User guide

Analyzing the RF Environment Engineering Your RF Communications
128
pmp-0229 (Mar 2013)
The master radios properly implement the regionally-imposed DFS conditions after reading the
value of the Region Code parameter, which Release 8.2 introduced. The effect of the DFS feature,
based on the Region Code value (if this parameter is present), is shown in Table 29.
Table 29: Effect of DFS feature
Region
Code
1
Value
Effect of DFS Feature
900
MHz
2.4
GHz
5.2
GHz
5.4
GHz
5.7
GHz
AP
SM
AP
SM
BH
AP
BHM
SM
BHS
AP
BHM
SM
BHS
AP
BHM
SM
BHS
Australia
No
effect
No
effect
FCC/IC DFS
with notch
2
No
effect
No effect
No
effect
Brazil
ETSI DFS
ETSI
DFS
No effect
No
effect
Canada
No
effect
No
effect
FCC/IC
DFS
3
No effect
FCC/IC DFS
with notch
2
No
effect
No effect
No
effect
Europe
No
effect
ETSI DFS
ETSI
DFS
ETSI DFS
ETSI
DFS
Russia
No effect No effect No effect
No
effect
United
States
No
effect
No
effect
FCC/IC
DFS
3
No effect FCC/IC DFS
No
effect
No effect
No
effect
Other
No effect on radio operation
None
AP or BHM will not transmit
NOTES:
1. In all cases, set the Region Code parameter to the appropriate region. Then the software will
determine the correct use of DFS.
2. Center channel frequencies from 5580 to 5670 MHz, inclusive, are omitted (notched out of the
otherwise continuous band) from the GUIs and these radios cannot operate in that range.
3. Newly manufactured P10 5.2-GHz radios use DFS. Radios that were purchased without DFS
are not required to use DFS.
When an AP or BHM boots, it performs a channel availability check (CAC) for one minute on its main
carrier frequency, without transmitting, as it monitors the channel for radar. If it detects no radar signature
during this minute, the radio then proceeds to normal beacon transmit mode. If it does detect a radar
signature, it locks that frequency carrier out for 30 minutes, and switches to the Alternate Frequency
Carrier 1, which is set in the Configuration => Radio web page.
For the next minute, the radio monitors this new frequency for radar and, if it detects no radar, it proceeds
to beacon transmit mode. If it does detect radar, it locks that frequency carrier out for 30 minutes, and
switches to Alternate Frequency Carrier 2. For the minute that follows, the radio monitors this second
alternate frequency and responds as described above to the presence or absence of radar on its current
channel, switching if necessary to the next channel in line.
The ETSI EN 301 893 v1.3.1 specification requires DFS on a slave radio (SM or BHS) also. A slave radio
transmits only if it receives a beacon from the master radio (AP or BHM). When the slave radio with DFS
boots, it scans to distinguish whether a master radio beacon is present. If it finds a master, the slave