Hi Everybody,
Perhaps someone knows if I interpret the following situation correctly or how it might be resolved.
When I’m in the vicinity of my brand-new TTIG, my test device joins successfully and the messages get to the application without any problems, for both SF7 and SF9. The device is a TTGO T-Beam with a tracker SW for TTN Mapper.
When it has already joined and I go further away, messages are received by my TTIG and by another GW about 1.5 km away for SF9 (and sometimes also SF7). RSSI and esp. SNR are usually higher on the distant GW. ADR is switched off.
The problem is, that the device cannot join the TTN when in reach of both GWs and not close enough to my own TTIG. When an automatic re-join is attempted, the device looses connection.
The console shows, that the join request is received by both GWs and the SNR/RSSI is better for the distant GW. I can also see that my own GW does not send a join accept, so I assume that it has been sent by the distant GW and my device was not able to receive it. Either the distant GW can receive better than transmit, or, my device can transmit better than receive.
Console with two failed join attempts
Both attempts look successful on the console.
Application:
My gateway (join requests visible, but not join accepts):
Details from the console for the first join attempt
Application (the first GW in the list is the distant one, the second eui-58… is mine):
{ "time": "2019-11-24T15:15:20.596248692Z", "frequency": 868.1, "modulation": "LORA", "data_rate": "SF9BW125", "coding_rate": "4/5", "gateways": [ { "gtw_id": "eui-b827ebff...", "timestamp": 178502364, "time": "2019-11-24T15:15:20.5656Z", "channel": 0, "rssi": -103, "snr": 10, "rf_chain": 1 }, { "gtw_id": "eui-58a0cbff...", "timestamp": 39487572, "time": "1970-01-01T00:00:01.57460852Z", "channel": 0, "rssi": -106, "snr": 3 } ] }
My Gateway eui-58a0…:
{ "gw_id": "eui-58a0cbff...", "payload": "...", "dev_eui": "003BA610...", "lora": { "spreading_factor": 9, "bandwidth": 125, "air_time": 205824000 }, "coding_rate": "4/5", "timestamp": "2019-11-24T15:15:20.646Z", "rssi": -106, "snr": 3, "app_eui": "70B3D57E...", "frequency": 868100000 }
What can be done to fix the situation? Going back from OTAA to ABP does not look like a good solution…
I hope the category is correct for this topic, but it’s about two gateways, so
Regards,
Holger