User's Manual

PMP 450 Planning Guide
In the radio tab of the SM, you may set the following parameters.
Table 9 SM Radio attributes
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)
1-33