Delivering leading solutions for today's field and maintenance challenges |
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With over 20 years leading the way in handheld testing Anritsu has a well earned reputation for superior measurements in not so superior conditions. learn more about the very latest handheld testing technology.
Click the article below to learn more...
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Not All PIM Testers are Created Equal |
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Passive Intermodulation (PIM) is noise generated at a cell site by RF signals passing
through components such as antennas,
filters and RF connections. When PIM falls in
an operator’s receive band, it elevates the
noise floor causing higher dropped call rates,
access failures and lower data transmission
rates. Having PIM under control is especially
important for broadband, high data rate
systems such as UMTS or LTE.
PIM has become more important in recent
years due not only to the growing demand for data services
but also due to increased pressure on operators to deploy
new services using their existing infrastructure. The more
frequency bands that are combined together in a system
the greater the probability that harmful PIM will impact one
or more of the receive bands at that site. Due to aesthetic
restrictions as well as tower loading restrictions, operators
often have no alternative and are forced to combine multiple
bands together in the same infrastructure.
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Another application forcing operators to combine bands
together in a single RF infrastructure is Distributed Antenna
Systems (DAS.) Operators work together with venue owners
to install a single DAS network throughout the building
providing data coverage through a common RF “pipe.” Due
to the large number of RF connections in these systems and
the large number of metal objects in the field of view of the
antennas, PIM is almost a certainty.
When selecting PIM test equipment, it is important to
consider the environment where the test will be conducted.
With the increased usage of Remote Radio Heads (RRH), the
PIM test may need to be conducted at the top of a tower.
Or, with indoor systems, the test equipment may need to
be carried to the top of a ladder in some remote corner
of a building. For these reasons, portability
and battery operation are becoming key
differentiators when considering PIM test
equipment.
Test power is also an important consideration.
Today, most operators specify 2x 43 dBm
(20W) test power for macro site testing in
order to test the system at the same power
level at which RF components are typically
tested by manufacturers. Some operators are
testing at higher powers, such as 2x 46 dBm
(40W), in order to more closely represent the actual
noise levels that can be generated in the field. Similarly,
operators often specify lower test power levels ranging from
2x 33 dBm (2W) to 2x 25 dBm (0.3W) to simulate actual use
conditions within indoor systems. PIM test equipment must
be designed to provide a full range of power adjustment to
suit the system under test.
Distance-to-PIM™ (DTP) technology is another important
differentiator when considering PIM test equipment. DTP
technology provides the distance and relative magnitude
of PIM sources in the system, eliminating guesswork and
speeding site repairs.
The new battery operated PIM Master™ from Anritsu is the
first high power PIM test solution to fully address operator
requirements. This rugged, light weight PIM test analyzer
includes integrated Distance-to-PIM technology as well as
test power adjustment from 25 dBm to 46 dBm. |
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Questions and Answers
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Question: Does Anritsu offer an automated online tool to
simplify line sweep reporting?
Answer: Anritsu offers Sweep Master Pro™, a web application that can dramatically reduce line sweep reporting errors and time. Field technicians save traces with an easily defined naming format, then place the sweeps (or measurement files) into a common directory and log into Sweep Master Pro. Once the files are uploaded, construction managers and/or RF engineers are notified and they can review the data as long as they have Internet access. Files can be created in .zip for .pdf format for storing on a computer or other project tracking systems.
Question: What is the best calibration method – OSL,
InstaCal™, FlexCal™ or OSLT?
Answer: The calibration method is often determined by
the type of test to be conducted. OSL is the most accurate
calibration for one-port tests, such as return loss, VSWR, and
DTF. InstaCal, which can be used with the Site Master™ and
Cell Maser™, is quicker than OSL but is slightly less accurate.
FlexCal can be used for troubleshooting over wide frequency
ranges. OSLT is used for two-port tests.
Question: While making spectrum analysis measurements
on a handheld analyzer with GPS on, is there a way to
display the measurements on a map?
Answer: Spectrum analyzer measurements made using a
BTS Master™ or Spectrum Master™ with the GPS receiver
(option 31) on can be mapped using Master Software Tools,
as long as Microsoft MapPoint is installed in your computer.
After measurements are transferred to your computer,
open the File Menu and click on New. A Measurement Map
selection will automatically open Microsoft MapPoint within
Master Software Tools. Using the Local Tab on the left,
navigate to the folder containing the saved measurements.
Select the measurements and drag them to the (+)
sign at the bottom left corner of the Map screen. All the
measurements will now be displayed on a map. |
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Test Tip |
| Line sweep testing and PIM are very different tests. Line sweeps measure signal losses and reflections of the
transmission system. PIM testing is a measure of construction quality and poor quality will result in self-interference.
Remember, PIM testing measurements are not relevant unless accompanied by comprehensive line sweep tests. |
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Industry’s First High-power, Battery-operated Portable
PIM Test Analyzer |
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Most PIM testing equipment is bulky and requires an AC power source. These attributes are not ideal, considering
more and more cell sites are deployed with radio heads at the top of the tower. Anritsu's PIM Master™
MW82119A, the industry’s first high-power, battery-operated, portable PIM test analyzer, addresses these
issues. One quarter the size and half the weight of alternative PIM test solutions, the MW82119A offers the
inherent advantages of PIM Master – including 40W testing and Anritsu’s
patented Distance-to-PIM (DTP) technology – in a compact housing suited for
difficult-to-access sites, such as RRH installations and indoor DAS.
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Six models are available to address major frequency ranges, including the
upper and lower 700 MHz bands, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and
1900/2100 MHz. All six analyzers incorporate DTP technology, allowing users to
pinpoint the location of PIM problems, whether they are on the tower or outside
the antenna system.
The analyzers also test at 40W, which allows the PIM Master MW82119A
to locate faults that conventional 20W test solutions might miss, such as
intermittent and power-sensitive PIM problems. Plus, the PIM Master has a
flexible power adjustment capability that allows a single MW82119A analyzer
to conduct PIM testing on low-power DAS systems, as well as high-power
Macro Cells. |
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Light Weight, Easy-to-Use Site Master™
Comes in Handy Atop Snowy Mountain |
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Frisco Peak is the highest point in the San Francisco Mountains, making it popular with hikers and
mountain climbers who travel to Utah. However, sitting 9,660 feet (2,944 m) above sea level makes it
one of the more challenging tower sites for Robert Weeks to maintain. Given the altitude – and the fact
that he sometimes has to make the trek in the dead of winter – Robert is glad to have his Site Master
S331D cable and antenna analyzer with him at all times.
The light weight, durability and accuracy of the S331D was
never more advantageous than when Robert had to visit
Frisco Peak to find the cause of a drop in data transmission
rates from the towers in the dead of winter. The environment
was nearly more than a man could take.
"After 8,000 feet, the air became so thin it was hard to catch
my breath. That made a 60-foot climb seem like 1,000 feet,"
Robert said. To make matters worse, when Robert made
this particular trip, snow was being blown around by 40 mph
winds and it was only 10°.
He was able to drive an ATV most of the way, but the final
few miles to the base station had to be logged on foot. It was
during this stretch that Robert particularly appreciated the
compact size of the S331D, as well as when he finally reached
the tower.
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"I had to perform the tower climb as well as trouble shoot,
so the fact that Site Master is a true handheld instrument
was a big plus," he said.
Using his Site Master S331D, Robert conducted system
sweeps and determined the cause of the poor performance
was an azimuth and tilt issue. The problem was fixed and
the tower was back up and working at optimum levels in
relatively short order, thanks in part to the S331D.
"Because it is a quick and easy way to determine fault in
a line, we can perform service calls in a matter of hours
instead of days," he concluded. |
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