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Why use 5.8Ghz t/x

Discussion in 'Phantom 2 Vision Discussion' started by Funnone, Jan 29, 2014.

  1. Funnone

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    Hey guys quick question, I just purchased the DJI phantom 2 vision.why do they use 5.8 Ghz for the t/x and r/x if it has less range and its more directional why don't they use something on the lower bandwidth (2.4) Cost? 10 years ago I used to fly third scale gas airplanes so I'm kind of out of the loop with this new stuff. Thanks for any help...
     
  2. themosttoys

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    I'm sure there were many reasons they chose 5.8ghz. The main reason that 2.4ghz was not an option (today's defacto standard for tx/rx) was that they are using wifi (2.4ghz) to your phone for the FPV, telemetry,... I read somewhere that at one point they considered using the phone wifi for all controls (ala ARDrone) but thankfully decided against that.
     
  3. jimre

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    It's because Wi-Fi-enabled smartphones are such a key part of the Vision product - and they run on 2.4 Ghz. Having the flight-control system also running on the same frequencies in close proximity would cause significant interference. Therefore the flight-control system runs on 5.8 Ghz.

    Most existing RC models work the opposite. Flight-control is on 2.4 Ghz, and video - if any - is on a 5.8 Ghz system. But then you're screwed if you want to directly use your smarphone's built-in Wi-Fi for video.
     
  4. BenDronePilot

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    Not entirely true, many newer smart phones and tablets support 5.8ghz wifi. Though from the perspective of having the widest level of compatibility with older devices it makes sense to use 2.4 ghz wifi. It may also have been more cost effective utilizing a 2.4ghz wifi in the camera vs a 5ghz system. Also a 5.8ghz wifi connection to the phone would have given reduced range though more reliable at shorter distances. The higher output of the 5.8 ghz transmitter ensures that even with a modded Phantom 2 Visions wifi, the weakest link is usually the FPV before the Transmitter unless you're pushing mile and a half distances through your FPV. Also, 5.8ghz is less susceptible to interference than 2.4ghz so that may also be consideration. What's more important, reliable video feed vs reliable control feed? Assuming you're always flying within Visual Line of Sight. I'm sure the 5.8ghz control feed also helps reduce the risk of interference related fly aways as 2.4ghz signals are all over the place far more so than 5.8ghz transmissions. Those are all possible reasons, though if I was a betting man I'd go with the first reason as being most likely. A future Phantom Vision and or upgrade should provide the option of a dual band wifi and transmitter switchable so we can use either 2.4 or 5.8ghz. The addition of a high speed wireless N or AC standard would also be nice for improved quality. As it stands the connection speed is around 54mbps which is Wirless G technology speeds.
     
  5. jimre

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    I agree, but only iPhone 5 and above support 5.8Ghz - greatly limiting who could use the product. I'm sure it would likewise limit which Android phones you could use. And as you point out, it may have been cost-prohibitive to find 5.8 Ghz Wi-Fi parts suitable to fit their design (and budget) for the camera and w-fi repeater.