One of the biggest issues is LoS, as the 800s 900s mhz are terrible at passing around buildings, hills, or even trees. The result is, in reality, most people living in urban or not, can not get the device to connect to a friend’s house like 2kms away (unless they live on the top of the mountain having great line of sight), making the project somehow useless (or only useful to very limited tasks)
My understanding is, the 169MHz (close to FM radio) does a much greater job at transmitting data in real complex world. But why no one is using or talking about it?
Furthermore, why don’t we use the AM radio range like 1000kHZ that goes through buildings, hills and even underground, that we can cover a super large city with few devices easily. What limits us from doing that?
In a lot of case you really do want to limit connection distances, this allows very limited frequency allocations to be shared by more people.
If for instance all those RF remote controls, fire alarms, burglar alarms and the like used lower frequencies with much longer range, they would all interfere with each other.
In your part of the world is there an un-licensed frequency allocation in the 169Mhz region ?
Reducing the distance by reducing the power is never been the issue.
In reality, I highly doubt anyone really care about this beyond paper works. The output power of lora is in the so pathetic scale of 0.0x watts that, my old microwave oven is leaking 10x radio wave more than it… And we are talking about go off-grid.
Even if thats the case in practice, the devs have to abide by the rules. They would be breaking the law and sooner or later it would be shut down. Lora is a standard and they go with that.
actually i am quite pissed, because somewehere near me there is a setup that does not seem to care about the paper works …
there is a signal , exactly on eu868 frequnecy, broadcasting an almost constant signal, blocking about 60+% of airtime… the result is, that my roof-top-mounted node is almost deaf and can only receive signals from about 2-3km distance… i have to find a place that is protected from this signal, and put up a node there to receive anything here…
and its not a kitchen device, its some directional antenna pointing at my place from some kms away !, the provider who is running that system has already been contacted.
I check the government radio frequency assignment chart. There are plenty of free-use and/or the amateur radio frequencies in all kinds of frequency group, even for the super long wave lengths.
We don’t need to go illegal, even I thought like 0.02w output nobody cares. (Also that’s true that, in some countries the law says under 20mW or 10mW it’s not treated as broadcasting, don’t need to follow any regulation. Usually it’s said indirectly, like if over 20mW you must have a license etc etc then no mention about the under 20)
Anyway, in theory, the wavelengths close to the the AM radio it travels much longer distance and it travels through all buildings and small hills. It is slow for low power devices but should be ok for text.
But, we don’t have cheap hardware like lora and software to utilize it.
Also, I think the Lora (IoT devices originally) design engineers choose not to use those “much superior” frequencies for some reasons I don’t know yet.
