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IP over serial RF modems: possible? how?

IP over serial RF modems: possible? how?

IP over serial RF modems: possible? how?

I have a number of entities each equipped with a Digi X24-019PKC. Which is an RF serial modem.
These are able to mesh, effectively building a wireless bus in which every message sent by any modem is received by all the others linked on the same channel.
The protocol under all of this is proprietary and unaccessible, but this is not the point.
What I would like to do is bind these modem to an Ethernet address.
Since functionality provided is practically the same of a network card, is there any protocol that does this?
It's a kind of IP over Serial, but not PPP because it's multipoint.
Doing this would allow me to use network libraries to set up sockets, client/server mechanism and all the likes, makeing it much more easy to mesh multiple entities together sans wires.
Using Wifi is out of the question as it does not possess the necessary range.
Also changing to another modem which does provide long range and ethernet is a possibility too distance because of funding problems.
So does anyone have any idea if and how this is possibile?

RE: IP over serial RF modems: possible? how?

Not sure what would be the point, since your hardware is designed to implement essentially an RS-485 interface.  Whatever you do outside of the modem has to be converted to serial just to talk to the modem itself.

Can you exchange the modems for the Ethernet version from the same manufacturer?


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RE: IP over serial RF modems: possible? how?

The manufacturer -E (for ethernet) devices are nowhere to be found (listed only as legacy products) and besides i cited funding as a main problem (i can't right now buy new modems and have to do with what i have).

The modem itself is a serial passthrough. It does not answer to AT commands unless you enter a specific string with specific guard-times (impossible unless explicitly wanted). So whatever is the input in one modem, is the output of all the others. Shared bus link.
The scenario is a multibot scenario, where each robot has to communicate with the swarm and the remote operator.
Now implementing such a protocol anew would be an intensive task, as it should provide IP-like features.
So tunneling the IP protocol over the serial interface would, in my opinion, provide a solution.
Also I'm based in Italy where long-range RF modems using the 900Mhz band are forbidden as the spectrum is reserved. And unfortunately most ethernet modems i look up are on the 900Mhz band (aside from the fact that i can't buy them).
So is there a way to manually tunnel IP traffic on a com-port? Or can you think of any other advice?

RE: IP over serial RF modems: possible? how?

The wireless serial devices mentioned are basically point to multi-point wireless modems. This does not work well in a strict IP environment. What would be required are devices to convert IP to serial (like a CSU/DSU or a terminal server) and a device to control the routing of the traffic in a point to multi-point serial environment.
Basically, put a router at each device.

Avocent has a single port terminal server that was originally developed by Cyclades (before Avocent bought them out), that runs on their version of Linux. It is a TS-100. I am not sure if they still make them, but they are available at several places online. A representative link is below. If you have any experience in Linux, you can modify and recompile the firmware to make the device act like a router. This may do what you are looking for. We modified a TS-100 to rout traffic over a serially connected dial up modem when we lost our primary Ethernet transport. I think it is doable.



RE: IP over serial RF modems: possible? how?

You can do pretty much anything you want, IP is a multilayer protocol, and so long as the drivers can insulate the hardware from the protocol drivers, the result should be transparent.  They run IP over power lines, after all.

However, that said, your modems are outrageously slow for modern communications, and adding the overhead of IP on the interface could potential drive performance into the ground.


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