Gateway & nodes - too close? (traffic params included)

datnus · September 14, 2024, 8:31am

Can see “join” and uplink in Events

Can see Join Accept and request in LoRaWAN Frames

My AT+CFG for LSN50v2 is below
AT+TDC=60000 instead of default AT+TDC=1200000

LSN50 Device
Image Version: v1.8.1
LoRaWan Stack: DR-LWS-007
Frequency Band: EU868
DevEui= A8 40 41 54 11 83 2E 47

AT+DEUI=a8 40 41 54 11 83 2e 47
AT+APPEUI=a0 00 00 00 00 00 01 01
AT+APPKEY=
AT+DADDR=01 83 2e 47
AT+NWKSKEY=
AT+APPSKEY=
AT+ADR=1
AT+TXP=0
AT+DR=5
AT+DCS=0
AT+PNM=1
AT+RX2FQ=869525000
AT+RX2DR=0
AT+RX1DL=1000
AT+RX2DL=2000
AT+JN1DL=5000
AT+JN2DL=6000
AT+NJM=1
AT+NWKID=00 00 00 00
AT+FCU=0
AT+FCD=0
AT+CLASS=A
AT+NJS=0
AT+RECVB=0:
AT+RECV=0:
AT+RJTDC=20
AT+RPL=0
AT+VER=v1.8.1 EU868
AT+CFM=0,7,0
AT+CFS=0
AT+SNR=0
AT+RSSI=0
AT+TDC=60000
AT+PORT=2
AT+RX1WTO=24
AT+RX2WTO=6
AT+DECRYPT=0
AT+MOD=1
AT+INTMOD1=2
AT+INTMOD2=2
AT+INTMOD3=2
AT+WEIGAP=400.0
AT+5VT=500
AT+CHS=0
AT+DDETECT=1,1440,2880
AT+SETMAXNBTRANS=1,0
AT+DISFCNTCHECK=0
AT+DISMACANS=0

Device Profile for LSN50v2

Issue 1 - Join issue: So I would say your gateway does not receive Join Accept and forward to the LSN50v2.
=> You may upgrade ChirpStack to 4.8.1 or above.
=> And upgrade the firmware of your gateway.

Issue 2 - Bad signal: My signal is not so good for EU868.
It is fine for me as my LSN50v2 is tuned for AS923 (920-923Mhz).
The bad signal may be wrong attenna for LSN50v2 selling at your country.
=> Double check the label EU868 on the box of LSN50v2
=> Buy another antenna for LSN50v2 to fit EU868.

IoTThinks · September 15, 2024, 5:29am

@dom May I know where do you buy your Dragino devices? Via Amazon or Aliexpress or some where else?

Thanks a lot and have a nice day.

dom · September 16, 2024, 9:16am

@datnus Thank you so much for your time and efforts! I will study your data precisely and maybe find the solution. All of my devices are marked as EU868 so bad region shouldn’t be the cause.

May I ask you what was the approximate distance between your nodes and gateway?

dom · September 16, 2024, 9:25am

@IoTThinks Don’t remember the exact name now but it was a local distributor in Poland. Devices were not shipped from abroad. Nodes have 868 printed on the boxes and their boards, they also report this frequency band when connected to my computer. So I really hope that’s not fake

datnus · September 17, 2024, 3:12am

Within 1 meter only.
Later I flash back to AS923 and give you the RSSI/SNR.

I believe there are two issues in your case.

The node is not fake. However, you may try the node with other antenna.
Dragino LSN50v2 uses RP-SMA connector.
This is more important: Your gateway does not send back the Join Accept.
You may configure to use UDP Packet forwarder in your gateway.
And you may upgrade the firmware of your gateway.

IoTThinks · September 17, 2024, 3:13am

Thanks a lot for your response.

dom · September 17, 2024, 4:51pm

You’re absolutely welcome!

dom · September 19, 2024, 3:48pm

Thank you.

It may take some time to find it but I will try. I’ve noticed a visible difference of RSSI value with and without the antenna on node. Some samples:

Node with antenna off (unmounted): RSSI -103.00, SNR 6.50
Node with antenna on (mounted): RSSI -77.00, SNR 10.25

I have the latest 6.x firmware version but I’ve just noticed there is a major upgrade to 7.x. I will try to bump it up.

I think packet forwarding is configured in current server settings. It looks like this:

udp

By the way is there a way to investigate packet forwarding issue in any of Chirpstack logs or is it completely on gateway’s side?

datnus · September 20, 2024, 2:57am

I saw this. JoinAccept is downlink too.
You may want to try to upgrade the firmware of your Mikrotik gateway.
https://forum.mikrotik.com/viewtopic.php?t=201797

For debugging of missing Join Accept.
You may try to sub to these events.
https://www.chirpstack.io/docs/chirpstack-gateway-bridge/integrations/mqtt.html
OR
https://www.chirpstack.io/docs/chirpstack/integrations/mqtt.html

Please note the data may be encrypted but still can give you some hints.

OR
journalctl -u chirpstack -f -n 50
journalctl -u chirpstack-gateway-bridge -f -n 50

dom · September 20, 2024, 7:44am

That’s what I’m gonna do.

Thanks, I already know those. I created some piece of PHP code that subscribes gateway events and captures them. The only missing piece to go further is repeatable successful join So I will try to investigate there after successful firmware upgrade.