Applicable Versions: 5.12.0
Applicable Platforms: ePMP46XX
Firmware version 5.12.0 introduces the AFC Antenna Height Mode feature for ePMP46XX series.
Automated Frequency Coordination (AFC) is a set of techniques used to enable safe channel sharing in the 6 GHz band between outdoor Wi-Fi 6E devices and existing incumbent users. As defined by the FCC, any newly installed Access Point (AP) operating in the 6 GHz band must query a certified AFC database to ensure that its operation will not interfere with registered incumbent users in that area on a given channel.
Prior to this enhancement, AFC calculations relied solely on GPS-provided location and altitude information. The device reported its position and elevation to the AFC service provider, which then requested operating parameters from the AFC database.
Starting with firmware version 5.12.0, users can choose how antenna height information is provided to AFC by selecting one of two antenna height modes:
- Auto (AMSL)
- Manual (AGL)
Auto (AMSL)
In Auto mode, the device uses altitude information obtained from the integrated GPS receiver.
The reported antenna height is based on Above Mean Sea Level (AMSL) measurements, which is the same behavior used in previous firmware releases.
Note: Starting with firmware version 5.12.0, Auto (AMSL) is the default antenna height mode. Existing AFC deployments can therefore be upgraded without requiring any additional antenna height configuration.
This mode is recommended when reliable GPS information is available and no site-specific antenna height data is required.
Manual (AGL)
In Manual mode, the professional installer manually specifies the antenna height Above Ground Level (AGL).
This allows the AFC request to use the actual antenna installation height rather than relying solely on GPS-derived elevation data.
Manual mode can be particularly useful in situations where:
- GPS altitude measurements are inaccurate or inconsistent.
- The antenna is installed on towers, rooftops, water tanks, or other elevated structures.
- The installer has precise knowledge of the antenna’s height above the surrounding terrain.
- More accurate AFC calculations are desired based on the real installation environment.
Providing a more accurate antenna height may help the AFC system better evaluate the operating environment and determine appropriate power limits for the installation.
If the antenna height above ground is not known, users may switch the Antenna Height Mode to Auto (AMSL) and allow the device to use GPS-derived altitude information instead.
On GUI navigate to Configuration > Radio
On the Configuration > Radio page, users can configure:
- Antenna Height Mode
- Antenna Height Unit (Feet or Meters)
- Antenna Height Value
- Antenna Height Accuracy
The Antenna Height Accuracy parameter defines the uncertainty of the entered AGL value and indicates how precisely the antenna’s vertical position is known relative to the surrounding terrain.
Important Note
When using Manual (AGL) mode, Cambium Networks recommends configuring the antenna height and accuracy values based on verified site survey information.
If the exact antenna height or accuracy is unknown, consult a qualified installer or RF specialist to ensure that the AFC request contains accurate deployment information.
cnMaestro Notification for AFC EIRP Changes
Firmware version 5.12.0 introduces a new cnMaestro notification for AFC EIRP changes.
A notification is generated whenever the newly granted AFC EIRP value is lower than the previously assigned value.
Example:
- Previous EIRP: 36 dBm
- New EIRP: 25 dBm
This notification helps administrators quickly identify AFC-related power reductions that may affect link performance.
MIB objects
cambiumAfcAntennaHeightType OBJECT-TYPE
SYNTAX Integer32 (1|2)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Antenna height calculation type.
1 - AMSL (above mean sea level) is used from GPS receiver.
2 - AGL (above ground level) configured by professional installer in cambiumAfcAntennaHeightAglValue.
Device Allocation: AP, SM"
DEFVAL { 2 }
::= { cambiumAFCStatus 27 }
cambiumAfcAntennaHeightAglUnits OBJECT-TYPE
SYNTAX Integer32 (1|2)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Units for antenna height above ground level:
1 - feets
2 - meters
Device Allocation: AP, SM"
DEFVAL { 1 }
::= { cambiumAFCStatus 28 }
cambiumAfcAntennaHeightAglValue OBJECT-TYPE
SYNTAX Integer32 (0..1000)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Antenna height above ground level.
Device Allocation: AP, SM"
DEFVAL { 0 }
::= { cambiumAFCStatus 29 }
cambiumAfcAntennaHeightAglAccuracy OBJECT-TYPE
SYNTAX Integer32 (1..1000)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Antenna height above ground level measured accuracy.
Device Allocation: AP, SM"
DEFVAL { 1 }
::= { cambiumAFCStatus 30 }
cnMaestro Template
{
"device_props": {
"cambiumAfcAntennaHeightType": "2",
"cambiumAfcAntennaHeightAglUnits": "1",
"cambiumAfcAntennaHeightAglValue": "2",
"cambiumAfcAntennaHeightAglLimitMeters": "100",
"cambiumAfcAntennaHeightAglAccuracy": "1"
}
}