DJI Transmission System (Everything You Need to Know)

An essential feature behind a DJI drone that is often overlooked is the drone transmission system.

I have personally flown multiple DJI drones from different generations, and I can say – good heavens, what a difference!

DJI drones usually have the OcuSync transmission system, which is unique and proprietary to DJI. The transmission module is installed on all DJI drones and cannot be upgraded or changed, but it comes in different versions. And the flight range, penetration, controller compatibility, and a few more factors depend on it.

Here, I’ll share with you everything you need to know about the DJI transmission system, why it matters, the difference between them, and how we can identify one.

Behind DJI OcuSync: Factors & Analysis

A transmission system in a drone is one of the most critical parts without which a drone cannot fly at all. It simply cannot make a connection between a drone remote controller and the drone itself.

In consumer DJI drones, we have the OcuSync transmission system, which has two roles: 

- It captures live video and sends it back to the pilot. The pilot receives a live feed, which can be seen on the phone screen connected to the remote controller or the DJI RC with a screen incorporated. The OSD is also transmitted by the same module with all the information you need to see during a flight (battery left, signal strength, direction, etc.)

- The OcuSync on the drone also receives radio input. The pilot information is sent from the remote controller and received by the same drone module. 

In FPV, we have two different modules: the video module (VTX) and a separate radio RX module that receives input on a different protocol. But not with DJI.

Therefore, without a transmission system, you cannot control the drone or see a live feed.

» MORE: Long Range Drones: Ultimate Guide

What is the difference between various DJI transmission systems?

As drone technology evolves at an incredible rate, so does the DJI OcuSync. 

There are quite a few differences between the different versions, so let me help you understand what can be affected when you’re about to choose a drone based on this feature.

- Flight Range: The flight range is the first to be affected. Newer OcuSync versions always come with a significant improvement in flight range and signal strength between the radio and the drone. DJI has always done an excellent job in creating long-range drones, primarily because of their transmission systems.

- Flight Penetration: Flight penetration is yet another vital factor that we’ll often observe to improve with newer OcuSync systems. From flying a drone behind obstacles and trees to areas with significant interference, the signal penetration of a drone is directly impacted by the OcuSync transmission version.

- Live feed resolution and framerate: What we see on our phone or RC screen, the details we observe, come with a specific resolution and framerate. That’s yet another factor impacted by the OcuSync version. With the newer versions, the drone can transmit more data in real-time, hence taking advantage of better resolution and framerate.

- Latency: In drone terms, latency is the response time between the drone remote controller and the drone itself when we relate to radio transmission or between the drone video system and the image displayed related to the video transmission. Older OcuSync versions and cheaper radios will have slower response times.

- Compatibility: All these DJI drones with an OcuSync transmission system have to be compatible with a radio that supports the same protocol. That’s why never buy an RC unless you’re confident it’s compatible with your DJI drone.

» MORE: When Should You Upgrade Your Drone? (Read This First)

OcuSync versions

Let’s not jump ahead and start with the ancient technology found in the early version of drones that are not used anymore today. 

You may not be interested in that.

What you need to know is that currently, there are DJI drones in production as of today that use OcuSync versions 2.0, 3.0, 3+, and the latest, 4.0. We’ve flown drones with nearly all of them and have tested them thoroughly at Droneblog, so this is the voice of experience.

What’s the difference between these versions? How do they handle all these features?

I remember when I had my first Mavic Air, it struggled to go beyond 500 meters (0.3 miles) in the distance before breaking up the signal badly.

It was indeed that bad. As far as I know, it used some kind of dual-band Wi-Fi transmission technology. 

But it was an amazing first drone. I get goosebumps when I remember it. Let me share with you one image I was able to capture at a maximum distance before I completely lost connection in line of sight (so I remember)

Then, I upgraded to a Mavic 2 – my first “long-range” drone. What a difference between these two drones – what a DIFFERENCE!

Imagine this being only a few years back. Now, if we think about it, the transmission system in these drones was of the first and second generation, and as compared to today’s O4, we literally compare futuristic with ancient technology.

» MORE: Smart Features in Drones (Explained for Beginners)

OcuSync 2.0

From the first time it was released, the DJI OcuSync 2.0 with Mavic 2 in 2018, DJI drones started to be capable of flying long-range. 

Five years later, the OcuSync 2.0 is still in production with the new DJI Mini 2 SE and Mini 3 and can be found on multiple drones, including the DJI Mini 2, Mavic Air 2, Mavic 2 Pro & Zoom, Phantom 4 Pro V2 and DJI Matrice 300 RTK.

It was the first significant improvement to be able to see, on some drones, a live feed resolution of 1080p, enjoying the skies and observing nature on a large tablet with… again, goosebumps…

With the OcuSync 2.0, we were also able to fly our drones on dual-band 2.4 and 5.8ghz, and, depending on the drone, we could fly up to 3.7 miles in Europe and 6.2 miles in the USA.

The intermittent switching between these two bands was an important feature to observe with OcuSync 2.0 and changed the perspective on how a DJI drone flies in different environments.

OcuSync 3.0

As drone technology has evolved, we are now seeing the most used transmission system in all DJI drones: the DJI O3, or OcuSync 3.0

Surely, you’ve heard about the DJI Mini 3 Pro or maybe about the DJI Air 2S. Excellent drones, capable of flying long-range without issues.

That’s only because of the new and improved OcuSync 3.0 system over the older 2.0.

While the 2.0 version was very cost-effective, and we can often see it in budget entry-level drones, with the greater O3 power, there comes a higher price for these drones.

In terms of performance, the OcuSync 3.0 significantly improved over the 2.0.

Depending on the drone, we can see drones such as DJI Mini 3 Pro capable of flying up to 5 miles in Europe or 7.5 miles in the USA (in geo-restricted environments) or see a boost of flight distance up to 15.5 miles or 25km with DJI Mini 3 Pro and Intelligent Battery Plus.

What a difference! 

The OcuSync 3.0 also proved very capable of flying farther in heavy-interference areas, such as urban or downtown WiFi-choked environments. 

Moreover, we are now seeing the DJI RC-N1 and DJI RC (with screen), the two most used DJI controllers ever to boast full compatibility with all OcuSync 3.0 drones.

But in terms of compatibility, the DJI RC-N1 can also work with a few older O2 DJI drones, whereas both RC-N1 and DJI RC are compatible with a few OcuSync 3+ drones (from the Mavic 3 series). 

» MORE: DJI Mini 3 Pro: One-Year Review (Video)

OcuSync 3+

Moving on, the OcuSync 3+ is a minor improvement of the original O3 System that is found on most DJI drones nowadays.

Currently, we can see the OcuSync 3+ transmission system only on the most advanced consumer drones released by DJI, the Mavic 3 series. 

And that’s it.

Paying thousands of dollars for such drones, we had to see some advantage in terms of range and penetration, so we took this addition.

Moreover, these Mavic 3 drones are compatible with the professional-level radio controller, the DJI RC Pro, which takes full advantage of this new transmission system.

The same DJI RC Pro is also cross-compatible with the DJI Air 2S, which comes with the standard O3 version.

Moreover, the O3+ Mavic 3 drones are well-compatible with DJI RC and RC-N1 controllers that boast the O3 basic version.

See DJI? Cross-compatibility is possible! Why don’t we see it more often with newer drones?

Now, moving into the technical data of the DJI O3+, with the Mavic 3 series, we can realistically see a transmission range of 5 miles in Europe or 9.3 miles in the USA.

If we’re talking about unrestricted environments, the Mavic 3 drones can fly up to 18.6 miles or 30 kilometers.

What an improvement!

But the great advantage of the O3+ is that being hosted in a professional-level, commercial drone, we needed a more robust transmission to penetrate interference, to be able to take real-estate photographs, inspect a building, or do some mapping without having to deal with spotty connections.

The O3+ transmission system, the same as O3 and O2, operates on dual-band 2.4 and 5.8 GHz but at much greater power.

We can also see the live view image on 1080p at 60fps with the more expensive DJI RC Pro. 

» MORE: DJI Mavic 3 Pro Review (I have NEVER flown a drone that I enjoyed so much)

OcuSync 4.0

With 2023, we have a new era of high-end drone technology that surpasses anything ever manufactured, at a fraction of the price.

If you’re just about to get into the drone hobby, I strongly recommend, without any doubt, going either with the DJI Air 3 or DJI Mini 4 Pro.

Both these drones come with the latest transmission technology, the OcuSync 4.0 (and much more).

After several years of enjoying drones at the top of the line in terms of transmission power with the OcuSync 3.0, now those drones look like toys in comparison with O4.

No joke here.

The OcuSync 4.0 is currently the most powerful transmission module found in basically any consumer drone.

We’re still limited in Europe with a realistic range of 6.2 miles or 10km, but in the United States… well… I’m wondering how, but both the Air 3 and DJI Mini 4 Pro are restricted to 12.4 miles or 20km in transmission range.

That is way beyond the visual line of sight if we’re following the drone laws.

But in reality, with no restrictions, the O4 transmission system is capable of flying a competent drone for up to 20 miles or 32 km.

See where we got? How can I compare such drones with the 0.3-mile transmission on my old Mavic Air? It’s good that I’ve sold it, though.

And that’s how drone technology has evolved in the past few years. What should we expect in the next 5 or 10 years?

On the technical side, the DJI O4 uses the same 2.4 and 5.8 GHz dual-band transmission, has a low latency of up to 120ms, and this new OcuSync system is compatible ONLY with two new remote controllers:

The DJI RC-N2 and DJI RC 2. 

We’re glad to see it this way only to obtain the best transmission system. 

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