P3S 5.8ghz Controller RF Signal Bi Directional or Not?

[Frank Pliska III]

Does anyone know if the P3S 5.8ghz Controller RF Signal is Bi Directional or Not?
I know the 2.4ghz signal for FPV is bidirectional but always wondered if the 5.8ghz is?
I would like to request a response from a DJI rep or someone equivalent to shed some truth on this subject. Is the 5.8ghz signal on a P3S transmit only from the controller unlike the 2.4ghz signal which is bi-directional??????
PLEASE, NEED TO KNOW FOR SURE. Thanks to all for responding.

 

[805hd]

What do you mean bi directional? Like Omni directional antenna?

 

[WilliamM]

Yes, agree. The control 5.8 stock antenna is omni directional.

 

[805hd]

Yes, agree. The control 5.8 stock antenna is omni directional.

Lol So used to seeing the DBS on there I forgot all about the stock setup!

 

[OrlyP]

Bi-directional in the OP's context is in terms of communications. In other words, we're all 100% sure that the controller transmits stick commands using 5.8GHz. But the question is, does the aircraft provide any feedback communications on 5.8GHz? Or all that is done over 2.4GHz, along with the video feed and probably some other stuff?

My personal opinion is that, 5.8GHz is TX only. Telemetry information and video is received via 2.4GHz. Missions are also probably sent over 2.4GHz.

The 2.4GHz communications used on the P3S is standard 802.11 WiFi.... which is a bi-directional (half-duplex) wireless protocol.

 

[SkyHog]

Bi-directional in the OP's context is in terms of communications. In other words, we're all 100% sure that the controller transmits stick commands using 5.8GHz. But the question is, does the aircraft provide any feedback communications on 5.8GHz? Or all that is done over 2.4GHz, along with the video feed and probably some other stuff?
My personal opinion is that, 5.8GHz is TX only. Telemetry information and video is received via 2.4GHz. Missions are also probably sent over 2.4GHz. The 2.4GHz communications used on the P3S is standard 802.11 WiFi.... which is a bi-directional (half-duplex) wireless protocol.

I agree. If the 5.8 GHz link was bi-directional, there would be no need to push miscellaneous status and other technical data back to the controller via the video link. At the same time, there is no need to make the control link bi-directional, when the bi-directional video link already exists on the bird. So the logical conclusion is that the 5.8 GHz link protocol is probably a very simple send-and-pray one-way link without any message acknowledgement whatsoever, though I have never seen any tech documentation from DJI to confirm this.

 

[frenky600]

I agree. If the 5.8 GHz link was bi-directional, there would be no need to push miscellaneous status and other technical data back to the controller via the video link. At the same time, there is no need to make the control link bi-directional, when the bi-directional video link already exists on the bird. So the logical conclusion is that the 5.8 GHz link protocol is probably a very simple send-and-pray one-way link without any message acknowledgement whatsoever, though I have never seen any tech documentation from DJI to confirm this.

Mumble mumble....i'm confused. One month ago i take a field misure on 5.8 dipole on bird. I found 17dbm on one antenna and 2 dbm on second. My drone in stock config take 40mt distance.

 

[OrlyP]

Mumble mumble....i'm confused. One month ago i take a field misure on 5.8 dipole on bird. I found 17dbm on one antenna and 2 dbm on second. My drone in stock config take 40mt distance.

Well I concede then. Without the proper equipment (RF analyzer and protocol analyzer) or access to detailed specs of the P3S, the best anyone can do is speculate.

 

[frenky600]

Well I concede then. Without the proper equipment (RF analyzer and protocol analyzer) or access to detailed specs of the P3S, the best anyone can do is speculate.

This however is an interesting topic especially for all those who like me have rc signal problems. Know if the drone transmits or not ...... can also help figure out if updates have fried a part of motherboard.

 

[solentlife]

5.8Ghz is only single direction from Controller to Aircraft.

2.4Ghz is bi-directional to provide Video and Telemetry flow.

Nigel

 

[Frank Pliska III]

Unidirectional I thought so. I just needed some confirmation. I am building a 5.8ghz RF amplifier. I would like even better range than my antenna mods just to have a better piece of mind to bring the AC back with manual RTH if needed. P3S

 

[OrlyP]

5.8Ghz is only single direction from Controller to Aircraft.

2.4Ghz is bi-directional to provide Video and Telemetry flow.

Nigel

This was also my belief. But then, assuming that Frenky600 above did his testing properly, how does one explain the aircraft transmitting 'something' on 5.8GHz?

 

[SkyHog]

This was also my belief. But then, assuming that Frenky600 above did his testing properly, how does one explain the aircraft transmitting 'something' on 5.8GHz?

Yes, I've got nothing but speculation myself. But the real proof is a good test. I would agree that trumps all speculation.

 

[solentlife]

Ask any radio guy about RF and he will tel you that stray output can be found of literally any frequency in low levels.

Not only that but also harmonicsc ....

Nigel

 

[OrlyP]

Ask any radio guy about RF and he will tel you that stray output can be found of literally any frequency in low levels.

Not only that but also harmonicsc ....

Nigel

Again, working on the assumption that he knew what he was doing, he was very specific about the measurements coming out of both 5.8GHz antennas. In the electronics world, 17dBm (50mW) is one heck of a stray RF.

 

[Frank Pliska III]

When you say BOTH 5.8ghz antennas are you referring to the AC & the Controller?
I would like to request a response from a DJI rep or someone equivalent to shed some truth on this subject. Is the 5.8ghz signal on a P3S transmit only from the controller unlike the 2.4ghz signal which is bi-directional??????
PLEASE, NEED TO KNOW FOR SURE. Thanks to all for responding.

 

[solentlife]

Again, working on the assumption that he knew what he was doing, he was very specific about the measurements coming out of both 5.8GHz antennas. In the electronics world, 17dBm (50mW) is one heck of a stray RF.

Sorry I only read it quickly and now I see he is referring to both antenna on the bird ... I assumed one was Controller and other bird.

Nigel

 

[solentlife]

When you say BOTH 5.8ghz antennas are you referring to the AC & the Controller?
I would like to request a response from a DJI rep or someone equivalent to shed some truth on this subject. Is the 5.8ghz signal on a P3S transmit only from the controller unlike the 2.4ghz signal which is bi-directional??????
PLEASE, NEED TO KNOW FOR SURE. Thanks to all for responding.

Don't hold your breath waiting for DJI to answer !! Even when they do - the answer changes depending who answers ... I gave up with them ages ago when I had so many conflicting replies from them.

Nigel

 

[WilliamM]

Don't hold your breath waiting for DJI to answer !! Even when they do - the answer changes depending who answers ... I gave up with them ages ago when I had so many conflicting replies from them.

Nigel

Agree with that, I got the impression that the Reps on the official DJI site are just like the customer service people of companies here, just hourly employees with basic training to answer the phone.

 

[Frank Pliska III]

I would think my question has only a single answer, YES or NO with no conjecture...........