[RAK7268C] Missing ACK/Join Responses

LPWAN Industrial Gateways / Concentrators
1

Hi,

I have LoRaWAN network based on RAK7268C and AWS IoT Core LoRaWAN server. Gateway is connected by Ethernet cable. For some time I’m struggling with 2 problems:

  • sometimes I don’t receive ACK response frame for Downlink Confirmed message. My device is resending that message with 2 minute interval, but sometimes I receive ACK response after at least 3-4 tries. I checked LoRa Packet logger to be sure that ACK frame wasn’t transmited.
  • sometimes I don’t receive Join Response after Join Request message. Usually I have to send at least 2 Join Requests and after second message I got Join Response. Worst case I’ve seen was when device was trying to connect for over 4 hours. In this scenario I was also checking LoRa Packet logger in Gateway’s administration panel.

I’ve checked system’s log and there is something strenge. Every time ACK response is missing there are 2 warnings marked on screen:
Thu Oct 19 10:30:54 2023 user.warn basicstation[32190]: [S2E:WARN] Unknown field in dnmsg - ignored: regionid
Thu Oct 19 10:30:54 2023 user.warn basicstation[32190]: [S2E:WARN] ::0 diid=13472 [ant#0] - unable to place frame

2023_10_19_13_42_22_RAK7268C_Log_systemowy_LuCI_Vivaldi
2023_10_19_13_42_22_RAK7268C_Log_systemowy_LuCI_Vivaldi1882×946 61.3 KB

2023_10_19_13_42_22_RAK7268C_Log_systemowy_LuCI_Vivaldi2
2023_10_19_13_42_22_RAK7268C_Log_systemowy_LuCI_Vivaldi21889×979 125 KB

Any ideas if these warning are related with my problem?

2

Hi @meloon it might be a connectivity issue. Can you share the firmware version, what type of internet connection you are using, and if possible logs in debug level - maybe on PM.

3

Firmware is the newest: 1.3.9_RAK b186
Gateway is connected by Ethernet to switch, I have very stable fiber internet connection.

4

So i found something in logs related with missing frames:

Fri Oct 20 13:13:45 2023 user.warn basicstation[30835]: [S2E:WARN] Unknown field in dnmsg - ignored: regionid
Fri Oct 20 13:13:45 2023 user.debug basicstation[30835]: [S2E:VERB] ::0 diid=3711 [ant#0] 868.5MHz - no DC in band: txtime=11:13:50.506 free=11:14:26.831
Fri Oct 20 13:13:45 2023 user.debug basicstation[30835]: [S2E:VERB] ::0 diid=3711 [ant#0] - class A has no more alternate TX time
Fri Oct 20 13:13:45 2023 user.warn basicstation[30835]: [S2E:WARN] ::0 diid=3711 [ant#0] - unable to place frame

This error appears every time when downlink frame is missing.
I found something on TTN wiki:
https://www.thethingsindustries.com/docs/gateways/troubleshooting/#im-seeing-no-dc-in-band-error-in-the-lora-basics-station-gateways-packet-forwarder-logs-what-is-causing-this
but it make’s no sens to me. My gateway is handling only one device, all 8 channels are free to use.

5

Hi @meloon
Did you ever manage to get to the bottom of this? I am also struggling with the same issue. Trying to OTAA a bunch of devices and they sometimes join, sometimes don’t. On AWS I get the join request and see that a join accept has been sent, but the gateway is not transmitting it to the node.
Not having this issue with the RAK7289C though… Very annoying, but hope it’s something simple.

It feels like there is a time-out on this gateway firmware for joins? Like a duty cycle limit.

6

Exactly the same happening to me with a RAK7268C and a RAK4631R board on AWS IoT Core. Join request & Join accept are visible on AWS through the Network Analyzer but Basic Station reports “unable to place frame” and the join accept doesn’t reach the device (not always, but >50% of cases).

Works perfectly with Loriot both with packer forwarder & basic station.

I was wondering too if it’s a duty cycle limitation, been trying various options on AWS device profiles but no luck yet.