[aprssig] LoRa iGates are inserting RSSI & SNR in comment

[Borja Marcos]

> On 29 May 2024, at 00:23, Heikki Hannikainen <hessu at hes.iki.fi> wrote:
> 
> 
> Hi,
> 
> Just for wider awareness:
> 
> Some LoRa APRS iGates are inserting RSSI & SNR values in the comment text, creating duplicate packets.
> 
> Here's one example where each single packet is multiplied into three different packets, because it reaches three igates. One iGate doesn't modify the packet, the two others add different RSSI & SNR values.
> 
> https://aprs.fi/?c=raw&limit=&call=OK2ZAW-17
> 
> 2024-05-28 21:54:33 EEST: OK2ZAW-17>APLG0,qAO,OK1FWG-10:=5016.90NL01625.35E&LoRa sun DiGi
> 2024-05-28 21:54:33 EEST: OK2ZAW-17>APLG0,qAS,OL7M-10:=5016.90NL01625.35E&LoRa sun DiGi DP_RSSI: -99 dBm DP_SNR: 9.75 dB
> 2024-05-28 21:54:33 EEST: OK2ZAW-17>APLG0,qAS,OK2ZAW-18:=5016.90NL01625.35E&LoRa sun DiGi DP_RSSI: -111 dBm DP_SNR: -15.25 dB
> 
> Naturally each different iGate injecting a unique RSSI value will create another duplicate. I'm now dropping these corrupted packets at aprs.fi.
> 
> There's some discussion on this here:
> 
> https://groups.io/g/APRS/topic/lora_aprs_igates_and/106326352

There are several poor practices linked to LoRa right now. Not only that, but there is an assumption that certain to_calls identify LoRa equipment, which is not true.

Given that now APRS supports different modulation techniques it would be wise to rethink the iGate protocol in a backwards compatible way
allowing the inclusion of out of band “labels” identifying modulation technique, signal quality values such as RSSI and SNR (or others), frequency band, etc.

That information is mostly useless for iGates but that enrichment can make the information stored in backend databases such as aprs.fi <http://aprs.fi/> much more useful.

What about a small workgroup and putting up a proposal?



Borja / EA2EKH.