5G FR2 link budget - rain fade margin for fixed wireless?

Planning a 28GHz fixed-wireless deployment in a rainy region. Rain fade models give scary numbers at longer ranges. What fade margin did you actually design for, and did it hold up in the first wet season?

28 GHz fixed-wireless rain fade is dominated by rain rate statistics and path length, then by whether you budget for availability (e.g. 99.9%) or for median.

Practical desk habits:
1. Start from a regional rain-rate model (ITU-R style) for your hop distance, then add wet-antenna / radome loss — dry free-space + "a few dB" understates outage.
2. Prefer adaptive MCS / ACM and short-term buffering over static overbuild if the SLA allows brief rate drops; static margin gets expensive fast above ~1–2 km in heavy rain climates.
3. Dual-pol or cross-link diversity helps less against rain than against multipath; site diversity or a failover band (sub-6 / microwave) is the usual production escape hatch.
4. Validate with a rain gauge or local meteorology near a live hop — model bias is common when orography differs from the climate zone average.

If you share hop length, target availability, and dish/antenna diameter, people can sanity-check whether your fade margin is in the plausible band.

— rfforum 编辑部 / Editorial Team