MAC Settings

This section provides guidelines for configuring MAC settings for end devices from the CLI.

Command-line interface only

The instructions below use the command-line interface (CLI).

Learn how to install the CLI

MAC Settings and MAC State

MAC settings on The Things Stack are configurable per end device. To configure persistent MAC settings, make changes to mac-settings.desired_<parameter>. Updates to mac-settings.desired_<parameter> take effect on device creation, after OTAA join or ABP FCnt reset, ResetInd, or after MAC state reset.

mac-settings.<parameter> represents what the Network Server believes is configured on the end device, and should not be changed, unless the device does not conform to the LoRaWAN specification. It may however be necessary to set mac-settings.RX1_delay for ABP devices where this is not configured as part of activation.

mac-state can be used to test MAC settings in the current session. To update settings for testing in the current session, make changes to the mac-state.desired_parameters.<parameter>. Updates to the mac-state.desired_parameters.<parameter> are applied on the next uplink, and lost on reset.

The expected procedure for testing and updating settings is:

  1. Modify mac-state.desired_parameters.<parameter> to see changes in the current session
  2. Test that everything works as expected
  3. Modify mac-settings.desired_<parameter> to make the change permanent

See how this applies to the Rx1 delay parameter in the example below. If no settings are provided on device creation or unset, defaults are first taken from the device Frequency Plan if available, and finally from Network Server Configuration.

Example: Configure Rx1 Delay

Note:
The Things Stack configures the Rx1Delay to 5 seconds by default to accomodate for high latency backhauls and/or peering with Packet Broker, so this is the recommended configuration. For demonstration purposes, in this example we use 6 seconds.

To see Rx1 delay change in the current session, modify the mac-state.desired-parameters.rx1-delay parameter:

ttn-lw-cli end-devices update --application-id <application-id> --device-id <device-id> --mac-state.desired-parameters.rx1-delay RX_DELAY_6

The Network Server will schedule an RxTimingSetupReq MAC command to communicate a new Rx1Delay of 6 seconds to the device. The end device will answer with an RxTimingSetupAns MAC command in the next uplink. The Network Server will then start using the Rx1Delay of 6 seconds for scheduling downlinks. For this change to take effect, the end device does not need to perform a re-join.

To make the Rx1 delay change persistent upon end device re-join, modify the mac-settings.desired-rx1-delay parameter:

ttn-lw-cli end-devices update --application-id <application-id> --device-id <device-id> --mac-settings.desired-rx1-delay RX_DELAY_6

The Rx1 delay change will take effect only after the end device performs a re-join, i.e. in the new session. The Rx1Delay of 6 seconds will be communicated to the device during join procedure via Join-accept downlink message.

If the end device does not conform to the LoRaWAN Specification and has a custom Rx1 delay configured in it (6 seconds in this example), modify the mac-settings.rx1-delay parameter:

ttn-lw-cli end-devices update --application-id <application-id> --device-id <device-id> --mac-settings.rx1-delay RX_DELAY_6

The Network Server will start using the Rx1Delay of 6 seconds for downlink communication with the end device.

Available MAC Settings

Run the following command to get a list of all available MAC settings and available parameter values:

ttn-lw-cli end-devices set --help

You can also refer to the End Device API Reference page for documentation on the available MAC settings and MAC state parameters.

Class Specific Settings

Settings that are useful based on device class are:

All devices:

  • mac-settings.factory-preset-frequencies

Class A:

  • mac-settings.desired-rx1-delay
  • mac-settings.desired-rx1-data-rate-offset
  • mac-settings.desired-rx2-data-rate-index
  • mac-settings.desired-rx2-frequency
  • mac-settings.supports-32-bit-f-cnt
  • mac-settings.use-adr

Class A ABP:

  • mac-settings.resets-f-cnt

Class B:

  • mac-settings.class-b-timeout
  • mac-settings.ping-slot-periodicity
  • mac-settings.desired-ping-slot-data-rate-index
  • mac-settings.desired-ping-slot-frequency

Class C:

  • mac-settings.class-c-timeout

Some additional examples are included below. All settings are available at the End Device API Reference page and can be viewed using the ttn-lw-cli end-devices set --help command.

Examples

Configure Factory Preset Frequencies for ABP Devices

To tell The Things Stack which frequencies are configured in an ABP device, set the mac-settings.factory-preset-frequencies parameter. For example, to configure a device using the default EU868 frequencies, use the following command:

ttn-lw-cli devices update <app-id> <device-id> --mac-settings.factory-preset-frequencies 868100000,868300000,868500000,867100000,867300000,867500000,867700000,867900000
Note:
For ABP devices, mac-settings.factory-preset-frequencies should be specified on device create or the settings will only take effect after MAC reset.

Set Duty Cycle

To change the duty cycle, set the desired-max-duty-cycle parameter. For example, to set the duty cycle to 0.098%, use the following command:

ttn-lw-cli end-devices set <app-id> <device-id> --mac-settings.desired-max-duty-cycle DUTY_CYCLE_1024

See the End Device API Reference for available fields and definitions of constants. DUTY_CYCLE_1024 represents 1/1024 ≈ 0.098%.

Enable ADR

To enable ADR, set the mac-settings.use-adr parameter:

ttn-lw-cli end-devices set <app-id> <device-id> --mac-settings.use-adr=true

See the Adaptive Data Rate section for detailed information on configuring ADR parameters and ADR margin using MAC settings.

Set RX1 Delay

The RX1 delay of end devices is set to 5 second by default. To change it, set the desired-rx1-delay parameter:

ttn-lw-cli end-devices set <app-id> <device-id> --mac-settings.desired-rx1-delay RX_DELAY_5

Unset MAC settings

The CLI can also be used to unset MAC settings (so that the default ones are used):

ttn-lw-cli end-devices set <app-id> <device-id> --unset mac-settings.rx1-delay

Session and MAC State Reset

Resetting session and MAC state for OTAA devices will wipe out all session and MAC data, and the end device will need to perform a rejoin on The Things Stack network. For ABP devices, only MAC state gets reset, while session keys, DevAddr and downlink queue are preserved.

Session and MAC state can be reset through the Console - navigate to your end device’s General settings tab, scroll down to the Network layer section, press the Reset session and MAC state button and confirm.

To reset session and MAC state using the CLI:

ttn-lw-cli end-devices reset --application-id <application-id> --device-id <device-id>
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