The decision you should be able to make
Select a candidate band while documenting the risks it transfers to clearance, capacity and reliability.
Core engineering
For identical path geometry, lower frequency has a larger first Fresnel zone. Lower frequencies may be less affected by some blockage mechanisms, but penetration, diffraction and clutter loss depend on material, geometry and model; 'lower always penetrates better' is not a design rule.
Higher-frequency systems can use compact high-gain antennas, but alignment sensitivity, rain, gaseous absorption and hardware limits become increasingly important in microwave and millimetre-wave bands.
Spectrum authorisation, device class, EIRP, DFS, AFC, indoor/outdoor limits and coordination are country-specific and can change.
Equipment and field checks
- Compare certified regional variants, supported channel widths, antenna options and receiver thresholds at the intended modulation.
- Check whether the radio reduces conducted power at higher modulation, channel width or temperature.
- Do not buy equipment until the exact band and operating mode are lawful at both endpoints.
Do not progress until
At least two candidate bands have been compared for clearance, predicted receive level, interference, availability, capacity and authorisation.
Limits and cautions
- Band comparisons are conditional on the same service target and stated equipment. Marketing range figures are not propagation evidence.
Primary sources
Sources were checked for this technical review. Recheck regulator and equipment requirements at the point of design or installation.