User Guide

PMP 450 Planning Guide
Attribute Meaning
Custom Radio Frequency
Scan Selection List
Check any frequency that you want the SM to scan for AP transmissions.
Prior to System Release 13.1, the PMP 450 SM boot sequence included loading
the current channel bandwidth (10 MHz or 20 MHz, but not both) and
frequency band configuration (3.6 GHz) and scanning selected frequencies in
the respective frequency band. After a scan of all the selected frequencies the
SM would attempt to register to the best AP based on the SM’s current
configuration.
With the introduction of the Full Spectrum Band Scan feature in 12.0.3, SMs
first boot into the smallest selected channel bandwidth (10 MHz, if selected)
and scan all selected frequencies across the 3.6GHz frequency bands.
After this scan, if a wider channel bandwidth is selected (20 MHz), the SM
automatically changes to 20 MHz channel bandwidth and then scans for APs.
After the SM finishes this final scan it will evaluate the best AP with which to
register. If required for registration, the SM changes its channel bandwidth
back to 10 MHz to match the best AP.
The SM will attempt to connect to an AP based on power level (which affects
the modulation state), channel bandwidth (which affects throughput) and
number of SM registrations to the AP (which affects system contention
performance).
If it is desired to prioritize a certain AP over other available APs, operators
may use the Color Code Priority feature on the SM. Utilization of the Color
Code feature on the AP is recommended to further constrain the SM’s AP
selection.
If the SM does not find any suitable APs for registration after scanning all
channel bandwidths, the SM restarts the scanning process beginning with the
smallest configured channel bandwidth.
By default, beginning with System Release 12.0.3 SMs are configured to scan
all available frequencies and all available channel bandwidths. This allows
operators to install SMs and allow them to register with no pre-configuration
or staging required. SMs upgraded from a previous release to 12.0.3 retain
frequency and channel bandwidth configuration.
Selecting multiple frequencies and multiple channel bandwidths impacts the
SM scanning time. The biggest consumption of time is in the changing of the
SM channel bandwidth setting. The worst case scanning time is approximately
two minutes after bootup (SM with all frequencies and channel bandwidths
selected and registering to an AP at 10 MHz). If only one channel bandwidth
is selected the time to scan all the available frequencies and register to an AP
is approximately one minute after bootup.
Other scanning features such as Color Code, Installation Color Code, and
RADIUS authentication are unaffected by the Full Band Scan feature.
pmp-0047 (March 2014)
1-35