Interference question from newbie

[CFI]

I'm betting this has been discussed but I can't find where. I was wondering if more than one drone flying in a given area can interfere with each other ? Do drones have discrete frequencies dynamically allocated? Can someone with a similar controller take over my drone? Is it like using wifi at Starbucks or something more sophisticated? .....Just wondering because I'd like to fly my Air2s in some busy cities. Any info is appreciated. Thanks!

 

[sar104]

To control an aircraft the RC has to be paired with it. So no - that cannot happen. And multiple RC-aircraft can coexist just like multiple discrete wifi networks.

 

[SethB]

Yesterday we were flying three Mavic 2 very close. The only interference problem we had was with buried lawn sprinkler pipes.

 

[CFI]

To control an aircraft the RC has to be paired with it. So no - that cannot happen. And multiple RC-aircraft can coexist just like multiple discrete wifi networks.

Interesting. So when an aircraft is paired to an RC the generated frequency or frequencies used are totally unique in each use?

 

[CFI]

Yesterday we were flying three Mavic 2 very close. The only interference problem we had was with buried lawn sprinkler pipes.

The sprinkler pipes caused problems? What kind?

 

[sar104]

Interesting. So when an aircraft is paired to an RC the generated frequency or frequencies used are totally unique in each use?

No - it's 2.4 and 5 GHz spread spectrum. Nothing at all unique about the frequencies.

 

[Meta4]

I was wondering if more than one drone flying in a given area can interfere with each other ?

You can get minor interference between controllers if they are too close.
But just move a few metres apart and that disappears.

 

[CFI]

You can get minor interference between controllers if they are too close.
But just move a few metres apart and that disappears.

Thanks! What do you mean by "minor" interference?

 

[CFI]

No - it's 2.4 and 5 GHz spread spectrum. Nothing at all unique about the frequencies.

Thanks, that makes me feel more comfortable. Wasn't spread spectrum developed by the military to evade jamming??

 

[SethB]

The sprinkler pipes caused problems? What kind?

It’s hard to be sure, but I think we’ve got buried metal pipe in one of our flying areas. We’re adjusting our launch/landing positions based on some visible substantial valve or junction boxes. Moving a few feet seems to quiet the interference warnings.

 

[Meta4]

Thanks! What do you mean by "minor" interference?

Very minor glitches in video and control, that will disappear if you just move a few metres further apart.

 

[RadioFlyerMan]

I'm betting this has been discussed but I can't find where. I was wondering if more than one drone flying in a given area can interfere with each other ? Do drones have discrete frequencies dynamically allocated? Can someone with a similar controller take over my drone? Is it like using wifi at Starbucks or something more sophisticated? .....Just wondering because I'd like to fly my Air2s in some busy cities. Any info is appreciated. Thanks!

Here’s an example of both transmitters in close proximity, and the aircraft in close proximity. No issues at all.

 

[CFI]

Here’s an example of both transmitters in close proximity, and the aircraft in close proximity. No issues at all.

Thank you. That helps reassure me -- especially after my recent mishap with an Air 2 (now resting peacefully in the trees at the top of a mountain ) ;-)

 

[fRog2]

It is just like wifi to all intents and purposes and as the controller and aircraft communicate many times a second, it doesn't matter if some of the signal is lost.

Short of hacking, the aircraft will only ever respond to the controller it is bound to. The same technology is used by model aircraft and boats and is never an issue even at large meetings.

 

[CFI]

It is just like wifi to all intents and purposes and as the controller and aircraft communicate many times a second, it doesn't matter if some of the signal is lost.

Short of hacking, the aircraft will only ever respond to the controller it is bound to. The same technology is used by model aircraft and boats and is never an issue even at large meetings.

That is great to know ! Thank you

 

[Ronson]

Someone with greater knowledge than me may contradict.

Pairing means they recognize each other’s messages. Another devices message may be received but recognized as not for me, not my paired device. The probably exchange device id’s as a key. They all monitor the same band looking for the paired device key.

 

[Ralph thompson]

It’s hard to be sure, but I think we’ve got buried metal pipe in one of our flying areas. We’re adjusting our launch/landing positions based on some visible substantial valve or junction boxes. Moving a few feet seems to quiet the interference warnings.

Seth, I think u may be mixing up magnetic interference and radio interference. The warning yr getting is telling you the compass is being offset by a nearby metal object which could be the pipes. This would lead to a compass error and moving away a 20 or 30 ft would probably solve the proble.

 

[Dave Maine]

The DJI drones all use the standard WIFI frequencies. They use different signaling protocols (Occusync etc) to harden the specific data exchange path. In addition, each path is paired between the controller and drone uniquely so that other signals on the same frequency are ignored.

 

[CFI]

It is just like wifi to all intents and purposes and as the controller and aircraft communicate many times a second, it doesn't matter if some of the signal is lost.

Short of hacking, the aircraft will only ever respond to the controller it is bound to. The same technology is used by model aircraft and boats and is never an issue even at large meetings.

Interesting....You'd think that some kind of harmonics would occur and interfere with multiple craft using the same relative bandwidth. Thanks!

 

[sar104]

Interesting....You'd think that some kind of harmonics would occur and interfere with multiple craft using the same relative bandwidth. Thanks!

I think you have misunderstood the physics of harmonics. Time to break out a textbook or head over to Wikipedia.