User guide

Canopy System User Guide Diagramming Network Layouts
pmp-0229 (Mar 2013)
155
CAUTION!
Regardless of whether 2.4-, 5.2-, 5.4-, or 5.7-GHz modules are deployed,
channel separation between modules should be at least 20 MHz for 1X
operation or 25 MHz for 2X.
Physical Proximity
A BH and an AP on the same tower require a CMM. The CMM properly synchronizes the
transmit start times of all modules to prevent interference and desensing of the modules. At closer
distances without sync from a CMM, the frame structures cause self interference.
Furthermore, a BH and an AP on the same tower require that the effects of their differing receive
start times be mitigated by either
• 100 vertical feet (30 meters) or more and as much spectral separation as possible within the
same frequency band range.
• the use of the frame calculator to tune the Downlink Data % parameter in each, so that the
receive start time in each is the same. See Using the Frame Calculator Tool (All) on Page 542.
Spectrum Analysis
You can use an SM or BHS as a spectrum analyzer. See Mapping RF Neighbor Frequencies on
Page 125. Through a toggle of the Device Type parameter, you can temporarily transform an AP
into an SM to use it as a spectrum analyzer.
Power Reduction to Mitigate Interference
Where any module (SM, AP, BH timing master, or BH timing slave) is close enough to another
module that self-interference is possible, you can set the SM to operate at less than full power. To
do so, perform the following steps.
CAUTION!
Too low a setting of the Transmitter Output Power parameter can cause a link
to a distant module to drop. A link that drops for this reason requires Ethernet
access to the GUI to re-establish the link.
Procedure 3: Reducing transmitter output power
1. Access the Radio tab of the module.
2. In the Transmitter Output Power parameter, reduce the setting.
3. Click Save Changes.
4. Click Reboot.
5. Access the Session Status tab in the Home web page of the SM.