Main Question:
Is my list complete of radios that can do mavlink telemetry in a mesh network and is there any that standout as ones to choose/ ones to avoid? (I noticed that Xbee was listed as not recommended in the ardupilot documentation, but I do not know why)
915/868 MHz Frequency
RF Design 900x radios with mesh or asynchronous firmware
Holybro Microhard Telemetry Radio
XBee XR 900/868 or 900HP radios
Meshtastic radios?
2.4 Ghz
XBee 802.15.4 or DigiMesh radios
Meshtastic radios?
433Mhz
Meshtastic radios?
Not very certain on the meshtastic telemetry. From my beginner standpoint it seems all the requirements are there to do mavlink comms. And meshtastic seems like a hot topic right now. Someone please tell me if I am wrong!
Background information
I have been playing around with mesh networks for mavlink telemetry for swarms.
These are the options I have come across so far. I am thinking of having a primary and secondary swarm connection on my vehicles. I was thinking a god way to do that would be to have them on different frequencies right? like have one mesh network at 915MHz and another at 2.4 GHz? That seems the easiest route to avoid interference
I have come across the doodle lab mesh rider radios (but… that is very pricey, outside of my personal budget)
I also came across mLRS radios - but my understanding is that those are just point to point. Someone please correct me if I am wrong!
I did a lot of multipoint/mesh network testing and this is what I think:
Configuring and managing the radios systems can be very challenging when conducting swarms, but the TLDR is:
Meshtastic is too slow to be useful for Mavlink
Zigbee is not very powerful and not well designed for Mavlink serial messaging and can struggle.
WiFi-based multipoint networking such as drone bridge or kahuna has better support for Mavlink messaging but can be limited in output power and thus range.
RFDesign has new multicomm firmware for their RFD900x2s and ux2s and it’s pretty fast if you set it up correctly. Setting up mesh was confusing though.
Microhard M900s have a mesh functionality that were pretty finicky but worked.
IP MANET radios such as Doodle Labs are much easier to set up true mesh networking and have the potential of incorporating other IP-based data such as video and companion computer, but are very expensive.
For local multipoint/mesh networking, limiting data rates, limiting node hops, reducing interference, and optimizing the radios as best as possible is the most important for good swarm communications.
One thing I never tested but in theory could work quite well depending on legalities and cost is telemetry over LTE. I’ve tested a single LTE drone in an area with ok cell service and I’m pretty sure there would be pretty good overhead to run a bunch more.
Well said, @ceating completely agree.
I’ve tried RFD multipoint and Multicomm, both were tricky to keep stable, while DroneBridge was much easier to run.
I also think LTE + Tailscale + MAVLink Router should work fine with decent coverage.
By the way, is there any simple way in Follow Mode to confirm that one vehicle actually receives MAVLink data from another’s sysid before flight? I’d like to add that to a pre-flight checklist.