Join Request and Join Accept on different bands

Hi,

I am troubleshooting a node which has trouble connecting to my gateway. I can confirm that the gateway can uplink and downlink successfully as I have another LoRaWAN node which downlinking and uplinking and working well.

I am hoping that the image below reveals the issue. From what I can see on Chirpstack’ and this is backed up by the output of a tail -f /var/log/messages, it seems that the uplink is occurring on the AU915 band and the downlink or join accept is occurring on the freq: 923900000, which is outside band 2 on the AU915 band. Band 2 on AU915 is my current band of choice.

I believe that I have put the correct frequencies everywhere, so in chirpstack:

image

The code on my node:

lora.band = ‘AU915’
lora.set_config(ch_mask = ‘0,FF00’)
lora.set_config(ch_mask = ‘1,0000’)
lora.set_config(ch_mask = ‘2,0000’)
lora.set_config(ch_mask = ‘3,0000’)
lora.set_config(ch_mask = ‘4,0000’)

The beacon and channel config on my RPi Chirpstack gateway:

multi_sf_channels=[
916800000,
917000000,
917200000,
917400000,
917600000,
917800000,
918000000,
918200000,
]

Any suggestions on where I might look next?

Many thanks for your time.

Hi @roy_muzz,

How did you setup your Network Server .toml file?
There you are the regional parameters band.

https://www.chirpstack.io/network-server/install/config/

Thanks so much for the reply @pulidoj

The following is the contents of:

/home/ubuntu/chirpstack-docker/configuration/chirpstack-network-server/chirpstack-network-server.toml

[postgresql]
dsn=“postgres://chirpstack_ns:chirpstack_ns@postgresql/chirpstack_ns?sslmode=disable”

[redis]
url=“redis://redis:6379”

[network_server]
net_id=“000000”

[network_server.band]
name=“AU915”

[network_server.network_settings]
enabled_uplink_channels=[8, 9, 10, 11, 12, 13, 14, 15]

[network_server.gateway.backend.mqtt]
server=“tcp://mosquitto:1883”

[join_server.default]
server=“http://chirpstack-application-server:8003

[geolocation_server]
server=“chirpstack-geolocation-server:8005”
~

Hi @roy_muzz ,

I guess everything is working ok.
You defined properly the channels, but they are only uplink channels, not downlink.

If you have a look at LoRaWAN Regional Parameters document, in AU915 band downlinks channels frequencies go from 923.3 to 927.8, in 500 KHz bandwidth, just what you get in your downlink.

You should add extra channels to modify your Join Accept channels frequency.

  # Extra channel configuration.
  #
  # Use this for LoRaWAN regions where it is possible to extend the by default
  # available channels with additional channels (e.g. the EU band).
  # The first 5 channels will be configured as part of the OTAA join-response
  # (using the CFList field).
  # The other channels (or channel / data-rate changes) will be (re)configured
  # using the NewChannelReq mac-command.
  #
  # Example:
  # [[network_server.network_settings.extra_channels]]
  # frequency=867100000
  # min_dr=0
  # max_dr=5