That distance you are quoting can be achieved, with the right spreading factor so you know. The smallest spreading factor (I think SF7) has the lowest power and the minimal amount of error correction, but you have the maximum amount of times you are allowed to send it. SF12 uses increased power as well as increased error correction, so it would be able to go the most distance. Sometimes you are lucky, with SF7 I have had a packet received more than 20km away, but in general you would tend to go for a higher spreading factor as you would not be transmitting at a high rate I expect. Lora is great!

Along with what Kim said, I would be careful in believing those numbers without actually testing for yourself. Wireless range estimates are notorious for being extremely optimistic. 

If you are using a tracking collar with a small antenna, ie: a chip antenna on the circuit board, and then a base station with a large antenna, ie: a YAGI, you would not get the ideal range. Small antennas are omnidirectional which means their power is spread in all directions. So only a small fraction of the power will go towards the base station antenna. 

Also, if you are in an area with dense canopy, ie: tall grasses, trees, leaves, etc, your range will be compromised as each obstacle the signal passes through will attenuate the signal.

There are so many factors that go into wireless communications range and most people only report their best results. My rule of thumb is to take an optimistic figure, like X kilometers of range, and divide by 10. That would give a realistic estimate of reliable range with some link margin to play with.

This is a bit pessimistic, so what you may want to do is get some cheap LoRa radios and have them transmit to each other. Then do a range test with them in the area (or similar) you are planning to deploy. This would give you a more realistic feeling for the kind of distances you can expect. 

Hope that helps somewhat and I'm not being too much of a downer.

Akiba

Hi @ONCA, you could talk to the folks from TagRanger, such as Craig Rackstraw (@craig). There's a thread here about their tags and a talk from Craig here. 

Cheers,

Rob

Hi Andres!

I have only little experience with LoRa myself but according to Robin Sandfort @capreolus, LoRa transmission suffers a lot in heavilly vegetated habitats.