LMIC Library Always Does Unwanted Downlink

End Devices (Nodes) LMIC
21

I have the issue of uplinks downlinks with no payload since integrating TTN with AWS. It seems that the node is not ack whatever AWS IoT or TTN is sending on the port 0 uplinks.

If it was only ADR there would be only one uplink downlink and the node would respond changing the rate, but in this case the uplinks continue.

The interesting thing is that uplink downlink from TTN console also stops working. When I delete the Stack of the integration on AWS Elastic BS, this issue goes away and also the port 0 uplinks cease.

Can somebody advise how to debug what AWS IoT of the Stack is sending to get this behaviour?

22

Are you perhaps mixing up the terms uplink and downlink? Node transmissions are uplinks.

23

Yes, cslorabox, sorry about that, Downlinks keep being generated with empty payload on port 0. I have run the decoder but there are no ADR acks requests. As soon as I delete the EB Stack , they are gone.

24

Look for MAC commands in the fopts field

25

Got the following:

FOpts = 0340020071033500FF01

Message Type = Unconfirmed Data Down
Direction = down
FCnt = 0
FCtrl.ACK = false
FCtrl.ADR = true

I’ve tested this with US915 and AUS915, strange thing is that it only appears when enabling the integration (Elastic Bean template on AWS)