Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

RC Radio Frequency

Discussion in 'General Discussion' started by Galen Tillery, Jul 26, 2015.

  1. Galen Tillery

    Joined:
    Jul 26, 2015
    Messages:
    10
    Likes Received:
    4
    Hey guys,
    I just joined the quadcopter hobby last week.
    I spent quite a while flying RC helicopters about 7-8 years ago.
    My question relates to RC frequency.
    Are our P3's on a certain RC frequency like RC heli's?
    Is there any opportunity to have such frequencies conflict if I am flying near other P3 pilots?
    Thanks for any help!
     
  2. rockydog

    Joined:
    May 25, 2015
    Messages:
    881
    Likes Received:
    248
    Location:
    London UK
  3. SteveMann

    Joined:
    Aug 27, 2014
    Messages:
    1,977
    Likes Received:
    653
    Location:
    Westford, MA
    The technology in today's RC gear uses frequency hopping or spread spectrum. This is the same method used in cellphones where you can have hundreds of simultaneous users at the same time. I.E., no problem.
     
  4. Galen Tillery

    Joined:
    Jul 26, 2015
    Messages:
    10
    Likes Received:
    4
    Thanks guys for the quick response.
    Makes perfect sense.
    Happy Flying!
     
  5. Edmund Li

    Joined:
    Aug 2, 2015
    Messages:
    3
    Likes Received:
    0
    Hi,

    By any chance do you know what is the communication protocol used between the RC and the drone itself? I'm referring to the control protocol that the RC sends to the drone to tell it where to go.

    Thanks in advance!

    Cheers,
    Edmund
     
  6. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,612
    Location:
    Palm Beach Co.- FL
    DJI calls the protocol DESST. (DJI Enhanced Spread Spectrum Technology)

    It is 100% compatable with Futaba's FASST.
    In fact because the P2 non-visions use 2.4GHz for control you could bind a Futaba FASST radio to the P2's DJI receiver.

    There should be some technical info on FASST 'out there' if look for it. This should shed some light on your question(s).
     
    Falcon900 likes this.
  7. ianwood

    ianwood Taco Wrangler
    Staff Member

    Joined:
    Jan 7, 2014
    Messages:
    4,910
    Likes Received:
    1,789
    Location:
    Lost Angeles
    I believe the OP is asking about the P3 which doesn't use FASST or spread spectrum frequency hopping. The above answers apply to the P2 (non-vision).

    The P3 uses Lightbridge which is based on a proprietary protocol. It changes channels infrequently if at all. It is a bi-directional MIMO OFDM. The video downlink requires a lot of bandwidth in the 2.4GHz ISM band. Two P3s can interfere with each other's video signal. The RC control portion of that is done at a higher priority and is much less likely to be compromised.
     
  8. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,612
    Location:
    Palm Beach Co.- FL

    Ahh yes, LB. True that.

    I lost sight of the P3 reference.
     
  9. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,612
    Location:
    Palm Beach Co.- FL

    Ahh yes, LB. True that.

    I lost sight of the P3 reference.

    I also read somewhere that DJI does not reccommend more than 3 P3s operating at the same time but I cannot locate the doc. or a link.
     
  10. Bryce

    Joined:
    Jun 13, 2015
    Messages:
    445
    Likes Received:
    95

    I would think that's because they are using ISM channels up to 20 and you can only get 3-4 channels in there before they overlap on each other.
     
  11. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,612
    Location:
    Palm Beach Co.- FL
    Good enough.
     
  12. Edmund Li

    Joined:
    Aug 2, 2015
    Messages:
    3
    Likes Received:
    0
    Just for clarification, in the P3, the Lightbridge is used for both control link between the RC & drone, and the video downlink?

    I read the DJI P3 specification on their website, they specified that:
    1. the remote controller uses 2.4 GHz to 2.483 GHz
    2. the video link uses 2.4 GHz ISM

    So the Lightbridge transmit in both the range 2.4-2.483 GHz and 2.4 GHz ISM?

    Wonder if anyone tried to capture some communication between the remote controller and the P3?
     
  13. Youngbill

    Joined:
    Jul 14, 2015
    Messages:
    158
    Likes Received:
    67
    Location:
    PA
    Working on capturing some right now. Much work needed still for this anti-drone device.
     
    Edmund Li likes this.
  14. Edmund Li

    Joined:
    Aug 2, 2015
    Messages:
    3
    Likes Received:
    0
    That's cool!

    What hardware equipment and software are you using to do the capturing? Possible to share?
     
  15. Youngbill

    Joined:
    Jul 14, 2015
    Messages:
    158
    Likes Received:
    67
    Location:
    PA
    It's very cool! Can't share at this point.....sorry.
     
  16. lomax

    Joined:
    Aug 11, 2015
    Messages:
    40
    Likes Received:
    13
    Location:
    Westminster Colorado
    So if you go to a RC airpark what frequency do you tell them you are transmitting on ?

    Marc
     
  17. Youngbill

    Joined:
    Jul 14, 2015
    Messages:
    158
    Likes Received:
    67
    Location:
    PA
  18. ianwood

    ianwood Taco Wrangler
    Staff Member

    Joined:
    Jan 7, 2014
    Messages:
    4,910
    Likes Received:
    1,789
    Location:
    Lost Angeles
    Purposefully interfering with the radio communications of FCC approved devices operating in FCC regulated radio spectrum is against the law. That would include any such anti-drone device.
     
  19. Youngbill

    Joined:
    Jul 14, 2015
    Messages:
    158
    Likes Received:
    67
    Location:
    PA
    The law doesn't apply to some.
     
  20. Daryl

    Joined:
    Aug 24, 2015
    Messages:
    3
    Likes Received:
    0
    I`d recommend you to see this guide [Promotional link removed] .It use Spread Spectrum technology. Phantoms fly on 2.4GHz...
     
    #20 Daryl, Aug 24, 2015
    Last edited by a moderator: Aug 24, 2015