PMP 400/430 and PTP 200/230 Series
Motorola PMP Solutions User Guide Supplement
Issue 6.0 May 2011
Page 52 of 77
then invokes DFS (based on the region code and frequency band as shown in
Table 14
), the
Radio Frequency Carriers
and
External Antenna Gain
parameters will be displayed. Set them
as described below,
Save
Changes
, and
Reboot
again.
IMPORTANT!
Set the
Region
Code
,
Save
Changes
, and
Reboot
to see the context-
sensitive DFS parameters. Unlike with many context-sensitive
parameters, these do not appear in the GUI with only a
Save
Changes
.
Setting Radio Frequencies
APs and BHMs running DFS include an option for setting up to two alternate frequencies on the
“Configuration => Radio” page, in addition to the primary frequency. These alternate frequencies
are used in the unlikely event radar is detected and the main frequency is locked out due to DFS
detection.
If these are left at “None”, no backup frequencies will be used in the case of DFS
detection, and the AP or BHM will lock itself out from any transmission for 30 minutes.
If radar is detected on the main frequency, either at startup or during operation, a Channel
Availability Check will be performed on the 1
st
alternate frequency before it is then used for
transmission. If radar is detected on the 1
st
alternate frequency, either during Channel Availability
Check or during operation, a Channel Availability Check will be performed on the 2nd alternate
frequency before it is then used for transmission. If radar is detected on the 2nd alternate
frequency, either during Channel Availability Check or during operation, the radio will cease
transmission unless or until the primary channel clears its 30-minute lock-out.
The alternate frequencies configured in the AP/BHM must be included in the SM/BHS’s
Frequency Scan List, or the SMs/BHS can’t follow their AP/BHM if it switches to a new channel.
Additional frequencies may checked in the Frequency Scan List depending on local practices, for
example an operator may want to configure an SM to only register on certain frequencies to drive
a known SM to AP mapping. Another example would be an operator who configures an SM to
register on many frequencies so that it may find another AP to register to if its usual AP isn’t
available.
Note: use site surveys and RF planning to choose alternate frequencies useful for each sector,
and consider testing on the alternate frequencies
to ensure compatibility with the sector’s RF
environment.
4.5
EXTERNAL GAIN FIELD
An AP, SM, or BH needs to know the gain of its antenna to perform DFS and Auto-TPC
(Automatic Transmit Power Control) (SM only) consistent with regional or national regulations.
The GUI includes an
External Gain
field to support this.
Key points about the
External
Gain
field include:
External
Gain
is defined as the gain of the antenna minus the loss in the coaxial cable
and connectors.
The
External Gain
is set on the Configuration => Radio page of each module (AP, SM,
BHM, or BHS)
The default on a 5.4-GHz SM or a unit reset to factory defaults is
17
dB.
The default on a 5.8-GHz SM or a unit reset to factory default is
17
dB
The range is 0 to 35 dB.
