Understanding ETSI EN 300 328: The Key Standard for 2.4 GHz Wireless Devices

ETSI EN 300 328 is a European standard developed by the European Telecommunications Standards Institute (ETSI) that defines the technical requirements for radio devices operating in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. It applies to wideband transmission technologies such as Wi-Fi (IEEE 802.11b/g/n), Bluetooth (both classic and BLE), Zigbee, and other similar wireless systems. Compliance with EN 300 328 is mandatory for CE Marking, allowing devices to be sold and operated legally across European markets.

The primary goal of this standard is to ensure that wireless devices can coexist efficiently within the crowded 2.4 GHz spectrum. To achieve this, the EN 300 328 sets limits and guidelines for several critical parameters, including:

Transmit Power: Devices must not exceed a maximum effective isotropic radiated power (EIRP) of 20 dBm (100 mW).

Spectrum Access: Technologies must implement techniques such as Listen-Before-Talk (LBT) or adaptive frequency hopping to minimize interference and promote fair spectrum use.

Receiver Performance: Devices must maintain strong operational integrity even when exposed to interference from other nearby devices.

Emission Control: Strict limits are placed on out-of-band and spurious emissions to prevent disruptions to other radio services.

EN 300 328 also requires devices that do not employ active channel assessment methods to adhere to duty cycle limits, ensuring that no device occupies a channel excessively at the expense of others. Unlike some standards that mainly focus on transmission characteristics, EN 300 328 emphasizes both transmission and reception robustness, making it particularly relevant in today's dense wireless environments.

The current version, V2.2.2, introduces tightened requirements around spectrum sharing and receiver blocking, reflecting ETSI's continued effort to improve coexistence and system reliability. These updates are increasingly important as the number of 2.4 GHz devices continues to grow, ranging from consumer electronics to industrial and medical applications.

In the United States, the closest equivalent to EN 300 328 is FCC Part 15 Subpart C, particularly Section 15.247, which governs spread spectrum and wideband transmitters operating in the same frequency band. However, ETSI’s requirements are generally stricter when it comes to coexistence mechanisms like LBT (Listen-Before-Talk), whereas the FCC places more emphasis on limiting interference without mandating specific spectrum access methods.