Internet speed minimum requirement

General Discussion
1

Hi,

I was wondering what is the minimum recommended download and upload speed to control the rov over 4g/5g with zerotier without any problems?

Cheers

2

Hi @Jhans,

I don’t believe we have any specific recommendations on this, but just thinking through it conceptually:

  1. the vehicle sends much more data (telemetry, video stream(s), sonar profiles, etc) than it receives (motion and sensor control commands), so the required speeds are highly asymmetrical
    • from a quick Wireshark test, my system with a single Blue Robotics Low-Light HD USB camera (running at 1080p30) and an ethernet-connected Ping360 was
      • sending ~15 Mbps (vehicle upload, topside download), and
      • receiving ~500 kbps (vehicle download, topside upload)
    • higher bandwidth capacities can be useful, but aren’t critical - vehicle upload speeds above what’s required for real-time control will mostly help to reduce the initial loading time of web interface elements, especially on computers that have not recently accessed the web interface
  2. minimum data rates are important, but for responsive manual control you’ll also need consistently low latency
    • as I understand it ~100 ms is around the point where things start to feel laggy, but higher values can be manageable if your application allows slow changes rather than requiring fast-paced manoeuvres and adjustments
    • ZeroTier and other network redirections and conversions add to latency
  3. latency jitter and dropped packets (from obstructions and network issues and the like) can also contribute to a connection feeling poor / laggy, and may result in skipped video frames or visual artifacts
3

I see, is there any particular tips you have to get the best experience and as low latency as possible when running over zerotier?

4

This isn’t something I’ve dug into or tried to test, so my only tips are to read the ZeroTier configuration documentation if it’s something you want to play around with.

I would recommend setting up and testing a network normally first, and only trying to change configuration options if you decide that standard performance is unacceptable, and have determined that it’s the ZeroTier part that’s the problem (rather than the other network hardware and configurations throughout your system).

5

Hi Jørgen -

I’ve used an ROV remotely over a very long range wifi connection with limited bandwidth. We found setting the video stream to 720p, 10-15 fps, and adding mtu=1300 to the video pipeline can result in usable control, but as Eliot mentioned video is main bandwidth consumer. I saw 5-8mbps sent from vehicle, with ~500kbps sent to it.

If just driving a vehicle, like say a Blue Boat, over 4g, with no video stream present, the connection and usability is much improved.

Eager to hear if you have success with ROV over 4G!

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