Installation Guide

Table Of Contents
Compliance with radio regulations PMP 450i and PTP 450i Configuration and User
Guide
Table 6 OFDM DFS operation based on Country Code setting
Country
Code
Band AP SM Weather Radar
Notch-Out
United
States
4.9-GHz No effect No effect No
5.8-GHz No effect No effect No
After an AP with DFS is powered on 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 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 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 does not begin transmission until it detects a beacon from an AP. If APs are not
transmitting, SMs will be silent.
Europe applies the ETSI specification to both APs and SMs, while Brazil applies it only to APs. In
the ETSI case, when an SM is powered on, it scans to find a Canopy beacon from a AP. If an AP is
found, the SM 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 proceeds through normal steps to
register to an AP.
If the SM does detect radar, it locks out that frequency for 30 minutes and continues
scanning other frequencies in its scan list.
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.
To simplify operation and ensure compliance, an SM takes on the DFS type of the AP to which it
registers. For example, when an SM in Europe registers to an AP with the Country Code set to
“United Kingdom”, that SM will use ETSI DFS, no matter what its Country Code is set to, even if
its Country Code is set to “None”. Note, the operator should still configure the Country Code in
the SM correctly, as future releases may use the Country 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
pmp-0957 (April 2015) 9