Configuring different RX1 delay for different devices

ChirpStack Network Server
1

Dear community,
Is it possible to set different RX1 delays for different devices in chirpstack.

Thank you

1 Like
2

Hi Shubham,

Yes it is possible. however you have to create separate profile for devices on chirpstack.

I hope this would help you!

Thank you.

3

The above is partly true. The device-profile contains the initial boot parameters and as part of this, you can set the rx delay in case of ABP. However, ChirpStack will send a mac-command to the device to set the rx delay as configured in the toml file.

In my opinion the rx delay is not a value that should be set on a per-device basis, but is dependent on your infrastructure. The rx delay makes sure that the roundrip time GW -> NS -> processing -> GW is within the receive windows. Especially in case of cellular or satellite back-hauls you want to tweak this value.

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4

@brocaar

Thanks again for your constant effort - looking forward to V4!

I have seen a few posts requesting this feature and I understand your point of view, where the RX1 delay should be set for the infrastructure. Nonetheless when integrating different types of devices with different firmware capabilities there are some issues : some are not able to process mac commands for example and that means part of the fleet drops offline when changing this setting.

I wanted to mention the Things Stack
They seem to allow a different RX1 delay for each device. I thought this might be worth a look - for your reconsideration.

Currently our strategy might involve the use of the packet multiplexer and then registering devices that are able to take a different RX1 delay on a new CS. We don’t know what other workaround could work…any idea is welcome!

5

If these devices are not able to process mac-commands correctly, then these would never pass the LoRaWAN certification. But this should not be an issue, because if the device does not respond to the rx1 delay change, it will not break these devices. ChirpStack keeps a snapshot of the settings for each device, as as long as the rx1 delay change has not been confirmed by the device, the old value will be used :slight_smile: