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Regulatory compliance for radio-enabled IoT devices using pre-certified radio modules

Posted by: Michael Lahrsen Date: 06 Jun 2024

pre-certified radio moduleThis article will review regulatory requirements defined by the Federal Communications Commission (FCC) / Innovation, Science and Economic Development Canada (ISED) and the European Radio Equipment Directive (RED) which define testing requirements that are widely accepted globally.

Many device manufacturers want to benefit from a wireless connection to the internet to enable and enhance advanced applications provided by their device. The integration of pre-certified radio module(s) into an electric/electronic host device enables the development of compliant products without deeper knowledge of the underlying radio technology. Major markets are governed by regulatory compliance rules as defined by FCC / ISED and RED.

FCC / ISED requirements for radio-enabled IoT devices using pre-certified radio modules

A prominent compliance route for FCC / ISED is to use a radio module certified as a “modular approval” transmitter and integrate it into a host device. The radio module is completely self-contained and usually only needs an input signal and power source to be functional. Although the host device integrating the “modular approval” transmitter does not require certification, the manufacturer still must account for all FCC / ISED compliance requirements, including electromagnetic compatibility (EMC) requirements for the digital circuitry and transmitter radio requirements. The host device manufacturer is responsible to follow the integration guidance issued by the radio module manufacturer per FCC / ISED rules. In addition, the host device manufacturer should perform a limited set of transmitter module verification tests to ensure the final product is in compliance with the FCC / ISED rules.

RED requirements for radio-enabled IoT devices using pre-certified radio modules

Under RED requirements, there is no “modular approval” route to compliance.

A manufacturer integrating a radio module into an electric/electronic host device is creating a new radio product that is now in scope of the RED. The host device manufacturer must make sure that the integrated radio module is compliant with the RED, as represented by the assigned CE mark and the Declaration of Conformity issued by the radio module manufacturer. The accompanying technical documentation is allowing the host device manufacturer to gain confidence that the radio module complies with all RED requirements. Also, under RED, the host device manufacturer is responsible for following the integration guidance provided by the radio module manufacturer along with its intended use. Finally, the host device manufacturer should perform a limited set of radio module verification tests to ensure the final product complies with EMC and RED requirements which contain receiver tests in addition to transmitter tests.

Technical Documentation

For both major schemes, FCC / ISED and RED, the radio module manufacturer should provide technical documentation on how the radio module complies with RF exposure and transmission power requirements and information about the intended use environment and associated limitations. The host device manufacturer then needs to make sure that compliance to RF exposure and transmission power requirements have been maintained after integration of the radio module into the host device.

As a minimum, EMC requirements need to be tested on the host device along with a representative re-test of radiated spurious emissions (RSE). For both, intended use and worst-case operating conditions are in scope. Both test disciplines require that the radio module is configured to use a radio channel with well-defined physical layer characteristics like transmit power, frequency band, test channel number, channel bandwidth, waveform, modulation and channel utilisation to name the most important.

For lower complexity radios, like Wi-Fi and Bluetooth, these parameters can usually be set by regulatory test modes. However, for complex cellular radio technologies as (E)GPRS, WCDMA, eMTC, NB-IoT, LTE and 5G NR regulatory test modes are not available.

This is where TÜV SÜD is supporting host device manufacturers that have integrated pre-certified radio modules.

We have base station simulators covering all above-mentioned cellular radio technologies, which we can flexibly configure to control all of the above physical layer parameters via over-the-air (OTA) signalling sent to the radio module. Hence, we stimulate the radio module receiver and transmitter to establish the intended worst-case operation mode for EMC and RSE testing.

As already mentioned, the wireless host device manufacturer’s main interest is to enable a wireless connection to the internet by integrating a radio module. But that brings another practical challenge which TÜV SÜD can help overcome: Many host devices require a live connection to the internet to allow keeping the embedded radio module in transmit (TX) mode for extended periods as needed during EMC or RSE testing in an anechoic chamber. If you’re wondering how to get the internet connection to the equipment under test (EUT) within the anechoic chamber, TÜV SÜD has a solution!

We connect the internet via LAN cable to our base station simulator thereby enabling the internet traffic to be sent two-way on the IP layer using the active radio connection which is already established for EMC or RSE testing.

Explore our electromagnetic compatibility (EMC) testing and RF testing services to find out why our clients trust us to support them with their product compliance.

Please contact us to discuss your project requirements.

 

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