Join successful but no UnconfirmedDataUp frames – Mixed US915 and AS923 gateways (XYZ property)

Ranjith 11
Viewed 36

Hi Team,

We are facing an issue at our XYZ property (US915 region) where devices are successfully sending Join Requests, and Join Accept is being processed correctly in ChirpStack. However, after activation, we are not seeing any UnconfirmedDataUp or UnconfirmedDataDown frames from the sensors.

Setup Details:

  1. Property has gateways supporting US915 and AS923 frequency bands.

  2. Necessary region configurations were updated on the gateway side accordingly.

  3. In ChirpStack, we are able to see Join Request and Join Accept.

  4. No application payload data is received after join.

  5. Devices were reset and re-tested, but behavior remains the same.

  6. All the US915 supporting gateways and its corresponding sensors work fine.

Additional Context:

We have other properties where AU915 and US915 gateways coexist, and with proper configuration, data is received successfully from sensors without any issue.

For this XYZ property:

  1. We applied similar settings, replacing AU915 with AS923 where required.

  2. Join procedure works fine.

  3. No uplink data after activation.

Questions:

  1. Could the coexistence of US915 and AS923 gateways in the same property cause any uplink routing or channel-mask related issue?

  2. Are there any specific ChirpStack regional or channel-mask configurations required when mixing US915 and AS923 gateways?

  3. Since join works but no data follows, could this indicate a downlink channel-mask or RX window issue?

If any additional logs or configuration details are required, please let me know.

Any guidance would be appreciated.

troubleshooting configuration devices gateways chirpstack
1 Answers

Property has gateways supporting US915 and AS923 frequency bands.

Please make sure that the MQTT topic prefix is configured for the correct region. A gateway is either a US915 or a AS923 gateway in ChirpStack. This way, ChirpStack knows which region configuration to attach to the received uplink.

It is perfectly fine to have multiple gateways using multiple topic prefixes to mix multiple regions.

You might also want to check the server logs to see if there are more errors.

Orne Brocaar811

If the gateways are properly configured & forwarding to the correct MQTT topics, then the above is all the feedback that I can provide, without access to the environment and devices. You need to find out why the devices stay in the rejoin loop. It could be that they are not receiving the join-accepts?

Orne Brocaar•

hey @brocaar , thanks for the reply. We actually set the topic prefix correctly. We set XYZ_as923 for AS923 region gateways and XYZ_us915 for US915 region gateways. All AS923 region supports 923.2 MHz to 923.4 MHz. But still we are facing the same problem of not getting any data from the sensors. We are able to see continuous Join Request and Join Accept under Lorawan Frames.

And when you say server logs, what logs are you mentioning ?
we normally run this -
docker logs -f --tail 10 chirpstack-docker_chirpstack_1
while checking if gateways/sensors message is received.

Ranjith•
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