PMP 400 and PTP 200 Series
Canopy User Guide Supplement
Issue 3, January 2009
Page 26 of 45
It takes two reboots to set the parameters described below on a module starting from factory
defaults. Set the Region Code as described above, “Save Changes”, and “Reboot”. If the module
then invokes DFS (based on the Region Code and frequency band as shown in Table 6), 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 or BHM must be included in the SM’s or BHS’s
Frequency Scan List, or the SMs/BHSs 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 if an operator wants to configure an SM to only register on certain frequencies to drive a
known SM to AP mapping, or configure 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
NET ANTENNA 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 a
Net Antenna Gain
field to support this.
Key points about the
Net
Antenna
Gain
field include:
•
Net
Antenna
Gain
is defined as the gain of the antenna minus the loss in the coaxial
cable and connectors.
•
The
Net Antenna Gain
is set on the Configuration -> Radio page of each module
(AP, SM, BHM, or BHS)
•
The default on a new unit, or when the unit is reset to factory defaults, is
17
dB for
5.4 GHz radios and
16
dB for 4. 9 GHz radios..
•
The range is 0 to 35 dB.
