In a mine at a high altitude exceeding 4000 meters above sea level, with an extreme environment (high and low temperatures) and abundant dust, Mikrotik RBMETALG-52SHPacn radios were installed in mine operation trucks. Over time, the signal quality deteriorated until it was completely lost, requiring radio replacement. The installation was carried out following all manufacturer recommendations, yet the radios still failed.
The following hypothesis and analysis integrate real-world signal data obtained in the field, physical principles associated with electrostatic discharge (ESD) at high altitude, and a documentary comparison between commercial and industrial equipment used in mining. Tests were conducted with a batch of 10 MikroTik radios previously identified as degraded, and the same reception failure pattern was observed in all of them. Additionally, three new radios with active monitoring were installed to track their performance in the same environment.
- Field Data Observed on MikroTik Metal 52 ac Equipment: During field operations, the following parameters were repeatedly observed on MikroTik Metal 52 ac radios installed in trucks:
TX Power: configured between 23 and 27 dBm (within specification).
CCQ: low and unstable values (e.g., on the order of 10–20%), even with adequate transmission power and SNR.
SNR/Noise Floor: adequate values (noise floor close to -110/-114 dBm), ruling out channel saturation or significant external interference.
RX Rate: degraded reception rates were observed, reaching minimum values (1 Mbps), indicating that the rate adaptation algorithm forces low modulations due to persistent reception errors.
Temporal Behavior: the problem does not appear immediately; The degradation appears gradually, varying over hours, days, or weeks.
This pattern—normal TX with progressive loss of RX sensitivity—is characteristic of RF front-end degradation, particularly of the low-noise amplifier (LNA).
- Relationship between ESD, Altitude, and Observed Signal Pattern: From the physics of the phenomenon, the severity of electrostatic discharges increases significantly in environments such as:
Altitudes between 4,000 and 4,500 meters above sea level, with lower atmospheric pressure.
Extremely dry air, which favors the accumulation of electrostatic charge.
Operation on large, mobile metallic structures (trucks), with limited or variable ground reference.
(Conceptual model based on the physics of gas discharges and field observational evidence)
Under these conditions, ESD events do not usually cause immediate failure, but rather cumulative damage to sensitive RF receiver components. The typical result is exactly what is observed in the field:
operational transmission,
degraded reception,
unstable links and low CCQ,
non-simultaneous failures between identical devices.
This behavior is not associated with configuration errors or spectrum interference, but rather with electrostatic stress outside the device's design range.
- Scope of Certifications for the MikroTik Metal 52 ac Device: The manufacturer's public documentation for the MikroTik Metal 52 ac device only declares CE/FCC/IC regulatory certifications, focused on compliance with radio frequency regulations. The following are not declared in this documentation:
ESD immunity according to IEC 61000-4-2 (industrial level).
Electrical transient testing (IEC 61000-4-4/4-5).
Environmental testing according to IEC 60068 (vibration, shock, pressure/altitude).
Maximum certified altitude and no validation for industrial mobile platforms.
Therefore, from a regulatory standpoint, the equipment is a commercial outdoor solution, not certified for harsh industrial environments.
- Comparison with Rajant equipment used in mining: In contrast, Rajant equipment historically used in mining operations is specifically designed for open-pit mining and mobile platforms. This equipment:
Has industrial certifications for electromagnetic compatibility and environmental testing, including standards from the IEC 61000 family (ESD, transients) and IEC 60068.
Features multi-stage ESD protection and an industrial RF architecture.
Has been validated for operation in high-altitude and high-severity environments.
It should be noted that formal documentation of these certifications is usually provided during homologation processes, bidding processes, or under NDAs—standard practice in mining—and is not always publicly available. The operational stability of Rajant equipment in the field, compared to the degradation observed in commercial radios, reinforces the conclusion that the determining factor is the level of robustness and certification of the design, and not the environment alone.
- Technical Conclusion The correlation between:
the actual signal data observed in the MikroTik Metal 52 ac, the
