New type of 2 way radio

[Flashpoint]

I know a little about radio because I used to troubleshoot radio frequency test equipment, but I have never taken the time to come up to speed on ham radio, etc.

So I'm not qualified to evaluate this, but I assume it has value in a SHTF scenario. Hopefully it's informative to some here and maybe even someone can give a cliff notes version of what this is good for (if anything).

 

[mostly22lately]

Oh, 900 MHz LoRa ... where to start ...

Most of the video is hyper-computer-techie mumbo-jumbo, discussing how to load software that someone else wrote, over the internet, into your supposedly encrypted Bluetooth-extended 300 milliwatt 900 MHz FHSS mesh data modem made in China.

Almost nothing of the video up to around 22 minutes covers actual communications, and lots of the terminology is incorrect.

To get to some sort of answer to what you want to know ... listen starting at 22:21

In your SHTF scenario, what problem, exactly, would you be trying to solve?

If you say 'lack of communications' that is an interesting response but it's far too broad a term to be helpful in defining what you need.

If you then say "I'd like to replace the functionality of my cell phone" then LoRa isn't going to do that, not by any means.

 

[htperry]

I have two Meshtastic nodes, one at home and one at work. It is a LoRa implementation of a text-only mesh network.

This is pretty well along in the EU and is just now taking hold in the USA. The mesh networks around here are pretty spotty and will only fill-in with more adopters and patience.

 

[MacEntyre]

So I'm not qualified to evaluate this, but I assume it has value in a SHTF scenario.

Quite an assumption.

The title of that video kinda says it all...

 

[Flashpoint]

My interest was in a secure encrypted/un-monitorable communication channel, ostensibly to communicate with observation posts or patrols. Would not want to use repeaters but would only need 1-2 miles range.

 

[noway2]

My interest was in a secure encrypted/un-monitorable communication channel, ostensibly to communicate with observation posts or patrols. Would not want to use repeaters but would only need 1-2 miles range.

Without delving into the video, what I suspect you stumbled into is the idea of a point to point mesh network. These have gained a lot of popularity in places like Taiwan where the CCP tried to shut down commas by disabling the cellular networks (same effect as a grid down and their generators run out).

The idea being that instead of using a centralized hub for communication, that the devices form a mesh such that if a wants to talk to z that in can hop traffic from one host to another and ultimately do so.

The problem is getting enough devices over a coordinated geographic region to establish said network. In a leftist resistance like in a Taiwan where they’re all concentrated in a particular area, that is feasible. Spread out sponge your and your neighbors homestead, not so much.

 

[mostly22lately]

My interest was in a secure encrypted/un-monitorable communication channel, ostensibly to communicate with observation posts or patrols. Would not want to use repeaters but would only need 1-2 miles range.

Every node in the mesh is a relay (not a repeater, which is a full-duplex device). If the nodes are also the mesh participants and they're moving around, the mesh maintenance will consume a larger part of your already-very-limited bandwidth, not to mention power budget.

[Yeah, all the dirty little secrets of mesh tech. By the way, I operate a 900 MHz mesh network at my house, with more than 60 nodes, and I was the CTO and co-founder of a venture-backed firm that for almost a decade manufactured a 900 MHz distributed-radio telemetry system.]

I'll assume because you said you would not want repeaters that you would not want to pre-install mesh nodes to cover the geography you want?

The Meshtastic system described here is for short text-only message; no voice. Did you want voice?

How 'unmonitorable' does your setup need to be? Do you mean, not casually eavesdropped? Or, actually encrypted?

When you say "1-2 miles" you'd need to specify much more information, such as, are the participants inside buildings or outdoors, or both? What is the topography and what is in/on it? Are the participants on foot? In vehicles? Both? Are the participants expected to carry the communications device in their hands or on their person (this distinction helps manage fade margin)?

The reason to become a ham radio operator is to be able to learn about all the things you'd need to know to build an effective system such as what you're asking for. You can't actually DO what you're describing using ham radio but the principles all apply.

 

[noway2]

The reason to become a ham radio operator is to be able to learn about all the things you'd need to know to build an effective system such as what you're asking for. You can't actually DO what you're describing using ham radio but the principles all apply.

And you’ll have access to a vast knowledge base of experience that has experimented with all sorts of technology and is willing to share that knowledge. .

 

[Button Pusher]

Reminder that amateur radio transmissions can not be encrypted.

 

[georgel]

Reminder that amateur radio transmissions can not (legally) be encrypted.

 

[htperry]

Reminder that amateur radio transmissions can not be encrypted.

Meshtastic isn't exclusively ham radio frequencies and is primarily on ISM bands.
The default in USA is encrypted unlicensed 915 Mhz ISM band.

 

[htperry]

I look at it as all "radio" and my interests aren't pigeonholed into ham radio as the end-all, be-all.
I think rather than being a detractor for non-ham radio interests - use it, don't use it.
It doesn't negatively impact anyone to play "radio" as a non-ham.

 

[mostly22lately]

an article of some interest on the topic of Meshtastic security, from last month:

Enhancing Security and Trust in Internet of Things through Meshtastic Protocol Utilising Low-Range Technology

The rapid proliferation of Internet of Things (IoT) devices has raised significant concerns regarding the trustworthiness of IoT devices, which is becoming a crucial aspect of our daily lives. In this paper, we deal with this important aspect by taking into account Meshtastic, a dynamic mesh...

www.mdpi.com

also, of note....

the 902-928 MHz radio spectrum in the US is allocated for:

RF Devices (Part 15)
ISM Equipment (Part 18)
Private Land Mobile (Part 90)
Amateur Radio (Part 97)

So, Meshtastic defaults to using the US ham radio band at 902-928 MHz.

Meshtastic is Part 15 'unlicensed intentional radiator' type authorization. Meaning it follows the law that states, in part:

"... nonlicensed devices must not cause harmful interference to, and must accept interference from, authorized radio services"

Meaning, if a ham repeater was nearby, Meshtastic gear might not work well in that immediate vicinity if the hams were on the air.

Part 18 covers devices like diathermy; these are not communications devices. Same sort of problem ... interference can easily wipe out the mesh and cause it to rebuild.

Authorized radio services in this band are Part 90 (land mobile, a.k.a. two-way radio, pagers) and Part 97 (ham radio). These have use priority over the Part 15 devices.