Telemetry/Video over 4G/LTE Cellular link for Beyond-LOS Flight

I have a thought to use cellular technology to pipe video and data over a UDP connection.  This is nothing, however, I haven't seen a lot of support for the usage of 4G/LTE which allows up to 100mbps speeds.  Has anyone ever read up on this pico board?  I'ts available from min-box.com.  The same place I received my mini-PC for my GCS.

I had this idea about hosting a UDP server on board the aircraft with this pico board.  Then routing all traffic through a VPN tunnel where it will be connected to the GCS via internet/VPN tunneling.

The APM will connect to the board via serial I/O.  The tricky part (for me) will be routing that serial traffic over a UDP connection.  Any idea a simple(r) way to do this with Linux instead of any software-based routing procedures?  I very familiar with Linux, just haven't done any network routing inside a client-only environment.

Any thoughts or concerns are more than welcome!

Views: 7144

Comment by Hunter Parris on April 16, 2013 at 8:56pm

Instead of using Angstrom, this board also supports Android.  Which would be better for doing this?  I'm not TOO familiar with Android, but I always love learning it!

Comment by Tobias Krieger on April 17, 2013 at 12:41am

I guess you don't want to use gstreamer?

#!/usr/bin/perl

use strict
;
use warnings
;

use
Device::SerialPort;

my $port1_path
= '/dev/tty1';
my $port2_path
= '/dev/tty2';

my $port1
= Device::SerialPort->new($port1_path);
$port1
->databits(8);
$port1
->baudrate(19200);
$port1
->parity("none");
$port1
->stopbits(1);

my $port2
= Device::SerialPort->new($port2_path);
$port2
->databits(8);
$port2
->baudrate(19200);
$port2
->parity("none");
$port2
->stopbits(1);

while ($in = $port1->input) {
    $port2
->write($in);
}

 Must be adjusted to you port config.

Comment by Luke Olson on April 17, 2013 at 3:11am

I wouldn't trust cellular networks for FPV, especially beyond line of sight. The latency would be inconsistent and there's a pretty good chance of completely losing the signal at least once during a flight (at least where I live!).

Comment by Tommy Larsen on April 17, 2013 at 3:12am

This should work, just adjust it to your serial port setting :

sudo apt-get install ser2net

sudo nano /etc/ser2net.conf

% change last lines to
2000:telnet:600:/dev/ttyAMA0:57600 8DATABITS NONE
1STOPBIT banner

sudo /etc/init.d/ser2net restart

sudo nano /etc/inittab
% add hash to this line
#T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100

sudo nano /boot/cmdline.txt
% delete references to ttyAMA0
% "console=ttyAMA0,115200 kgdboc=ttyAMA0,115200"

Comment by Tommy Larsen on April 17, 2013 at 3:13am

BTW: I'm already running my aircraft via 3g. Both video and telemetry.

Comment by Luke Olson on April 17, 2013 at 3:15am

Do you experience any connection issues? If so how do you handle them? Thanks for posting the configurations.

Comment by Bryan Galusha on April 17, 2013 at 6:28am

We are crowdfunding something very similar.  We are using the Z3-DM368-MOD board from a small american company Z3 Technologies in Lincoln, NE.  

You can see the specs on the related devboard here:
http://z3technology.com/wp-content/uploads/2013/01/Z3-DM368-VI-RPS.pdf

In development the main issue we have found when developing with the Gumstix FireStorm is latency and framerate.  We could only get 5fps with the gumstix and the latency was 2 seconds which is standard for a highly compressed H.264 stream.  Z3's latency is wonderfully low at at 48ms and we have seen in the field going from one Verizon LTE device to another Verizon LTE device (basically bouncing off the tower) latencies as low as 22ms.  The key is never going out to the internet, but staying inside Verizon's (or other carriers) network.  Which is pretty simple with Verizon since they assign LAN IPv4 ip addresses (192.168 for example) you can use to ensure you don't leave the Verizon network.  With these two techniques we can make FPV possible although there is still some risk of losing the cell signal on a long flight.

The key is Z3's module uses TI's DM368 processor which is an ASIC dedicated for high performance video encoding/decoding traditionally used for the surveillance camera market.

Although Z3's module will be closed source all the HW, SW, and Mechanical we develop will be open source.  Z3's module is really just a processor, so it is similar to not having the Verilog of the ARM chip on the PX4.

You can check us out here:
www.fightingwalrus.com

We just launched our RTF airframe with the 4G or WiFi video capability and it is in "soft launch" mode right now with minimal details for friends and family.  Full PR to come shortly.


Developer
Comment by Kevin Hester on April 17, 2013 at 6:53am

I've had preliminary success putting an android phone into a plane and using that for control (others have as well).  I'll post some details eventually.

Comment by c j g on April 17, 2013 at 10:47am


I 've tested some possibilities with an android 3G smartphone for telemetry and video [ for FPV the latency isn't really the best ;) ]. But there are some other little limitations,
link: Telemetry over 3G / Video over 3G ( IP / TCP ) with android

best .cj

Comment by SaadT on April 17, 2013 at 11:03am

Bryan,

Interesting stuff about the DM368. I have been looking at the Z3 module you mentioned as well. Unfortunately its a little expensive for me to buy, at the moment..so will have so save some more. Can you tell me if you built a daughter board to interface the module to a camera? What camera are you using and what's the interface between the camera and the Z3 module?

Also, an odd question..how easy or difficult is it to work with video encoding/decoding with the DM368? :)

Regards,
Saad

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