Channel Monitoring#
This module includes functions for channel monitoring feature.
The functions in this module are available when channel monitor feature (OPENTHREAD_CONFIG_CHANNEL_MONITOR_ENABLE
) is enabled.
Channel monitoring will periodically monitor all channels to help determine the cleaner channels (channels with less interference).
When channel monitoring is active, a zero-duration Energy Scan is performed, collecting a single RSSI sample on every channel per sample interval. The RSSI samples are compared with a pre-specified RSSI threshold. As an indicator of channel quality, the channel monitoring module maintains and provides the average rate/percentage of RSSI samples that are above the threshold within (approximately) a specified sample window (referred to as channel occupancy).
Functions#
Enables or disables the Channel Monitoring operation.
Indicates whether the Channel Monitoring operation is enabled and running.
Get channel monitoring sample interval in milliseconds.
Get channel monitoring RSSI threshold in dBm.
Get channel monitoring averaging sample window length (number of samples).
Get channel monitoring total number of RSSI samples (per channel).
Gets the current channel occupancy for a given channel.
Function Documentation#
otChannelMonitorSetEnabled#
otError otChannelMonitorSetEnabled (otInstance * aInstance, bool aEnabled)
Enables or disables the Channel Monitoring operation.
[in] | aInstance | A pointer to an OpenThread instance. |
[in] | aEnabled | TRUE to enable/start Channel Monitoring operation, FALSE to disable/stop it. |
Once operation starts, any previously collected data is cleared. However, after operation is disabled, the previous collected data is still valid and can be read.
Note
OpenThread core internally enables or disables the Channel Monitoring operation when the IPv6 interface is brought up or down, for example in a call to
otIp6SetEnabled()
.
82
of file include/openthread/channel_monitor.h
otChannelMonitorIsEnabled#
bool otChannelMonitorIsEnabled (otInstance * aInstance)
Indicates whether the Channel Monitoring operation is enabled and running.
[in] | aInstance | A pointer to an OpenThread instance. |
Returns
TRUE if the Channel Monitoring operation is enabled, FALSE otherwise.
92
of file include/openthread/channel_monitor.h
otChannelMonitorGetSampleInterval#
uint32_t otChannelMonitorGetSampleInterval (otInstance * aInstance)
Get channel monitoring sample interval in milliseconds.
[in] | aInstance | A pointer to an OpenThread instance. |
Returns
The channel monitor sample interval in milliseconds.
102
of file include/openthread/channel_monitor.h
otChannelMonitorGetRssiThreshold#
int8_t otChannelMonitorGetRssiThreshold (otInstance * aInstance)
Get channel monitoring RSSI threshold in dBm.
[in] | aInstance | A pointer to an OpenThread instance. |
Returns
The RSSI threshold in dBm.
112
of file include/openthread/channel_monitor.h
otChannelMonitorGetSampleWindow#
uint32_t otChannelMonitorGetSampleWindow (otInstance * aInstance)
Get channel monitoring averaging sample window length (number of samples).
[in] | aInstance | A pointer to an OpenThread instance. |
Returns
The averaging sample window.
122
of file include/openthread/channel_monitor.h
otChannelMonitorGetSampleCount#
uint32_t otChannelMonitorGetSampleCount (otInstance * aInstance)
Get channel monitoring total number of RSSI samples (per channel).
[in] | aInstance | A pointer to an OpenThread instance. |
The count indicates total number samples per channel by channel monitoring module since its start (since Thread network interface was enabled).
Returns
Total number of RSSI samples (per channel) taken so far.
135
of file include/openthread/channel_monitor.h
otChannelMonitorGetChannelOccupancy#
uint16_t otChannelMonitorGetChannelOccupancy (otInstance * aInstance, uint8_t aChannel)
Gets the current channel occupancy for a given channel.
[in] | aInstance | A pointer to an OpenThread instance. |
[in] | aChannel | The channel for which to get the link occupancy. |
The channel occupancy value represents the average rate/percentage of RSSI samples that were above RSSI threshold ("bad" RSSI samples).
For the first "sample window" samples, the average is maintained as the actual percentage (i.e., ratio of number of "bad" samples by total number of samples). After "window" samples, the averager uses an exponentially weighted moving average. Practically, this means the average is representative of up to 3 * window
last samples with highest weight given to the latest kSampleWindow
samples.
Max value of 0xffff
indicates all RSSI samples were above RSSI threshold (i.e. 100% of samples were "bad").
Returns
The current channel occupancy for the given channel.
156
of file include/openthread/channel_monitor.h