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An
Introduction to WiMAX Technology and Testing |
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Worldwide
Interoperability for Microwave Access (WiMAX) digital communications technology
is based on wireless transmission methods defined by the IEEE-802.16 air
interface standard. Intended for wireless metropolitan area networks,
it can provide broadband wireless access with a typical cell radius of
7 -12 km for fixed stations, and 1 - 3 km for mobile stations.
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WiMAX supports data rates up to 75 Mbps over the 2-11 GHz frequency range
using channel bandwidths of 1.25 to 20 MHz and QAM (16QAM or 64QAM) or
QPSK modulation. WiMAX was planned from the beginning to be a carrier-grade
service. Similar to IEEE 802.16 is the European (ETSI) standard HIPERMAN
which is partially based on the same IEEE standards. Besides wired alternatives
such as cable and fibre, wireless alternatives to WiMAX include the new
high-performance 3G wireless standards such as 1xEV-DO and HSPA, and LTE
for the future.
IEEE
802.16 standards address the 2-66 GHz frequency range, but only frequencies
below 6 GHz reliably support non-line-of-sight operations. A large number
of bands are supported by WiMAX in both unlicensed and licensed spectrum,
but the main current focus is on 2.5 GHz and 3.5 GHz for licensed, and
5.8 GHz for unlicensed use.
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The
802.16 air interface standard supports fixed, nomadic, portable and mobile
access (Table 1). To meet the requirements of different types of access,
two versions of WiMAX have been defined. Both fixed and mobile applications
of WiMAX are engineered to help deliver ubiquitous, high-throughput broadband
wireless services at a low cost. |
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Standards
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The
current standard IEEE Std 802.16e-2005 was approved in December 2005,
and follows on from IEEE Std 802.16-2004 (802.16d) which only concerned
fixed systems. 802.16e adds components to the standard for mobility.
IEEE
802.16e-2005 (often refered to as ‘802.16e’ or ‘Mobile
WiMAX’) improves on the modulation schemes defined in the fixed
WiMAX standard, and offers fixed wireless and mobile NLOS (Non Line Of
Sight) possibilities largely thanks to the move to SOFDMA (Scalable Orthogonal
Frequency Division Multiple Access) technology.
For
NLOS use, the enhancements offered over Fixed WiMAX can be attributed
to many features including the following:-
- Improved
coverage by the use of antenna diversity techniques and HARQ (Hybrid
Automatic Repeat Request)
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Use of sub-channelization to improve indoor penetration
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Enhanced security and performance through the use of coding techniques
such as Turbo Coding
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Improved coverage by the use of Adaptive Antenna Systems (AAS) and Multiple
Input Multiple Output (MIMO) technology
Fixed WiMAX is popular
with alternative service providers and operators in developing areas due
to low cost of deployment and advanced performance, and also has the advantage
of currently available products. Fixed WiMax is also a possibility for
backhaul of wireless base stations such as cellular, WiFi and other technologies. |
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| Definition |
Devices |
Location/Speed |
802.16-2004 |
802.16e |
| Fixed
access |
Outdoor
and indoor CPEs |
Single/stationary |
Yes |
Yes |
| Nomadic
access |
Indoor
CPEs, PCMCIA or mini cards |
Multiple/stationary |
Yes |
Yes |
| Portability |
Laptop
PCMCIA or minicards |
Multiple/walking
speed |
No |
Yes |
| Simple
mobility |
Laptop
PCMCIA or minicards, PDAs or smartphones |
Multiple/Low
vehicular speed |
No |
Yes |
| Full
mobility |
Laptop
PCMCIA or minicards, PDAs or smartphones |
Multiple/High
vehicular speed |
No |
Yes |
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Table
1 |
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WiBro
- A broadband wireless internet technology being developed in Korea based
on 100 MHz of spectrum in the 2.3 GHz band allocated by the Korean Government
in Feb’02 for what it called the “portable Internet”.
WiBro provides 30-50 Mbps data throughput with Quality of Service (QoS)
capability. Base stations covering 1-5 km are expected to be widespread,
rather than in localized hotspots like Wi-Fi networks. The Technology Association
of Korea standardized WiBro Phase 1 in late 2004. WiBro has strong backing
from some Korean companies who commenced roll out of WiBro networks in mid-2006'.
'WiBro is now incorporated into 802.16e. |
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WiMAX
On-line Seminars |
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Understanding
WiMAX - This Webinar is designed as an introduction to WiMAX.
Topics include the evolution of the IEEE 802.16 standard, the role of
the WiMAX Forum, and Physical Layer features as they apply to Fixed and
Mobile WiMAX. OFDM will be examined in the frequency domain and OFDMA
will be examined in the time domain. Other topics include the ISI and
the cyclic prefix, and subchannels and permutation zones. View
online seminar
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Base
Station Field Testing and Maintenance
Testing of base stations and wireless networks are increasingly more complicated
with the rapid roll out of new technologies such as CDMA, EVDO, WCDMA, HSDPA
and WiMAX. In this web seminar, you will learn how to simplify your job
by using the latest measurement techniques available today. View
online seminar |
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Deploying
and Testing WiMAX in the Field
Wireline/wireless, DSL, CLEC, and ISP operators are getting ready to deploy
WiMAX networks to offer the best personal broadband experience. In this
webinar, both new and experienced engineers will learn how to save time
by automating measurements with tools from Anritsu. View
online seminar |
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WiMAX
PHY Measurements with the Anritsu Signature High Performance Signal Analyzer
The new mobile WiMAX standard has a new set of requirements for physical
layer (PHY) measurements of modulation quality and interference. This seminar
discusses the complexities of the mobile WiMAX signal, the relevant measures
of modulation quality and interference, and how to make these measurements
with the Anritsu Signature™ High Performance Signal Analyzer. View
online seminar |
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Anritsu
WiMAX Solutions |
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MS269XA Series Signal Analyzers - incorporates a Signal
Analyzer, Signal Generator (optional) and RNC Simulator (optional) in
a hassle free, plug and play, single box solution for next generation
signal analysis. Using an extendable module structure, a range of options
can be added according to your need. The MS2690A and MS2691A are suitable
for use across the mobile market, supporting GSM, GPRS, EDGE, W-CDMA,
WiMAX and HSPA. The MS269X series is also capable of LTE (Long Term Evolution)
and 4G application testing, setting standards for the future of mobile
devices.
Find
out more... |
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MG3700A
Vector Signal Generator - When equipped with the MX370105A
Mobile WiMAX IQproducer application software, the MG3700A can generate
Mobile WiMAX waveform patterns in accordance with the IEEE 802.16e-2005
standard. Key benefits include support for MIMO (Multiple Input, Multiple
Output/Wave 2) waveform patterns, generation of wanted plus interfering
signal or AWGN from one VSG as standard, and optional built-in high-speed
BER test function supporting WiMAX test messages.
Find out more...
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MS2781B
Signature Signal Analyzer - The MS2781B can display a variety
of measurements, including a constellation of a mobile WiMAX signal with
64QAM, 16QAM, and QPSK formats simultaneously, as well as BPSK pilots.
The analyser’s residual Error Vector Magnitude (EVM) for WiMAX signals
is 0.5% (-46 dB). Its demodulation bandwidth of up to 50 MHz supports
capture and analysis of wideband digital modulation, including all WiMAX-specified
bandwidths.
Find
out more... |
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MT8222A
BTS Master - The BTS Master is a single-instrument solution for
engineers, technicians, and contractors responsible for the deployment
of WiMAX networks. The BTS Master can measure the transmitted signal strength
and signal shape of the selected BTS transmission. This WiMAX option includes
familiar channel spectrum, power versus time, ACPR, and RF summary screens.
The Fixed WiMAX Demodulator option analyzes OFDM signals and displays
detailed measurements for evaluating transmitter modulation performance.
Find
out more... |
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MS272XB
Series Handheld Spectrum Analyzer - The MS2721B is designed to
conduct highly accurate analysis on the new wave of wireless LAN and cellular
signals, including 802.11a, 3G, ultra-wideband, WiMAX, and wireless medical
patient monitoring systems. The MS2721B is ideal for AM and FM broadcast
proofing because the wide dynamic range and low phase noise make NRSC
measurements on analog and IBOC signals easy with no need for an external
carrier notch filter. Find
out more... |
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ML2480A
and ML2490A Series Power Meters have a unique combination of
high video bandwidth (20 MHz & 65 MHz) and high sampling rate (64
MS/s and 1 GS/s) providing the accuracy and resolution for measuring the
average, and peak power in WiMAX signal envelope. The
MA249xA series sensors are designed for use with the power meters, for
measuring wideband modulated and CW signals. These sensors have 20 MHz
video bandwidth and 18 ns rise time in the pulse modulated mode.
Find
out more... |
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MS271XB
Series Economy Spectrum Analyzers
- There are now 13 different functional test options available for specific
performance testing of wireless systems, ranging from the hot new wireless
technology of Mobile WiMAX (802.16) to the venerable GSM, and four other
system formats. For each wireless format, there are two options, one for
characterizing the RF signal performance and the other for the modulation
functions. Within any given system format, a long list of test functions
are performed, with displays showing both measured data as well as computed
characterizations. Find
out more... |
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For
more information on WiMAX visit |
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