RF Field Guide · reviewed reference
Spectrum bands and frequencies
Frequency sets wavelength, propagation behavior, antenna size, available allocations, and the rules that govern a deployment.
Question
How should a planner choose an operating band?
Inputs
- Jurisdiction and authorization
- Path length, foliage, rainfall, congestion, and required capacity
Answer
Working
Higher frequency means shorter wavelength. In free space, path loss rises by 6 dB when frequency doubles at fixed distance. That is only one term: diffraction, foliage, rain, antenna gain, and permitted operation also change the decision.
Visual explanation
- Authorization
- Path geometry
- Environment
- Equipment limits
- Channel plan
- Availability target
Interpretation
‘Unlicensed’ does not mean unregulated or interference-free. In the United States, Part 15 defines specific operating conditions; other jurisdictions use their own rules and coordination processes.