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📡 IEC 60487: Microwave Radio Relay Equipment Measurement — The Link Health Check
📅 Standard: IEC 60487-3:1975 | 🔗 Prepared by: IEC TC 102 — Radiocommunication
Terrestrial microwave relay systems form critical backbone links in telecommunications networks. IEC 60487 specifies measurement methods for key parameters: transmit power, receiver sensitivity, BER, and phase noise.
📋 Key Measurements
| 📡 Parameter | 📋 Significance | 📐 Typical Value |
|---|---|---|
| Tx power | Determines link range | +30 to +40 dBm |
| Rx sensitivity | Minimum detectable signal | -90 to -100 dBm |
| BER | Digital transmission quality | < 10⁻⁶ |
| Phase noise | Affects high-order modulation accuracy | < -90 dBc/Hz @ 10 kHz |
⚡ Engineering Insight
⚠️ Engineering Insight: The stealthiest issue in microwave link commissioning is multipath fading — frequency-selective fading from interference between the direct and ground-reflected paths. IEC 60487 BER testing under AWGN cannot fully represent real multipath channel conditions. Engineering practice requires 20–30 dB fade margin above the thermal noise threshold to achieve carrier-grade reliability (99.999%).
⚠️ Common Mistakes
❌ Mistake 1: Missed Antenna Feedline Mismatch
Impedance mismatch causes excessive reflected power — reducing effective radiated power and potentially damaging the transmitter final stage.
❌ Mistake 2: Ignoring Rain Attenuation
Above 10 GHz, rain attenuation reaches 10–30 dB/km in heavy rain — link budgets must incorporate local meteorological data.
