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Comment by chuckledog | Hacker News Reader

Some context: LoRa is a new, private and spread-spectrum modulation technique which allows sending data at extremely low data-rates to extremely long ranges. The low data-rate (down to few bytes per second) and LoRa modulation lead to very low receiver sensitivity (down to -134 dBm), which combined to an output power of +14 dBm means extremely large link budgets: up to 148 dB., what means more than 22km (13.6 miles) in LOS links and up to 2km (1.2miles) in NLOS links in urban environment (going through buildings).

From https://www.cooking-hacks.com/documentation/tutorials/extrem...

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OP observed up to 20x that range https://www.distancefromto.net/distance-from-sheffield-gb-to...

And all of these range examples are completely irrelevant to the distances you'll achieve using lora in practice. But while we're on the subject there's been lora from/to geosynchronous orbit. So I think that's the distance record: https://hackaday.com/2018/02/22/at-71572-km-you-wont-beat-th...

At VHF and up the only thing that really matters is line of sight. Everything else modulation wise is just frosting. Unless you're in a plane/balloon/etc or paying for power and location on a very tall building Lora isn't going to go any further than your 2.4 GHz wifi router.

These contrived setups for distant records (and using transient tropo ducting) are just for fun.

While I agree the sentiment that the silly range ones are just for fun, I have in practice seen good links over ranges with no line of sight.

I've personally observed links through many buildings, over hills, and so forth that easily dwarf the range of the average 2.4Ghz link.

950Mhz/860Mhz is fine, 315/433Mhz is even better for longer distance but it seems Europe/USA are mostly 950/860Mhz only.

I see your 71572km and raise you a 3.5W radio signal received on Earth from the distance of 1.2 billion km: http://www.planetary.org/blogs/emily-lakdawalla/2005/2005020...

Impressive, but the linked article didn't uses a high gain antenna array like was used to communicate with deep space probes.

They specifically wanted something with a low barrier to entry. Take a look at the antenna they used. Pretty impressive imo.

If I read that right, they used a GEO satellite as a relay, which is nothing like a low-power device, and GP's point was the asymmetrical distance record. Similarly, Hyugens experiment used a simple patch antenna at Titan (that's why it's notable), and a high-gain antenna on Earth.

Guess I should have read further in.

That's not lora modulated. My example was.

To me, this is not extremely long range, in comparison to a Pactor modem over HF, which can reach over 1000 miles, as I've seen on a sailboat passage from Hawaii to California. It requires more power - 150 watts or so, if I recall correctly, and bit rates can be low as a few bits (not bytes) per second with poor propagation. Being able to stay in contact with family in the middle of the Pacific Ocean is pretty awesome.

Right but this is for edge devices that can be battery powered. You can't use 150 W.

Not just battery powered but battery powered for months+. The way that receive windows are structured into the protocol it allows the device to go into deep sleep between windows.

I believe the selling point is that it can run on battery for years, 10+ years sometimes limited by battery's shelf life time.

"Not just battery powered but battery powered for months+"

True, and solar powered too, that is, put one on a pole and forget about it; not even the cost of changing the battery, just wiping the solar cell now and then if wind and rain don't do their job. The rechargeable one can be a supercap or an oversized cell so that when time will inevitably degrade its chemistry to an unusable state, the sensor will probably have ended its planned use life already.

You also have to have appropriate licensure at that power output.

It's extremely long range for low-power devices. LORA is mostly used for sensors, trackers and other miniature, usually battery/solar powered devices that need to run for months or sometimes years unmaintained.

Also, very small antennas, especially compared to typical HF antennas (sometimes the entire 60+ ft backstay on a sailboat, for example)

For those interested in playing around PyCom (MicroPython devices) are great. As an example the LoPy 4 supports LoRa, Sigfox, Bluetooth and Wifi.

https://pycom.io/product/lopy4/

I got one of those but only having one. I can think of some uses for it if I had two but with only one, couldn't do much with it.

Keep in mind that's not exactly true. There are gateways that can be used such as "The Things Network": https://www.thethingsnetwork.org/

150 watts is 5000x more power than what LORA requires, which is why this is so impressive.

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