Lightbridge vs WIFI for control

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Hi,

So I'm ready to take the plunge and purchase a phantom 3 but haven't been able to figure out one thing:

I know that lightbridge on the P3A allows great video for FPV over a much longer distance compared to the P3S's wifi, but is this only for downlink video? What about the RC controller end?

forgetting the video - can the P3A be controlled farther compared to a P3S or is the RC link really the same between the two? Is lightbridge also used to CONTROL the drone or just for the video end? If not, I would assume they would be similar control range in a dense urban environment.

Thoughts?
 

Meta4

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I know that lightbridge on the P3A allows great video for FPV over a much longer distance compared to the P3S's wifi, but is this only for downlink video? What about the RC controller end?
Lightbridge handles both video and control signals.
Anyone that's flown wifi drones and Lightbridge knows that Lightbridge is about 10 times better than wifi for video and control and distance.
It's night and day, no contest.
 
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I only own a p3s but as far as I know the control is also sent with lightbridge. The effective control range is greatly increased. And will fly much farther than the wifi. I would probably go for lightbridge if you want distance and have the money. I'm personally happy with my p3s.


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ryantrax

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From DJI's site:

Phantom 3 Advanced:
RC Max Transmission Distance Up to 5 km or 3.1 miles (unobstructed, free of interference) when FCC compliant
Up to 3.5 km or 2.1 miles (unobstructed, free of interference) when CE compliant

Phantom 3 Standard:

RC Max Transmission Distance FCC: 1000 m; CE: 500 m (outdoors and unobstructed, aircraft's altitude at 400 feet (120 m))

I have the P3A and love the Light Bridge, worth the extra $$ IMHO.
 
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so the P3S DOES use lightbridge for the control channel?

In that case the actual flying range should be identical to the P3A (just won't get the video downlink that far since video is wifi only on the P3S)?
According to the phantom website, the control range is much less for the P3S - as ryantrax mentions above as well.

so the question is who is right? I'm assuming their website is correct and there is no lightbridge control channel for the P3S



I only own a p3s but as far as I know the control is also sent with lightbridge. The effective control range is greatly increased. And will fly much farther than the wifi. I would probably go for lightbridge if you want distance and have the money. I'm personally happy with my p3s.


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Meta4

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so the P3S DOES use lightbridge for the control channel?
so the question is who is right? I'm assuming their website is correct and there is no lightbridge control channel for the P3S
That's correct ... there is no Lightbridge in the Standard.
The only Phantoms using Lightbridge are the P3 Adv & Pro and the P4.
 
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so the P3S DOES use lightbridge for the control channel?
No. The Standard uses WIFI, while the Advanced and Pro use Lightbridge.
 
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i had the p3s and now i have the p3a .... the difference its huge, 600m whit the standard and a lot of video and transmission lost .. vs 4km whit the advanced, whit the video and control channel whit no lost of signal at all... the extra money for the advanced worth every penny
 
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i had the p3s and now i have the p3a .... the difference its huge, 600m whit the standard and a lot of video and transmission lost .. vs 4km whit the advanced, whit the video and control channel whit no lost of signal at all... the extra money for the advanced worth every penny
I agree and similarly, also had the P3S, sold it, now the P3A. P3A is what I wanted all along. I outgrew the range on the P3S after, well, the first flight.
 
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I have a problem with my Phantom 3 Pro the signal is very poor after 1 mile starts with video cuts, I had another Phantom 3 advance and 2 miles worked perfectly only one time with a new version de DJI Go was reduces to less than 1 mile. But now I cant found a solution, some ideas???
 
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I have a problem with my Phantom 3 Pro the signal is very poor after 1 mile starts with video cuts, I had another Phantom 3 advance and 2 miles worked perfectly only one time with a new version de DJI Go was reduces to less than 1 mile. But now I cant found a solution, some ideas???
Yep, use the search function magnifying glass in the top right corner and find the many, many posts on this subject. There are some many factors that can kill distance at a location on one day and not, at the same location, on another.
 
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I have a problem with my Phantom 3 Pro the signal is very poor after 1 mile starts with video cuts, I had another Phantom 3 advance and 2 miles worked perfectly only one time with a new version de DJI Go was reduces to less than 1 mile. But now I cant found a solution, some ideas???
Click the HD icon. Choose a custom channel that's quiet, typically ch1 or 20. When you choose custom, then the Transmission Quality option appears. Move the slider bar from 10mbps to 4mbps. Put a Windsurfer on your antennas and enjoy 2 to 3 miles range with LOS connections. The P3A only supports 2mbps so the distance will be good, because it has to do less work to received and display the video. However the iPad clarity during flight will be slightly less on the P3A versus the P3P. If you're flying nearby, selecting 10mbps will increase clarity on the iPad even more, but decrease range.

If you can load the 32ch hack into your Go app, then fly channel 30, you'll never get any interference because it's outside the wifi bands. However, still leave the craft on 4mbps.
 
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Thanks for your answers,
I give you more details, I tried to repeat in different days, about 18 times the test flying always in the same place and the results are practically identical, so I am almost sure that the conditions can affect but.....
I will test the channel 30. With the Advance I flew with normal wifi channels, could be the 2 mbps makes the difference, but I never hear that the Phantom Adv has more range than the Pro. Do you?
I spent some time flying during the lastt 3 years and I love the Phantom 3 but nothing explain this behavior,I read many things about this situation, but finally I have only suspicious.
1º DJI change the firmware to reduce power?
2º New Hardware. The newest Phantom has less power?, realy my new PP has a OFDM module that is a different version.
3º I have a Phantom with something a little bit wrong (hardware)?.
4º I am living in Europe, maybe the Adv was CC configurated and the new CE?
 
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Thanks for your answers,
I give you more details, I tried to repeat in different days, about 18 times the test flying always in the same place and the results are practically identical, so I am almost sure that the conditions can affect but.....
I will test the channel 30. With the Advance I flew with normal wifi channels, could be the 2 mbps makes the difference, but I never hear that the Phantom Adv has more range than the Pro. Do you?
I spent some time flying during the lastt 3 years and I love the Phantom 3 but nothing explain this behavior,I read many things about this situation, but finally I have only suspicious.
1º DJI change the firmware to reduce power?
2º New Hardware. The newest Phantom has less power?, realy my new PP has a OFDM module that is a different version.
3º I have a Phantom with something a little bit wrong (hardware)?.
4º I am living in Europe, maybe the Adv was CC configurated and the new CE?
If you have a new P3P with a GL300C RC, that could be your issue. Your P3A may have the GL300A or B, which could have more transmit power. If you have your P3A still, try linking that RC with the P3P craft and see if that makes a difference. In general, if you have the P3P set to 4mbps with a GL300A or B controller, it will have the same range as your P3A.

I went through similar disappointment when I bought a P4 last year, it was very frustrating.

I did some testing last year and found the GL300C controller to be WEAKER than GL300A and Inspire GL658A. This is exactly why I retired my GL300C and fly my P4 exclusively with a GL658A controller, because it demonstrated more transmit power to control the craft at greater range. I was very unhappy with my P4/GL300C having less than 1mil range, when my P3P easily has over 2mi range in the same test location. I knew there was a reason, and I found it to be the GL300C is anemic for transmit power, 50% less than Inspire GL658A. With GL658A my P4 easily goes 3mi in my normal test area in the hills, 3X what the GL300C could do.

The fact you live in Europe is another issue, even weaker transmit power. I feel sorry for you guys on the other side of the pond, that's really sad. You could use an external amplifier to boost your signal, but that requires another battery you need to charge, not to mention the added bulk and weight to the RC.
 
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Many thanks John,
It is a very interesting work. For me DJI has open the secret to modify the firmware to Phantom 4, spark and Mavic, but nothing about Phantom 3 Adv/Pro, it is clear that this information is not usefull for DJI´s bussines. Anybody Know somthing in order to modify CE-> FCC in the Phantom 3 Adv/Pro?.
 
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So what makes the light bridge so much better? Is it just flat out more power or a different frequency? or something else? Thanks for your thoughts....
 

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A lot of this is theory because there is no blueprint available to the public that illustrates exactly how lightbridge works, so we have to make educated guesses as we use the system and gain experience.

I think one of the things that makes it better is it overcomes some of the inadequacies of wifi, one of which is the "check" which takes place with the wifi protocol. This removes the need for the signal to be two-way and provides the opportunity for better distance, better quality, or both. It's pretty friggin' brilliant. It's scary brilliant.
 
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Wow, I had no idea it was such a big deal! I can tell you from using it, it's awesome compared to other drones, so I knew something was VERY different for the better but I've just been trying to figure out how to explain it to someone shopping for a drone. I'm going to be a DJI rep in a retail store over the Christmas season. Thank You
 
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So what makes the light bridge so much better? Is it just flat out more power or a different frequency? or something else? Thanks for your thoughts....
Lightbridge is a highly sophisticated communications protocol that WAS DESIGNED specifically for video transmission from air to ground. In general terms there are two paths for data, both operate in one direction for simplicity, speed and distance. Control signal goes up (left ant) and video coming down (right ant). There is no handshaking in this protocol, the signal is broadcast and hopefully it gets to it's destination, kinda like a TV video signal from the top of a hill, a one way broadcast. All other drone manufacturers use Wifi, designed for computers, and financial usage. Wifi was not designed for video transmission, but it's cheaper to implement because of the IC's available for the computer market. Wifi has an inherent bottleneck for video transmission, it's called TCP/IP, which is a two way handshake protocol that insures that data gets to it's destination intact and complete, which isn't important for video from drones to ground. That's why wifi is so finicky for drone usage, in comparison to Lightbridge. The linkup time, relink time, distance and reliability of Wifi is inferior to the performance of Lightbridge due to the simplicity (one way comm, no handshakes) and the sophistication of the wireless RF carrier it uses. No other drone manufacturer can compare IMO. Keep in mind that DJI is bound by the FCC limitations on using the public 2.4Ghz and 5.8Ghz bands just like computers are, they cannot exceed certain transmission levels so we can all share these bands without too much interference. It's the way DJI uses these frequencies that's unique and clever. What interesting is they don't sit still, Lightbridge has been going through an evolution over the last 3yrs, I think we're on version 4 now. I think the Ocu-Sync version used in the Mavic may be their best iteration so far, as it seems more reliable at distance. It also has the ability to have multiple receivers linked at the same time, like the wireless DJI goggles along with the RC display. I would expect P5 to be Ocu-Sync equipped, but with 2.4 and 5.8ghz bands.
 
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