Hahaha, nice idea comparing this tradeoff with the strength x speed capacity, @Epyon! Maybe you got my point here.
But my dilemma has both a practical and a philosophical question: I know that LoRa/LoRaWAN can handle my communication issue. I mean, I don’t need high data rate nor high volumes of data. But, I may need sometimes to send “big” data frames, let’s say of 100 - 200 bytes long.
One approach could be to limit my network architecture in order to have a link budget (dealing with distance and antenna gains) big enough to make sure that I can use a data rate that support this payload size.
The other would be to limit the payload (at my application) to the lower maximum payload possible (11 bytes on the AU915 channel plan).
So, in my oppinion, none of them are good options. At the 1st one we can’t take advantage of the great ability of LoRa about dealing with long distances, minimizing the quantity of gateways needed to cover an area. On the other hand, the 2nd approach leads to a subutilization and a very bad payload/overhead ratio wich obviously is a bad usage of the RF channel.
This leads to my current belief that the only effective approach being the packet fragmentation / defragmentation, so one can send bigger packages in any data rate / payload limitation, taking advantage of all LoRa capacities. If this is correct, I believe that LoRaWAN should provide a fragmentation standard so we don’t finish up with a lot of proprietary and uncompatible solutions. Also, having this standardized will lead to manufacturers and the developper comunity to integrate this on the stack, encouraging everyone to use it and therefore helping to achieve a better overall RF channel usage.