User's Manual

PMP 400/430 and PTP 200 Series Canopy User Guide
Supplement
Issue 4 0 – DRAFT 6 November 2009 Page 29 of 64
and, for new equipment, Europe. When the Canopy module is set to either of those regions
(configured on the Configuration => General page of the module), it will not allow configuration of
the appropriate frequencies, as shown in Table 9. Even in regions where use of the spectrum
between 5600 and 5650 MHz is allowed, the best practice is to not use these channels if there
are any other usable channels available. Only use the channels in this “weather notch” after
monitoring the spectrum for a week or more using a spectrum analyzer to ascertain the spectrum
is clear and there is no weather radar in the area that will cause interference to your Canopy
system.
3.4 RANGE AND THROUGHPUT PLANNING
PMP 400/430 and PTP 200 Series modules provide up to 21 Mbps aggregate throughput at
distances of 1.25 mi (~1 km) (1.7 mi for 4.9 GHz systems) in RF environments with clear line-of-
sight and low background interference levels. Additional performance details are shown in Table
7 on page 26. RF environments with occluded Fresnel zones or higher background interference
levels may give lower, but still very good, performance, depending on the specifics of the
environment.
Similar to standard Canopy, at any given instant, any radios operating at 1X or 2X take more “air
time” to transmit a given amount of data than if they were running at 3X. Similar to standard
Canopy, PMP 400/430 and PTP 200 Series modules may see reduced total throughput when
handling traffic with a high percentage of small packets.
The effect of this, again similar to standard Canopy, is that at any given instant total throughput
depends on
• Mix of links running at 3X, 2X, and 1X
• Mix of packet sizes
3.5 SPECTRUM ANALYZER
A spectrum analyzer is available on the SM’s Tools => Spectrum Analyzer page. The spectrum
analyzer is also available on an AP by temporarily converting it to an SM by setting the Device
Type to SM on the AP’s Configuration => General page. The spectrum analyzer works like the
spectrum analyzer in classic FSK SMs.
Spectrum analyzer uses include
• Showing relative power levels across the band, to aid in selecting channels and
performing RF planning.
• Troubleshooting to finding the frequency, relative power level, and location of
interferers by rotating a single SM, or triangulating from multiple SMs in a
geographical area.
The OFDM spectrum analyzer, the FSK spectrum analyzer, and the FSK Receive Power Level
are all measuring and displaying peak power levels. The OFDM Receive Power Level is
measuring and displaying the average power level.
Due to this difference, the reported Receive Power Level on an OFDM SM can be 10 to 15 dB
lower than the value shown for that channel on the spectrum analyzer. For example, when
measuring power from an OFDM AP transmitting on a given channel the OFDM SM might show a
Receive Power Level of -70 dBm while the OFDM spectrum analyzer shows a power level of -54
for that channel.
In addition, an OFDM SM measures power across 10-MHz channels while an FSK SM measures
power across 20-MHz channels, so power measurements are not directly comparable between
the two.