[MVMA] LoRa

Mon May 3 14:50:59 EDT 2021

Hi Chuck,

Glad you like his paper. I listen to one of his presentations as well. He’s pretty good about saying what he has not proven or knows. I believe he is talking about some of the types of mesh’s and there up and downsides. It's not a competitor to AREDN. Its scope is much different.

The comparison is WIFI vs. LoRa they utilize different modulation techniques. There is no question that WIFI today is incredibly faster than LoRa. WIFI initially only did 2Mbit they are very different technology and purpose. The WIFI on introduction was only 2Mbits/s; today, it 10Gbit/s+.  It too early to know where LoRa ends up. My guess they will fill different niches—possibly never close to wifi speed. LoRa is chirp spread spectrum modulation technique. I understand the principle and generally how it works. The deep detail is beyond me at this point. Some guy has been able to get LoRa to transmit 200 kilometers off a mountain top. I don’t know that proves anything other than near perfect condition you can send a single a long way. WIFI maybe able to do the same or better. I don’t know or care. Im looking at LoRa for its ability to run under very low solar power footprint. We’ll soon find out if that is true.

I believe any effort around LoRa would not compete or rival the AREDN. if anything, AREDN could be used as a backbone. It would be great if AREDN could expand out much more. John is coming over tonight to see if we can get the loaner to reach MVH. 

To reference your note, LoRa does not rival AREDN. The only thing that compares would be Qmesh. Which at this point is not a rival and may never be. If LoRa technology became so good AREDN potentially could get modified to use it instead or in addition. No idea of the feasibility of such a concept.

I received two knock-off Audino boards with LoRa chips and crap antennae. I hope to install Meshtastic on them this week. Some other HAMs have already they this concept a bit further.  A big win for my short-term goal would be to have an app that sends messages between multiple audino boards with LoRa chips 2 miles or more on solar power. My interest is communicating when we lose the regional grid due to a significant outage. Unfortunately, it’s a matter of time, not if it will happen.

My understanding is that someone has already extended out an AREDN network with sensors using LoRa. I have not dug into that yet. It could be for monitoring something like a balloon.

I understand Dan Fray’s interest is to extend out current HAM radio handhelds by creating repeaters that would use LaRo and  Qmesh. I’m going to send him an email with questions when I get a bit further using the technology.

Bob French PMP, ACP

AC8ZU

From: mvma-bounces at mailman.qth.net <mvma-bounces at mailman.qth.net> On Behalf Of Chuck Gelm
Sent: Monday, May 3, 2021 10:43 AM
To: mvma at mailman.qth.net
Subject: Re: [MVMA] LoRa

On 4/29/21 2:52 PM, bobf at omegaiq.com <mailto:bobf at omegaiq.com>  wrote:

QMesh: A Synchronized, Flooded Mesh Network Protocol for Voice <https://files.tapr.org/meetings/DCC_2020/2020DCC_KG5VBY.pdf>   by Dan Fray, KG5VBY

Hi, Bob:

 That was a fun read. Thanks.

With the AREDN firmware the routing is automatic-adaptive.
So, regarding the local implementation of our AREDN mesh network,
these 2 lines in the above document contradict:
Page 3/17 [115]:
Typically, mesh networks can handle nodes entering and leaving the network while still maintaining a functioning network.
.vs.
Page 4/17 [116]
Routed protocols, where nodes only repeat packets if they are along a defined route, are more efficient, but more challenging to build and maintain working routes at network conditions change.

Open source 'Automatic-Adaptive routing protocols' have existed since circa <= 1989.
Currently this AREDN firmware [circa 2015 to date] has a self-building and self-healing routing protocol.
This feature comes with
- reduced throughput and
+ freedom from needing to maintain route configurations.

LoRa: up to 27 kbps and long range is up to 10 km under 'perfect conditions'. Can handle 1 voice grade channel.
AREDN firmware: up to 130,000 kbps and long range is up to 50 km in practice. 

AREDN compatible devices are off the shelf, many commercial grade, many outdoor rated, and $50 and up.

Chuck

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