Mavproxy, 2 ground stations, 1 drone

Hey guys :wink:

Weird question as usual… If I setup two ground station telemetry transceivers with the exact same setting, NetID, canal, etc… Will I be able to connect, receive data and send order with both at the same time with Mavproxy?



Yes, and there will be some collisions and other bandwidth eating phenomena during some tasks.
You would avoid that by having one radio, and like WiFi or Ethernet between the two computers

That’s what I was worried about.

The goal is to setup a system or multiple nodes with 2 RFD900 every 30km, direct line of sight, connected to a companion computer

The first RFD900 will be in constant communication with her sisters on land, intercepting upstream packets, adding data, then transferring to the next downstream system, which will do the same task, so I could relay telemetry to a far away ground station.

The second RFD900 is a simple link with the drone and with data gathered from other nodes, switch on the TX with a transistor when the RSSI is higher than other nodes, so only one pair is talking at a time.

But it really seems too complex and since I can’t get 3G, 2G or even GSM connection in most of the places, I must switch to Satcom like Iridium or Thuraya on the drone, so I have two choices :

  • Iridium go with unlimited data, Intel stick for Xgate then an API to read iridium mail and act as a server for MP connection, or

  • Direct Thuraya internet connection via UDP or TCP with a bulky phone and a companion computer to send telemetry every 20 seconds

Update 1 : With Thuraya, full telemetry at 1Hz, the cost is 35 euros per flight hour. I will try Monday to cut SRX_RAW SENS, SRX RC CHAN, SRX RAW CTRL, SRX PARAMS and SRX ADSB.

Iridium is not really reliable, it seems like you need a connection to all GCS’s at the same time, can’t you just do a handover ? (disabling the first RFD900 once next takes over ?)

  • you could also , with some software/hardware modification, make only one transmitting, while the other radios would only listen on. (remove the chance for collision.)

Yep, that’s what I was thinking : shared and live database with every nodes Ref and RSSI, use only Tx on the strongest one and switch to the next nodes when the received RSSI is above all other for more the 30 seconds. I even look at the new RFD900x and the Asynchronous non-hopping mesh, it’s really promising :slight_smile:

To get the coverage I need, I would need 50 nodes at first, then, 300 or 600 with backup, massive installation work and thief here, are known to cut and climb 90 kilo-volts power lines, just to steal aluminium cables. Just too risky and complex.

I am just wondering what high-frequency trading, non dark fibers providers are using to get a wireless bandwidth of 10 Gb/s, on a 110km distance. Or maybe I should use ultra low frequency, like submarine coms tech! Just kidding :wink:

I will do some more research, but I am really thinking of ordering a Thuraya XT-PRO with an external antenna. If I can output only essential data, compress it on the go “1/4 size” and then, send it at a slower rate than Mavproxy 1Hz limit, once every 10 seconds, it will cost me less than 0.2 euro per hour

reviving an old thread here

@bendead what did you end up doing? exploring satcom options and wondering if you went that route with success