DJI drones send live video using DJI's own digital radio system, called OcuSync on older models and O2, O3, O4 or O4+ on newer ones. The drone compresses its camera feed and streams it, along with telemetry like altitude, speed and battery, over 2.4 GHz and 5.8 GHz radio to your controller or goggles. At the same time, your stick commands travel the other way on the same link. Current systems like O4 reach a rated 20 km under FCC rules with roughly 120 ms of delay on camera drones and as little as about 20 ms on FPV gear.
Uplink, downlink and telemetry
- Uplink: commands from the controller to the drone: stick inputs, camera settings, return-to-home.
- Downlink: the live video feed from the drone to your screen.
- Telemetry: the flight data sent with the video: GPS position, altitude, speed, distance, battery level, signal strength and warnings.
DJI combines all three into one two-way digital link. If the link drops, the drone follows its signal-lost setting, usually return to home.
DJI's transmission generations
| System | Example drones | Rated range (FCC) | DJI's lowest latency |
|---|---|---|---|
| O2 | Mini 3 | 10 km | About 200 ms |
| O3+ | Mavic 3 Pro, Mavic 3 Classic | 15 km | 120 to 130 ms |
| O4 | Air 3S, Mini 4 Pro, Flip | 13 to 20 km | About 120 ms |
| O4+ | Mini 5 Pro, Mavic 4 Pro | 20 to 30 km | About 120 to 130 ms |
Each generation added antennas, bandwidth and better interference handling. Live view on current models is up to 1080p at 60 fps on the controller.
How DJI goggles work
DJI's FPV goggles are the receiving end of the same kind of link, tuned for lower delay. The drone's air unit sends video to the goggles, which show it on two small screens, one per eye. Lower latency matters because you're flying by that image in real time.
- Avata 2 with Goggles 3: O4, 1080p/100fps, latency as low as 24 ms.
- O4 Air Unit with Goggles 3 in racing mode: 1080p/100fps, latency as low as 20 ms, rated 10 km (FCC).
DJI Goggles 3 work with the Avata 2, Neo, Air 3, Mini 4 Pro and O4 Air Unit. They don't work with the Air 3S, Mini 5 Pro or Mavic 4 Pro. See DJI goggles compatibility.
Why real range is shorter
DJI's figures are measured in open, interference-free conditions. In practice, range drops with:
- Buildings, trees and hills between you and the drone
- Wi-Fi and other radio noise in cities
- Antenna orientation on the controller
- Flying low, where the ground blocks the signal
The legal limit matters more anyway: in the US you must keep the drone within visual line of sight, which for a small drone is usually a few hundred yards. See what is VLOS.
Common signal problems
If the feed freezes or drops, see DJI no image transmission signal. DJI's 4G Enhanced Transmission backup isn't supported in the US; see DJI Enhanced Transmission.
Building your own FPV quad? The DJI O4 Air Unit brings DJI's digital video to custom builds at 8.2 g.
Related guides
- DJI O4 video transmission explained: range, latency and frequencies
- Analog vs digital FPV: which video system should you choose?
- Best drone video settings: frame rate, shutter speed and ISO
- DJI Goggles 3 OSD setup with Betaflight and the O4 Air Unit
- DJI O4 Air Unit: setup, range and compatible goggles
- Drone night photography and video settings
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