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BYOMesh – New LoRa mesh radio offers 100x the bandwidth

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Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#51

Post by golem14 »

lormayna wrote: post #27
mikeweiss wrote: post #23

Earlier quoted context omitted.

LoRa would go much farther than Wifi on 2.4ghz. Lora uses Chirp Spread Spectrum (CSS) modulation while wifi uses OFDM (Orthogonal Frequency Division Multiplexing). The first being designed for extreme range while the latter for bandwidth. At 2.4ghz you could probably get LoRa connections up to 6 miles with the right antenna height.

6 miles seems a very optimistic estimation: 2.4Ghz propagation is very reduced by obstacles like buildings or trees and at that frequency the atmospheric water (fog, rain, humidity) have a big impact on propagation. And you need also to consider that 2.4Ghz is a very polluted band, then the noise floor is significatevly higher than in the 865/915 Mhz. Moreover at 2.4Ghz the Fresnel window is smaller and the risk of m…

The record seems to be 830 miles (with antennas at sea level, no less)

https://www.thethingsnetwork.org/article/new-lora-world-reco...

But, that's receiving 3 of maybe thousands of packets.

There's work on bouncing of LoRA signals off the moon:

https://engprojects.tcnj.edu/lora-eme/

Yes, but Joe Shmoe won't see this on their home setup trying to talk to a buddy 2 miles away behind a hill.

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#52

Post by 01100011 »

igorramazanov wrote: post #41

That stuff is good for drone warfare, mesh networks already been used in Ukraine E.g. drones geographically organize themselves into a chain with each of them serving as a mesh-network node, then each of them, including the tip of a chain, can be controlled by operators, and the whole setup is a closed network which works without requiring Internet access

Something like Trellisware's TSM waveform would be a better fit:

https://trellisware.wpengine.com/waveforms/tsm-waveform/

Nodes can cooperate to beamform and reach greater distances.

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#54

Post by drgone »

mikeweiss wrote: post #42
dheera wrote: post #37

Earlier quoted context omitted.

Just use Unifi Airfiber for 6 miles at gigabit speeds. If you're relying on line of sight then 2.4GHz is nonsense. And if you don't have line of sight then no you're not getting 6 miles

Is UniFi Air fiber extremely low power and cheap to produce?

yes, considering the options.

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#55

Post by wiml »

amelius wrote: post #48
ninjagoo wrote: post #47

Earlier quoted context omitted.

> That stuff is good for drone warfare > each of them serving as a mesh-network node might have worked for a bit in the past, but is easily disrupted by jammers, and forced a switch to fiber-optic in-theater. People have learned from that and don't bother with radio anymore, even in new theaters.

How about spread spectrum techniques?

LoRA is a spread spectrum chirp modulation already.

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#58

Post by refulgentis »

nunobrito wrote: post #38
refulgentis wrote: post #30

Earlier quoted context omitted.

Gonna reply here, but this isn't about you or this post: HN has a lot of us that have ~0 idea what you'd use this for, even when we steelman, all we can do is vaguely handwave about easier to setup wireless internet on a vast compound we own. Would be really cool if someone could hop in and just give a couple one off examples, i guess? Only other one handwave I can think of is IOT x assembly line stuff for businesses…

You'll read a lot of illusions and wishful intentions. In the end: LoRa is only good for very short text messages at somewhat long distance (up to 10km without special setup) and without bad conditions (obstacles on line of sight, rain/fog). There is an ongoing fight between each of the two frequencies to be used as default and this publication adds another frequency into the battle. There is WiFi HaLow, a relatively…

Cheers, there's nothing more valuable than an opinionated overview from someone who groks the domain

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#59

Post by jauntywundrkind »

lormayna wrote: post #27
mikeweiss wrote: post #23

Earlier quoted context omitted.

LoRa would go much farther than Wifi on 2.4ghz. Lora uses Chirp Spread Spectrum (CSS) modulation while wifi uses OFDM (Orthogonal Frequency Division Multiplexing). The first being designed for extreme range while the latter for bandwidth. At 2.4ghz you could probably get LoRa connections up to 6 miles with the right antenna height.

6 miles seems a very optimistic estimation: 2.4Ghz propagation is very reduced by obstacles like buildings or trees and at that frequency the atmospheric water (fog, rain, humidity) have a big impact on propagation. And you need also to consider that 2.4Ghz is a very polluted band, then the noise floor is significatevly higher than in the 865/915 Mhz. Moreover at 2.4Ghz the Fresnel window is smaller and the risk of m…

I have skepticism too. But also, from a recent LoRa thread, and talking about 900MHz here, but someone said:

> Wifi HaLow 802.11ah. LoRa is another level. It works down to -146dBm. 802.11ah dies around -100dBm.

https://news.ycombinator.com/item?id=47890598

LoRa looks like someone is dropping a saw wave on the spectrum. It so clearly looks like such a blunt force user of spectrum. Just wild.

Re: BYOMesh – New LoRa mesh radio offers 100x the bandwidth

#60

Post by bigfatkitten »

kanbankaren wrote: post #35
jtchang wrote: post #11

Correct me if I am wrong but I thought the primary appeal of LoRa was range? Also isn't the primary factor in making long range radio go through things is the frequency? So 2.4ghz is the same frequency as consumer wifi right and thus would propagate about the same right? It doesn't seem like this would be that useful except that the protocol is LoRa so you can have higher bandwidth between two devices if they happen…

> would propagate about the same right? No. Free space loss increases with frequency. FSP loss for 915 MHz at 10 kms is ~ -111.67 dB while for 2.4 GHz is -120 dB. That is a 9 dB loss which is significant. It could mean the difference between a copy or just plain static though the LoRa is supposed to be copyable down to -140 dBm. The max tx power is around 150 mW (21.76 dBm), so at 10 kms, the RSSI is 21.76-120 = -98.…

LoRa is copyable at -140dBm only at very low effective data rates (under 100bps), which for many applications is too low to be useful.
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