Single-channel gateway: get rx1 frequency for uplink frequency error: lorawan/band: unknown channel for frequency: 902299987


#1

I’m implementing the loraserver with a single changel gateway and an esp32 based lora-node. Looking at the loraserver log, I’m getting the following error:

My question is: where it set up this frequency 902299987? I’ve checked and both esp32 node and the gateway were set up with the frequency 902300000.
Is there any loraserver configuration or profile that need to be configured?


#2

Hi, I’m having the same issue here. Anyone knows why is it happening?


#3

The 902299987 Hz frequency is reported by the gateway so I would look into the the packet-forwarder code and / or configuration.


#4

Hi Brocaar,

Yes, the gateway is reporting the same frequency that the Lora node sent the transmission.

At the SX1276 specification (https://www.semtech.com/uploads/documents/an1200.24.pdf) the frequency deviation set to +/-25kHz.

So if I set the frequency at 902.3Mhz (902300000 Hz for channel 0) I can expected a frequency between 902275000 Hz to 902325000 for that channel. In this case, shouldn’t be better for the LoRa Server identify any frequency in that range as channel 0 of US_902_928 instead using the exact number that the gateway sent and not returning that error log message?

But I also agree with you to correct the frequency at the packet-forwarder before sending to loraserver.

Thanks,


#5

Hi, i’m having the same issue. I’m using Esp32 TTGO with LMIC for Node and ESP-1ch-Gateway-v5.0 Library for Gateway. Does anyone know why this is happening?
Output from Lora Server:


#6

This really comes down the the code you have managing the radio in the gateway.

The SX127x makes it possible to read out the frequency error, but it doesn’t mandate that a program do so or use that information.

In effect, whatever software your are using is being too clever for your needs; what you want instead is for it to just report the frequency the receiver was set to. This can then be used to lookup the corresponding downlink frequency.


#7

Thank you! I verified the code in gateway and fix the issue.


#8

Hey guys! I verified the code in my gateway and the frequency is set to 915 Hz as it should be but I keep getting this error: “run uplink response flow error: get rx1 frequency error: lorawan/band: unknown channel for frequency: 167260160”

Can anyone help with this? This would be much appreciated.

Thanks,

Delia