LoRa and GMRS?

[Blaise]

Hey, so My friends and I are building out a Meshtastic network with a bunch of cheap nodes built out of LoRa dev boards, solar panels, 18650 batteries, and Walmart plastic boxes.  They don't have the best antennae or the best chips, but you can build them for about $20 each, and scatter them *everywhere* (with permission, of course).

I had a thought about using this mesh, or one like it, to link GMRS repeaters to get around the hills and mountains we deal with here.  The data rates theoretically top out at about 5kbps, but that should be fine for raggedy old HT voice communications, and data is, well, data... 

Anyone given any thought (or practice) to building a LoRa/GMRS modem?

[SteveShannon]

51 minutes ago, Blaise said:

Hey, so My friends and I are building out a Meshtastic network with a bunch of cheap nodes built out of LoRa dev boards, solar panels, 18650 batteries, and Walmart plastic boxes.  They don't have the best antennae or the best chips, but you can build them for about $20 each, and scatter them *everywhere* (with permission, of course).

I had a thought about using this mesh, or one like it, to link GMRS repeaters to get around the hills and mountains we deal with here.  The data rates theoretically top out at about 5kbps, but that should be fine for raggedy old HT voice communications, and data is, well, data... 

Anyone given any thought (or practice) to building a LoRa/GMRS modem?

I believe that would not be permitted by the FCC’s interpretation of the regulations. 

[FishinGary]

I'm still learning Meshtastic myself, but I don't believe the packets are large enough to carry voice traffic in any usable form (but don't quote me on that). If you wanted to fire off quick messages during gaps in repeater coverage you could use canned messages. 

[WRYZ926]

Meshtastic is basically off grid texting and is limited to the size of messages that can be sent.

[Blaise]

16 hours ago, SteveShannon said:

I believe that would not be permitted by the FCC’s interpretation of the regulations. 

Well, as long as we keep in mind that Meshtastic is a mesh technology, not a network technology, I'm sure it will be fine... 

[Blaise]

1 hour ago, WRYZ926 said:

Meshtastic is basically off grid texting and is limited to the size of messages that can be sent.

If you use the libraries, you can get it to do a whole lot more, I'm told.  I'm not afraid of a compiler!

 

14 hours ago, FishinGary said:

I'm still learning Meshtastic myself, but I don't believe the packets are large enough to carry voice traffic in any usable form (but don't quote me on that). If you wanted to fire off quick messages during gaps in repeater coverage you could use canned messages. 

Every packet has a 237 byte payload, so you'd have to spend a lot of effort hacking the voice data into chunks, then reassembling them.  It might work, it might not, but it sure would be fun trying!  Also, GMRS data is likely only about 2 kbps, so there'd be plenty of room for at least that.

[WRYZ926]

20 minutes ago, Blaise said:

Well, as long as we keep in mind that Meshtastic is a mesh technology, not a network technology, I'm sure it will be fine...

You might get away with it is you do not connect the Meshtastic nodes to the internet. I would double check on the legality of this before proceeding if it was me.

 

11 minutes ago, Blaise said:

If you use the libraries, you can get it to do a whole lot more, I'm told.  I'm not afraid of a compiler!

This is true. But how many "non radio dorks" are willing to compile source code. If this were to be feasible and legal, then it would have to be made easy for all users to deploy. Not everyone is willing to even learn Linux let alone compile code.

[SteveShannon]

29 minutes ago, WRYZ926 said:

You might get away with it is you do not connect the Meshtastic nodes to the internet. I would double check on the legality of this before proceeding if it was me.

 

I absolutely agree about double checking the legality. Internet has little to do with this though. The fcc simply included internet because it is an example of “any other network.”  Originally the prohibition was against connecting to the phone network. 
 

“GMRS stations cannot be interconnected with the public switched telephone network or any other network for the purpose of carrying GMRS communications, but these networks can be used for remote control of repeater stations.”*
 

*The above is the FCC’s interpretation, not the actual regulations

@Blaise, arguing it’s a mesh, not a network, probably wouldn’t make a great first impression on the FCC. It’s funny though.

[Blaise]

5 hours ago, SteveShannon said:

arguing it’s a mesh, not a network, probably wouldn’t make a great first impression on the FCC. It’s funny though

You know, after I posted that glib reply, I started thinking (which is always super-dangerous, according to some people: People like my wife and closest friends!)...

Because of the broadcast nature of LoRa technology, where every transmission is just put out there with the hope someone will help you get it where it's going, I actually don't think it *does* technically fit the definition of a network!

[SteveShannon]

1 minute ago, Blaise said:

You know, after I posted that glib reply, I started thinking (which is always super-dangerous, according to some people: People like my wife and closest friends!)...

Because of the broadcast nature of LoRa technology, where every transmission is just put out there with the hope someone will help you get it where it's going, I actually don't think it *does* technically fit the definition of a network!

What word follows “mesh” when talking about “mesh networks“?

[Blaise]

2 minutes ago, SteveShannon said:

What word follows “mesh” when talking about “mesh networks“?

Just because lots of people are mistaken at once, doesn't mean they're right!

[SteveShannon]

36 minutes ago, Blaise said:

Just because lots of people are mistaken at once, doesn't mean they're right!

But when even the people who have the copyright on the name Meshtastic say it’s a network, the lone person claiming everyone else is wrong, and that it’s not a network, might have a problem proving he’s right. 

[Blaise]

Just now, SteveShannon said:

But when even the people who have the copyright on the name Meshtastic say it’s a network, the lone person claiming everyone else is wrong, and that it’s not a network, might have a problem proving he’s right. 

*Proving* it is an entirely different matter...