Losing Frames after changing region configuration

Question

Hi,

We created a new Chirpstack Gateway Bridge Service to implement a new region configuration that limits the data rate of the installation. However, after creating the service and migrating the packet forwarder port of the gateways, we are losing frames in the device log.

We can see that the gateway is receiving the frames, but the device is missing them.

Most of the devices are sending in DR5, but the new region configuration has a maximum DR3.

I'm getting an error message when uploading photos to this post.

Ultimately, we only want to limit the DR of the devices because, at DR5, we are missing some frames due to the coverage limit. However, due to the high frequency between the frames, they cannot go lower than DR4 or DR3. That's why we created the new region configuration to force them to get the LinkADRreq command.

What could be the issue, and is our approach correct?

Best regards,

Orne Brocaar · Answer

Ultimately, we only want to limit the DR of the devices because, at DR5, we are missing some frames due to the coverage limit.

I think there could be an other option if link-margin is the issue.

You could set the installation_margin value to a higher value than 10, this will make the ADR algorithm more conservative, as margin = uplink SNR - min. required SNR - installation margin. The ADR algorithm uses the margin to calculate if the DR can be increased.

Please note that ChirpStack does not enforce a minimum ADR. At least the default ADR algorithm doesn't. You could implement a custom one in JS if you want.

Losing Frames after changing region configuration

1 Answers