AS923-1 missing 1% DC

[martinichka]

Hi,

Currently we are certifying our LoRaWAN device (based on LBM 4.9.0) for use in Thailand. As far as we know Thailand uses the AS923-1 region config. To show compliance with our certification partner we now need to show that the device complies with a 1% duty cycle limitation. However, we see that LBM does not enable any duty cycle limitation for the AS923-1 region config. We checked the regional parameters (1.0.4), and this does specify that the duty cycle should be limited to 1% for this region, contrary to the LBM stack.

• Is our observation correct that LBM 4.9 does not implement the 1% for AS923?
• What is the reason the 1% DC as specified in the regional parameters is not implemented?

Best regards,
Marten

[aajn]

I have made a PR which implements the duty cycle (based on the EU868 implementation).

#165

[martinichka]

@lbm-team This issue is also reported via Semtech support, ticket number: 72742 (https://semtech.my.site.com/ldp/ldp_CaseDetail?Id=500RQ00000uiuPlYAI)

[lbm-team]

Hi Marten,

Yes, your observation is correct. LBM v4.9.0 does not enforce a duty-cycle limitation in AS923.

This behavior is intentional. AS923 is a LoRaWAN regional parameter set used across multiple countries with different regulatory requirements. Depending on the country, transmission management may rely on duty-cycle limitations, LBT, both, or neither. As a result, LBM does not apply a generic 1% duty-cycle restriction to all AS923 deployments. According to the feedback we received from the LoRa Alliance Regional Parameters Working Group, AS923 should not be interpreted as imposing a universal 1% duty-cycle requirement. Compliance with local regulations remains the responsibility of the device manufacturer and network operator.

We are currently evaluating how to improve flexibility in this area. The proposed Merge Request addresses the reported use case, but it is not a generic solution suitable for all AS923 deployments. We are therefore considering a more configurable approach for a future release.

Best regards,
LBM Team

[martinichka]

Hi @lbm-team,

Thank you for picking this up

Yes, I think making it configurable is a wise and useful strategy.

When doing that, please also make the "allowed frequencies" configurable. Currently we cannot limit the use frequencies in the stack without hacking into it, which we try to avoid for maintainability reasons.

The stack now uses these frequency ranges:

• AS923-1: 915–928 MHz
• AS923-2: 920–923 MHz
• AS923-3: 915–921 MHz
• AS923-4: 917–920 MHz

While countries have stricter limitations, e.g.:

• Thailand using AS923-1, but limited to 920–925 MHz
• Malaysia using AS923-1, but limited to 919–924 MHz
• Philippines using AS923-3, but limited to 915–918 MHz

It would be great if LBM would implement configuration next to the region (so on runtime) to following parameters:

• duty cycle: on/off
• actual frequency range: min/max

Let me know if you need an more input from our side. Do you want us to make a Pull Request for it for inspiration?

Best regards,
Marten