Drones are an emerging technology that has seen rapid development and adoption in recent years, finding widespread application in various fields. As drone applications continue to expand, the signal frequency bands they utilize are becoming increasingly diverse.
What frequency do drones use?
Main frequency bands used by drones
1. 2.4 GHz band (e.g., 2.400 - 2.483 GHz)
2.4 GHz wireless technology has become the mainstream transmission technology for wireless products. The so-called 2.4 GHz band refers to an operating frequency range of 2400 MHz to 2483 MHz, which is license-free worldwide. Common WiFi, Bluetooth, and ZigBee all use the 2.4 GHz frequency band.
WiFi, Bluetooth, and ZigBee are all based on the 2.4 GHz frequency band, but they employ different protocols, resulting in different transmission rates and therefore different application ranges. While all using the 2.4 GHz frequency as a carrier, the communication methods derived from these different protocols can be vastly different. The difference in data transmission speed alone can range from 1 Mbps to 100 Mbps.
The 2.4 GHz band is one of the most common frequency bands used by drones. It's a radio frequency band primarily used for WiFi and Bluetooth communications. This band has a wide coverage range and relatively fast transmission rates, making it widely used for remote control and image transmission in drones.
2. 5.8 GHz Band (e.g., 5.725 - 5.850 GHz, the specific range varies by country)
The 5.8 GHz band is one of the most common frequency bands used by drones. It's also used for WiFi and Bluetooth communications and is widely used in drone image transmission systems, including high-definition image transmission signals. Some high-end drones also use this frequency band for some control signals. Compared to the 2.4 GHz band, the 5.8 GHz band has a faster transmission rate but a smaller coverage range.
Advantages and Disadvantages of the 2.4 GHz and 5.8 GHz Bands
Advantages and Disadvantages of the 2.4 GHz Band
Advantages:
Strong penetration: The longer wavelength allows for slightly better obstacle avoidance than the 5.8 GHz band and is more stable in complex environments. Longer Range: At the same power level, it typically transmits farther than 5.8GHz.
Disadvantages:
Severe Interference: This is a very crowded frequency band. Various home wireless devices, such as Wi-Fi, Bluetooth, and Zigbee, operate in this frequency band, which can easily cause signal interference.
5.8 GHz Band Advantages and Disadvantages
Advantages:
Less Interference: Relatively clean and rarely used by home devices, resulting in a purer signal and potentially lower latency, making it suitable for transmitting high-quality video.
Broader Band: Supports higher bitrates and clearer video transmission.
Disadvantages:
Weak Penetration: The shorter wavelength is easily blocked by obstacles such as walls and trees, and the transmission range is not as good as 2.4GHz in obstructions.
3. GPS Satellite Signal Band - 1.5GHz Band
The GPS satellite signal band is a frequency band used for drone positioning. It can accurately determine the drone's position, enabling flight path planning and tracking. GPS satellite signals are also one of the keys to enabling autonomous flight and formation control for drones.
4. Remote Control Signal Band - 900 Band
The remote control signal band is a type of radio frequency band used for drone remote control. It connects the drone's flight controller to the remote controller, enabling remote control of the drone within a certain range. This frequency band has a limited application range, but it plays a crucial role in drone remote control.
Advanced Drone Frequency Technology
Mainstream consumer and professional drone manufacturers like DJI and Autel don't simply operate on a single frequency. They employ more complex technologies to ensure signal stability:
Adaptive Frequency Modulation: The drone scans the 2.4GHz and 5.8GHz bands in real time, automatically selecting the channel with the least interference for communication. During flight, it may seamlessly switch between dozens of channels without you noticing.
Simultaneous Dual-Band Operation: Many drones support dual-band operation simultaneously. For example:
The remote controller uses 2.4GHz for control (for stability and range).
The image transmission uses 5.8GHz for video transmission (for high definition and low latency).
Or, it can automatically switch roles based on environmental conditions for optimal performance.
Technologies such as OcuSync, O3, and LightBridge: These are DJI's proprietary protocols, essentially operating on the 2.4GHz and 5.8GHz public frequency bands. They utilize advanced algorithms (such as anti-interference coding and MIMO multi-antenna technology) to significantly improve transmission range, stability, and video quality. While they still operate within these two frequency bands, their efficiency and reliability far exceed those of standard Wi-Fi image transmission.
5. Other Frequency Bands
900 MHz and 433 MHz Bands: Some professional drones or long-range extended-range systems used in industrial and surveying applications may utilize these low-frequency bands. Their longer wavelengths and strong diffraction resistance allow for very long transmission distances, making them ideal for beyond-visual-line-of-sight flight in complex environments such as mountainous areas and urban areas. However, due to their limited bandwidth, they are typically used only for control signals, not image transmission.
1.2 GHz and 1.3 GHz Bands: These are amateur radio bands, permitted in some countries. They are commonly used by FPV (first-person view) racing drone enthusiasts for image transmission, achieving lower latency and improved penetration. Please note that in many regions, the legal use of these frequency bands requires a radio operating license.
Regulations in Different Countries
Drone frequency usage must comply with the radio regulations of the country in which it is used.
China: Strictly adhere to SRRC certification. Both 2.4GHz and 5.8GHz are open frequency bands for use.
US: Comply with FCC regulations. The specific range of the 5.8GHz band differs slightly from that in China.
Europe: Compliance with CE certification and the RED directive is required.
