Expected Range and Suggested Settings

[egarl004]

Hey everyone, just getting up to speed here and was wondering if anyone could point me in the right direction. I've successfully gotten point to point comms working using the example in the lopy documentation (the ping - pong scripts), however, my range is awful. Well at least to the advertised ranges. Im seeing about 0.8km. (I've mounted one node to the top of a pole about 30 ft above ground level, low buildings yet urban environment) I've played with sf, bandwidth and tx power settings and the interesting thing is that no changes make any difference whatsoever. I'm in the US for reference. Anyone have any ideas to improve my range or correct settings I should implement?

Here's one of my node's code:

lora = LoRa(mode=LoRa.LORA, sf=12, bandwidth=LoRa.BW_125KHZ, tx_power=20)

[bmarkus]

Did you connect any antenna to the boards?

[egarl004]

@bmarkus yes. both with the included antennas at the antenna mount location left of the RGB LED when held vertically with the RGB LED at the top.

Edited for clarity.

[livius]

Only better directional antenna

[bmarkus]

What is about line of sight? Can one antenna see the other optically or there are buildings inside? While LoRa is great, it is 'just' a radio. Try other positions, relocating antenna by 20-30 cm can change the situation. Also our experience is that reflection from large object like building, farm silo, etc. may help.

[egarl004]

@bmarkus thanks for the advice. I'll try moving it around and post my results. I found this "calculator" and seems to be accurate to my antenna positioning. Link Labs Range Calculator. My node was inside a car driving around and stopping every 100m. Essentially, my node's antenna was on the ground.

[egarl004]

For everyone's information, I was able to move the antenna around and get much greater point to point distances. Generally 4.5 km based on the environment. Thanks for the input!

[borjam]

@egarl004 In any radio application, the antenna is a really critical part.

It will be usual for LoRa antennas to be on the ground, but gateways should be well positioned with good antennas. Look for antennas with a low angle of radiation (which means they will have gain) and, if you aren't placing the gateways centered in the area of interest, directional antennas.

Whenever one says "antenna gain" most people thinks about transmission power gain. Actually, antenna gain means that the sensibility of the receiver increases and it rejects noise much better.

Depending on your needs, look for collinear vertical antennas or even sector antennas.

[livius]

@borjam said in Expected Range and Suggested Settings:

Depending on your needs, look for collinear vertical antennas or even sector antennas.

Sector antenas are really good choice
also it is possible to buy quite good antenna on alliexpres for good price :)

[borjam]

@livius But beware dodgy antenna vendors. I've seen real abominations coming from China, with imitation N connectors even! I remember a shipment of antennas, all of which measured very different when tested with a VNA.

I have seen good antennas coming from China, but they were not cheap.

Unless you know very well what you are doing, I would recommend you to stick to proven antenna providers. Personally I can recommend two in Germany: Round Solutions and Wimo.

A good hint to identify proper antennas is a good datasheet including a S11/Return loss/SWR graph.

And if you want to test the antennas yourself, Mini Radio Solutions sells a very affordable VNA (miniVNA Tiny) that really works.

And for anyone interested on learning about the subject I can recommend Joseph Carr's "Practical Antenna Handbook". Beware, antenna design is a complete career path by itself, unless you are deeply interested on the subject you better skim through some sections of the book. But it will help you gain some "instinct" to identify "by heart" what might work and what won't.

The ARRL antenna book is an interesting book as well.