PMP 400/430 and PTP 200/230 Series Configuration and User Guide
pmp-0042 (March 2014)
Page 59 of 98
After an AP or BHM with DFS boots it performs a channel availability check on its main carrier frequency for
1 minute, monitoring for the radar signature without transmitting. If no radar signature is detected during this
minute, the module then proceeds to normal beacon transmit mode. If it does detect a radar signature, the
frequency is marked for a 30 minute non-occupancy period, and the module moves to its 1
st
alternate carrier
frequency. The AP/BHM continues this behavior through its 2nd alternate frequency if needed and then
waits until the first frequency ends the 30 minute non-occupancy period. While operating, if the AP/BHM
detects a weather radar signature it marks the current carrier frequency for a 30 minute non-occupancy
period and moves to check the next-in-line carrier frequency.
An SM/BHS does not begin transmission until it detects a beacon from an AP/BHM. If APs/BHMs are not
transmitting, SMs/BHSs will be silent.
The FCC and IC require DFS only on APs/BHMs. Europe applies the ETSI specification to both APs/BHMs
and SMs/BHSs, while Brazil applies it only to AP/BHMs. In the ETSI case, when an SM/BHS boots, it scans
to find a Canopy beacon from a AP/BHM. If an AP/BHM is found, the SM/BHS performs a channel
availability check on that frequency for 1 minute, monitoring for the radar signature, without transmitting. A
DFS decision is made based on the following:
If no radar pulse is detected during this 1 minute, the SM/BHS proceeds through normal steps to
register to an AP/BHM.
If the SM/BHS does detect radar, it locks out that frequency for 30 minutes and continues scanning
other frequencies in its scan list.
Note, after an SM with DFS has seen a radar signature on a frequency and locked out that frequency, it may
connect to a different AP if color codes, AP transmitting frequencies, and SM scanned frequencies support
that connection.
BHSs would not be expected to connect to a different BHM, as backhaul links should be configured using
color codes and authentication to ensure a BHS only connects with its intended BHM.
To simplify operation and ensure compliance, an SM/BHS takes on the DFS type of the AP/BHM to which it
registers. For example, when an SM in Europe registers to an AP with the Region Code set to “Europe”, that
SM will use ETSI DFS, no matter what its Region Code is set to, even if its Region Code is set to “None”.
Note, the operator should still configure the Region Code in the SM correctly, as future releases may use the
Region Code for additional region-specific options.
For all modules running DFS, the module displays its DFS state on its
Home => General Status
page as
one of the following:
Checking Channel Availability Remaining time
n
seconds
,
where
n counts down from 60 to 1.
Normal Transmit
Radar Detected Stop Transmitting for
n
minutes
,
where n counts
down from 30 to 1.
Idle
, only for SM/BHS, indicates module is scanning, but has not detected a beacon
from an AP/BHM. Once it detects beacon, the SM/BHS begins a Channel Availability
Check on that frequency.
Regulatory Note: A PMP 430 Series AP with a Region Code set to United States will not be configurable to
another Region Code by installers or end users. This is in response to FCC KDB 594280 and ensures that
end users and professional installers will not have access to settings which could allow a radio to be
configured to operate in a manner other than that which was specified in the FCC equipment authorization
grant.
Within the United States and its territories the PMP 430 region code is pre-configured to United States and
not selectable in the Configuration => General web page. Radios sold in regions outside of the United States
and its territories are required to set the Region Code to the region in which it is used.
