ETSI EN 300 328 Compliance: 2.4GHz Device Testing Guide
If your product transmits in the 2.4 GHz band, ETSI EN 300 328 sets the technical bar you must clear before you sell it in the European Union. The standard covers key requirements for transmitter performance, emissions, receiver behavior, and spectrum sharing.
What You’ll Learn:
- Which wireless technologies fall under EN 300 328
- Where the standard sits under EU law, and its current version
- The core tests your device must pass
- What happens when a device fails
- How MiCOM Labs tests your device, from submission to report
What ETSI EN 300 328 Covers
ETSI EN 300 328 is a harmonized standard under the EU Radio Equipment Directive 2014/53/EU (RED). Its full title reads “Wideband transmission systems; Data transmission equipment operating in the 2,4 GHz band; Harmonized Standard for access to radio spectrum.” The standard’s current edition, V2.2.2, published July 24, 2019, is still the version regulators recognize today.
The standard applies to wideband transmission equipment operating between 2,400 MHz and 2,483.5 MHz. Wi-Fi devices built on IEEE 802.11 fall under it. Bluetooth devices fall under it. Zigbee and other frequency-hopping IoT devices fall under it too.
When your device meets EN 300 328, you prove something specific: it uses radio spectrum efficiently, which is what RED requires. That proof becomes the core of your technical file. Your notified body checks that file before you can move toward certification.
| Attribute | Detail |
| Frequency Band | 2,400 to 2,483.5 MHz |
| Governing Directive | EU Radio Equipment Directive 2014/53/EU (RED) |
| Current Standard Version | EN 300 328 V2.2.2 (July 24, 2019) |
Which Products Need This Testing
Any device that transmits wideband signals in the 2.4 GHz band must undergo EN 300 328 testing before entering the EU market. Your device’s category shapes which test suite applies. A stand-alone Wi-Fi router faces a different set of checks than a Bluetooth wearable does, because the radio module, antenna design, and intended use all factor into the test plan a lab builds for your device. The table below groups the products we test most often at MiCOM Labs.
| Device Category | Common Examples |
| Wi-Fi Networking Gear | Routers, access points, mesh systems |
| Bluetooth Accessories | Headphones, speakers, wearables |
| Zigbee and IoT Sensors | Smart locks, thermostats, industrial sensors |
| Wireless Peripherals | Keyboards, mice, presentation clickers |
Core Test Requirements
EN 300 328 testing checks your device across several technical areas. Each one catches a different way a device could interfere with other equipment sharing the band. A device passes only when it clears every applicable row. The exact test sequence depends on your device’s modulation type. It also depends on transmit power and adaptivity design.
| Test Area | What It Checks |
| RF Output Power | Confirms transmit power stays within the 100 mW (20 dBm) EIRP limit. |
| Duty Cycle and Transmission Timing | Tracks how long and how often the device transmits within a hopping cycle. |
| Medium Utilisation | Measures how much of the channel the device occupies over time. |
| Power Spectral Density | Confirms transmitted energy doesn’t concentrate too heavily in a narrow slice of spectrum. |
| Adaptivity (LBT/DAA) | Verifies the device senses existing signals and avoids colliding with them. |
| Occupied Channel Bandwidth | Confirms the signal stays within its allocated channel. |
| Out-of-Band and Spurious Emissions | Measures unwanted emissions outside the intended transmission band. |
| Receiver Blocking and Spurious Emissions | Tests the receiver’s immunity to nearby interference. |
Not every device faces the same limits. Equipment that uses Listen Before Talk or Detect and Avoid, collectively known as adaptive equipment, faces more relaxed duty cycle limits because it actively senses and steers around other users of the band. Non-adaptive equipment transmits without first checking for other signals, so it faces stricter timing rules that cap how much of the channel it can use.
What Happens When a Device Fails
A failure doesn’t always mean starting over. If your device trips on just one clause, such as an out-of-band emission that exceeds the limit, you can often fix the firmware or filtering and retest that clause alone instead of running the full suite again. Catching problems during pre-compliance testing costs far less than catching them after a formal submission. It costs even more once products reach customers.
| Non-Conformance Outcome | Business Impact |
| Withheld Declaration of Conformity | You cannot self-declare RED compliance. |
| Blocked CE Marking | You cannot legally sell the device in the EU. |
| Product Recall | Units already shipped must be removed from the market. |
| Launch Delay | Retesting can add weeks to your go-to-market timeline. |
How MiCOM Labs Tests for EN 300 328 Compliance
MiCOM Labs runs EN 300 328 testing in-house, from the first pre-scan through the final report. Our engineers start with a pre-compliance scan that flags likely failure points early. We then run the full test suite against every clause your device triggers. When a test turns up a problem, our engineers flag it right away. They work with your design team to fix it before you submit for formal certification. You leave the process with a full report mapped to every applicable clause, ready to hand to your notified body or keep on file for your own compliance records.
This approach shortens your path to market. It also lowers your odds of a costly retest. If you’re preparing a 2.4 GHz device for the EU market, schedule a consultation with MiCOM Labs to scope your test plan.
Further Reading