When compared to hf communications, which of the following advantages are ___

When compared to hf communications, which of the following advantages are unique to satellite communications links?

A. They are more reliable and flexible
B. They are unaffected by propagation variations affecting hf
C. They do not require repeater stations or troposcatter links
D. Each of the above

Show Answer

Answer: D

Share your understanding of this question with the correct explanation.