Which frequency bands do industrial wireless remote controls operate in?
Mostly licence-free short range bands are used: 433 MHz, 868 MHz and 2.4 GHz ISM. Power and duty cycle limits come from regulation, not the maker.
Industrial wireless remote controls mostly use the licence-free short range bands: 433.05–434.79 MHz, 863–870 MHz and the 2400–2483.5 MHz ISM band. The choice of band is not a marketing preference but a framework drawn by regulation; in Europe (CEPT) the limits are set by ERC/REC 70-03.
The bands and their limits
- 433.05–434.79 MHz: typically 10 mW ERP and 10% duty cycle for non-specific short range devices. Cheap, it diffracts well, but it is a crowded band full of garage remotes, car keys and telemetry.
- 863–870 MHz: generally 25 mW ERP and 1% duty cycle; only in the 869.4–869.65 MHz sub-band are 500 mW ERP and 10% duty cycle possible. Cleaner, but at the same distance it gives 6 dB more free space loss than 433 MHz.
- 2400–2483.5 MHz: 20 dBm EIRP and 10 dBm/MHz spectral density under EN 300 328 V2.2.2. Wideband and suited to frequency hopping; in return it is shared with Wi-Fi and Bluetooth and is the band that loses the most behind an obstacle.
Which site wants which band
| Site | Band that stands out | Reason |
|---|---|---|
| Behind obstacles, walls and concrete | Sub-GHz | A lower frequency reaches behind an obstacle better |
| Facility with heavy Wi-Fi use | Sub-GHz | The ISM band is shared and crowded |
| Many remote controls side by side | ISM, frequency hopping | Wideband, hopping reduces collisions |
| Continuous and frequent commands | Look at the duty cycle | The transmission time ratio limit restricts how often you can command |
A frequent mistake
The most common error is to equate the band directly with range. What determines the range is not the band itself but the output power, the antenna placement, the receiver sensitivity and what lies in between. The second common error is to guess the band on the product card: the practical consequence of the difference between the two families can only be assessed once the real band is known. The third is to take the duty cycle limit for a performance feature: this limit is not about how fast the device responds but about how long it may lawfully transmit, and in an application that sends commands continuously it directly settles the design.
Where this information is not enough
The limits above are the European framework, and band plans differ from country to country. The same device can be free to use in one country and subject to a different power limit in another. If you are sending a machine abroad, write the band of the remote control into the machine file as well; it is one of the first technical questions asked at customs or at commissioning. Whether a radio licence is required in Türkiye and what CE and the radio equipment directive bring with them are dealt with separately.
What to do
In practice the choice is made by balancing range, obstacle density and data rate. Do not guess which band is used in a product; look at the device label and at the harmonised standard number in the declaration of conformity. If the band is not written on the label, ask the supplier for it in writing and do not take a verbal statement as the record. If more than one remote control is to work on the site, write the band information into the installation file; that is the first thing to look at when a collision is being hunted later. If you are thinking of adding a second set afterwards, separate the band and channel arrangement at the first installation; adding to an arrangement that was separated from the start is easy, while separating one that was not means going over both systems.
The full topic: 433 MHz or 2.4 GHz?