What factors are required to establish a high quality 2.4 GHz point-to-point RF link at a distance o

What factors are required to establish a high quality 2.4 GHz point-to-point RF link at a distance of miles (5 kilometers)? Choose 2

A.
Accurate Link Budget calculations

B.
Accurate Earth Bulge calculations

C.
System Operating Margin (SOM) of at least 20 dB

D.
A minimum antenna gain of 13dBi

E.
A Fresnel Zone that is at least 60% clear of obstructions