Hello. I have one node testing in a client facility and I loss some uplinks. I observe watching the gateway frame log that the losses are when other nodes from other networks are transmitting at the same time. I can see several frames from the other nodes instead of one of my node.
My node is sending in SF8 or SF9. The other nodes are SF12.
My Gateway is a Dragino DLOS8.
That losses supposes delay on the process information and it wouldn’t be acceptable for the client.
I see that my device has approximately in SF8: RSSI: -39 SNR: 7.5. In SF9: RSSI:-114 SNR: -7
The other devices in SF12 RSSI: -67 SNR: 11.8.
Three tests in the morning were ok. One test in the afternoon was not Ok. In different distances from the Gateway.
What could I do?
The only idea I have is to modify ADR algorithm and fix the nodes to send to the maximum power inside the DR removing the tx power adjust. I don’t know If that will make continuous DR changes.
My node is sending in SF8 or SF9. The other nodes are SF12.
With LoRa, packets using different spreading factors are orthogonal, meaning that they are invisible to each other: as mentioned earlier, they simply appear as noise to one another. Therefore, two packets that arrive at the same time on the same receive channel at different spreading factors will not collide and, both will be demodulated by the gateway modem chip. However, two packets with the *same* spreading factor arriving at the same time on the same channel **might** result in a collision. However if one of the two packets is stronger by six dB, it will survive.
more info:LoRa and LoRaWAN: Technical overview | DEVELOPER PORTAL
That losses supposes delay on the process information and it wouldn’t be acceptable for the client.
Don’t use Lora if the lost of some uplinks are a big problem.
Do some filter in gateway. Filter by DevEUI or NetID … it may help
Dont send uplink every 10sec at SF8 and SF9 and dont send “Confirmed Data Up” … that will also help
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Hello Daniel,
I am not sending every 10sec. I sent each minute. Confirmations are required by one of the applications. I know that Lora could not be the best option.
The SF12 devices appearing each 10-20 seconds are from a neighbor installation.
I know that orthogonal theory. Perhaps one simultaneous frame adds noise. Two simultaneous add so much noise that reduces the margin under the six dB.
I have the same problem. Interferences occur sometimes. Others it looks that they not interfere.
I don’t know if Disable ADR and using SF9 or SF10 fixed would be better.
In my device Rssi and SNR is very poor (-109 and 2). Is 350m from the Gateway that is indoor, not in a good place. It’s using SF8
The other devices signal is better RSSI: -43 and SNR 9.8. They are using SF12.
