Max sustained Radiolink bandwidth SURVEY with iOS DJI App

[Solar]

Hi Guys!

This is a survey for Phantom 3 Professional users and not the Advanced users or P4 users. It will take 10 minutes of your time, but may result in DJI do something about the problem we seem to have. Roll-in guys!

We all know that there is an option to download videos from your drone to iPad wirelessly over the aircraft-RC radio link. There is a small "download" button in the right-bottom corner of the video manager window which appears if you press "video" button (the rightmost if you face the RC usually with controls in your front).

Please try to download file large enough to let the download speed become sustained (not jumping) and report the number in Kb/sec. Also, please append to your report the following details:

- your DJI Go version.
- channel used (number set in Manual, or auto)
- bandwidth selection (if Manual) from 4,6,8 or 10 Mb/sec.
- your RC firmware version (1.6, 1.8, 1.9)
- your drone firmware version (you can quickly read this in DJI Go app "about" screen)

and the result:

- download speed is maxed, sustained at (number)
- download speed is more or less close to expected with minor jumps (average)
- download speed is not stable, jumping in the whole range (most frequent values range)
- download speed is diffult to see, massive jumping, sometimes disconnecting/reconnecting (drone will momentarily flash red)

Why this survey?

I noticed that when I set HD link to "manual", and pick up any free channel,
and set the bandwidth to max value (10 Mbits) or even close to that (8 Mbits) I no longer can get max sustained speed. It used to be up to 1140 KB/sec a year ago, with the same settings. Which more or less fits the 10 Mbits setting.

Now, I get constant jumping from 20 KB/sec to 1140 KB/sec with major percent of values in 200-500 KB/sec range. Overall average is considerably lower than max 1140 sustained speed I had before!

Now, I can only get sustained download speed at 6 Mbit bandwidth which is about 650 KB/sec.

There are several explanations to this. Either my transmitter/received is detuned and malfunctioning and cannot sustain higher bandidth stable transmission,

OR

We guys have a problem here with radio link quality, which can be demonstrated to DJI Support with numbers in hands.

But you know guys DJI will do nothing from a single report.
We have to do it together guys, I count for your help!

My entry:

- DJI Go 3.1.15
- channel 13-19, manual
- bandwidth 8 or 10
- RC firmware: 1.8.0
- AC firmware: 1.9.60
- Result: download speed jumps in range 20 KB/sec to max, averaging in 400-500

Thank you everybody!

P.S.:

Big "B" for Byte,
Small "b" for bit
"M" for Mega = 1048576 multiplier.
"K" for Kilo = 1024 multiplier

1 KB = 1 KByte
1MB = 1MByte = 1024 KBytes = 1048576 Bytes

In the DJI Go download message box, momentarily speed is given in KB.

While in the bandwidth settings, it is given in Mbits. Traditionally.

So, 1140 KB per second = 9120 Mbits bandwidth.
and 625 KB per second = 5000 Mbits bandwidh.

 

[Philltayl]

This is also device dependent and that is a hugh factor in the sustained datalink speed but you appear to have ignored that fact......

 

[Solar]

Agree. Let's add "device" data field to the Survey.

Mine is iPad Air 2.

However, at such the data rates (1 MByte/s max), I bet nearly no device will be loaded high enough to be a limiting factor... ten years ago, maybe some of them would fail )

 

[crash1sttime]

Why just the pro, the advanced is the same as the pro except for the camera

 

[Solar]

Why just the pro, the advanced is the same as the pro except for the camera

Please, do not jump off the topic. Keep compact, this is a survey thread, not a discussion.

It was discussed a million times elsewhere, why. Because Advanced can only max at 6 Mbps, it is the point where there is no difference, but camera. And the problem we have with Professional is that it can sustain 8 and 10 Mbits/sec no more. Possibly, due a software bug in DGI Go. Or, the encoder chip is dead, rendering the Pro with its camera to become effectively Advanced.

 

[Oso]

It was discussed a million times elsewhere, why. Because Advanced can only max at 6 Mbps, it is the point where there is no difference, but camera. And the problem we have with Professional is that it can sustain 8 and 10 Mbits/sec no more. Possibly, due a software bug in DGI Go. Or, the encoder chip is dead, rendering the Pro with its camera to become effectively Advanced.

Just a quick correction in case someone who isn't aware reads this thread. The P3A will not go up to 6Mbps regardless of the manual setting. It has a ~2Mbps max downlink per spec. The P3P does have a max of 10Mbps per spec as correctly noted, and it can be adjusted manually in the settings. This to me is one of the most significant differences between the two models.

It used to be up to 1140 Kb/sec a year ago, with the same settings. Which more or less fits the 10 Mbits setting.

You noted that 1140Kbs is "more or less" the same as 10Mbps, when in fact 1140Kbs equals 1.14Mbs. That's much less than 10Mbs.
Did you perhaps inadvertently confuse a "B" with a "b" in your posts, or has your P3P always had a much lower downlink speed than spec?

UPDATE: Thanks for correcting your original post to now show the correct bandwidth speeds.

 

[Solar]

Just a quick correction in case someone who isn't aware reads this thread. The P3A will not go up to 6Mbps regardless of the manual setting. It has a ~2Mbps max downlink per spec. The P3P does have a max of 10Mbps per spec as correctly noted, and it can be adjusted manually in the settings. This to me is one of the most significant differences between the two models.

Just a quick correction in case someone who isn't aware, reads this thread))

The quoted opinion is only opinion backed by some contraversary data. In reality, Advanced download maxes at 640-700 KBytes per second which gives 8bits per byte = close to 6 Mbits per second. Bits are not bytes. Refer to Wiki.

Hence,

You noted that 1140Kbs is "more or less" the same as 10Mbps, when in fact 1140Kbs equals 1.14Mbs. That's much less than 10Mbs.
Did you perhaps inadvertently confuse a "B" with a "b" in your posts, or has your P3P always had a much lower downlink speed than spec?

1140 Kbytes per second means 8 times more divided by 1024 (number of KBytes in one Megabyte), thus it equals to roughly 10 Mbits per second.

In fact, the link speed is always slightly less, because of packaging, correction and protocol bits.

Bottom line: Read carefully. Think intellingly. Answer responsibly.

Any measured data, guys?

I don't want discussions here, I need data.

 

[Philltayl]

1140 Kbytes per second means 8 times more divided by 1024 (number of Kbytes in Megabyte), thus it equals to roughly 10 Mbits per second.

In fact, the link speed is always slightly less, because of packaging, correction and protocol bits.

Bottom line: Read carefully. Think intellingly. Answer responsibly.

Any measured data, guys?

I don't want discussions here, I need data.

Why cause confusion with bits and bytes here. The defacto standard is to use Bits per Second

 

[Solar]

Why cause confusion with bits and bytes here. The defacto standard is to use Bits per Second

Sorry. I will correct "Kbytes" into "KBytes" as it should be. Mislooked text autocorrection.

Why?

Because it is given so in the DJI GO app. In the download message box, they are presented as "KiloBytes" while in the Bandwidth setting window, they are given as "Mbits".

Update. Corrected.