. DISADVANTAGES
The most common misconception is that WiMAX can offer 70
Mbps in range of 70 miles (113 kilometers) with moving
stations but In practice it is valid only in ideal circumstances
with only one recipient.
Line of sight is needed for more distant connections.
Bad weather conditions such as rain could interrupt the signal.
Multiplied frequencies are used.
WiMAX is a very power-consuming technology and requires
significant electrical support.
High installation and operational cost.
17. CONCLUSION
WiMAX deployment will broaden to cover
markets quality have acted as a brake on extensive high-
speed Internet and voice over broadband. WiMAX has the
potential to do to broadband Internet access what cell
phones have done to phone access. WiMAX could replace
cable and DSL services, providing universal Internet
access.
WiMAX will also be as painless as WiFi --
turning your computer on will automatically connect you
to the closest available WiMAX antenna.
18. REFERENCES
WiMAX/802.16 and 802.20, ABI Research, Q4 2003 Last
Mile Wireless High Speed Market, Skylight
Research, March 2004
Providing Always-on Broadband Access to Underserved
Areas, Alcatel Telecommunication Review (p. 127-132), Q4
2003
WiMAX forum web site: www.wimaxforum.org
IEEE SPECTRUM.
howstaffworks.com
