Knowledge Base

RED certification with LoRa

Hi all,

I am developing a product using Murata CMWX1ZZABZ-078, that is to say STM32L072CZ + SX1276. I would like to get the CE certification (AKA RED

The classic LoRaWAN libraries have some basic test functions that are not appropriate to "official" RED tests. Long story short, the aim of RED certification is checking that the whole product is behaving correctly in terms of:
- susceptibility (the device does not reboot when someone is giving a phone call next to it)
- emission (the device does not speak to loud, in the right frequency bands).

Looking at the available test functions:
- the AT commands of the LoRaWAN extension software of STM32 has functions that set the Data Rate, the Transmit Power, ETSI Duty Cycle, Spread factor, Coding Rate) and start tone test (that is to say, not LoRa, just playing with the 868 MHz transceiver). There is also a certification mode that is simply sending dummy data at a high rate (using LoRaMacTestSetDutyCycleOn in LoRaMacTest.h that allows bypassing of the 1% time-regulation).
- lora-test.c (in middle-ware) has compliance test functions that can check the operation of the library itself (LoRa link integrity)

These functions can be useful for debugging but RED certification tests require something different. Again, the goal of these tests is checking that the whole device is running correctly while respecting the RED. For the susceptibility test, an antenna is emitting radio waves on one face of the device, from 80 MHz to 6 GHz. For each frequency (10% shift between 2 tests), the device should be able to measure and send data. All configurations have to be tested (all frequencies, all faces of the device, all spread factor, all LoRa bands)... This is *very* long (that is to say: *very* costly). So here are some ways to shorten it:
- using max power all the time
- using extreme spread factors (SF7 and SF12)
- using a single channel width (already the case in region EU868: 125kHz)
- using extreme bands (in case of region EU868, band are 868,1 ; 868,3 ; 868,5 so basically one should disable the centred one)
- bypassing the LoRa duty cycle (and be able to send continuously)

Do someone has experience with the RED certification?
Is there a "clean" way to set the LoRa configuration for this tests?


Please contact you ST support for code generated by STM32Cube