Evaluation Of Radiated Electromagnetic Immunity Of The IoT LoRa Protocol
Authors: Ribeiro Jhonatan , Santos Eliton Smith Dos , Alencar David Barbosa De , Nascimento Manoel Henrique Reis Do , Santos Alyson De Jesus Dos 
Published: January 2025

Background: With the advancement of Industry 4.0, the automation of industrial processes has shifted from wired
communication technologies to wireless networks, enabling greater flexibility, efficiency, and scalability.
Technologies such as LoRaWAN and NB-IoT have been widely adopted due to their low energy consumption and
long-range communication capabilities, which are essential for industrial applications. However, the increasing
density of connected devices has introduced new challenges, particularly related to electromagnetic interference
(EMI), which can degrade network performance, cause packet loss, and delay communication.
EMI, caused by various sources such as electronic devices and natural phenomena, is a critical issue in industrial
environments. EMI simulations and analyses allow for network parameter adjustments and the implementation of
mitigation techniques, ensuring robust communications. This study's primary objective is to test the radiated
electromagnetic immunity of the LoRa protocol, assessing its ability to operate in environments subject to
electromagnetic interference. The research emphasizes the importance of understanding EMI impacts to preserve
data accuracy, improve communication performance, and ensure regulatory compliance, fostering a safe,
reliable, and efficient industrial environment.
Materials and Methods: The study evaluates the radiated electromagnetic immunity of Heltec LoRa ESP32 V2
boards, essential for IoT applications, in compliance with the IEC 61000-4-3 standard, which establishes methods
for testing immunity to high-frequency electromagnetic fields. The boards were tested in an anechoic chamber to
analyze the impact of radiated fields on LoRa communication. During the tests, conducted at frequencies from 80
MHz to 6 GHz and with a field intensity of 10 V/m, a transmitting board continuously sent LoRa packets while the
receiving board recorded RSSI values and packet reception rates.
The results demonstrated the sensitivity of the LoRa protocol to electromagnetic interference, evidenced by RSSI
variations and packet losses under certain conditions. The tests highlighted the importance of robust
configurations to maintain data integrity and device functionality in challenging industrial environments. The
study provides valuable insights for improving electromagnetic compatibility in Industry 4.0 and IoT applications,
meeting the criteria established by the IEC 61000-4-3 standard.
Results: The study identified critical communication disruptions in the LoRa system at specific frequencies (305
MHz and 730 MHz) under radiated electromagnetic fields with a power of 1.5 dBm, characterized by packet loss
and performance degradation. At 3 dBm, total communication failure occurred, attributed to internal resonances
in the RF components and insufficient shielding or filtering of the modules. The interference likely overlapped
with harmonics of the LoRa signal, reducing its ability to distinguish useful signals from noise. These findings
highlight the system's vulnerability to specific EMI conditions, emphasizing the need for improved filtering,
shielding, and protocol adjustments to enhance robustness in industrial environments.
Conclusion: The study finds LoRa unstable at 305 MHz and 705 MHz with 1.5 dBm, causing packet loss and potential communication failure, highlighting the need for mitigation in high-interference environments.