booster amplifier vs relay link

booster amplifier and relay link both are nouns.

Word	Noun	Adjective	Verb	Adverb
booster amplifier	Yes	No	No	No
relay link	Yes	No	No	No

As nouns, booster amplifier and relay link are synonyms defined as:

booster amplifier and relay link: an amplifier for restoring the strength of a transmitted signal

Other synonyms of booster amplifier include booster, booster station, relay station, relay transmitter.

booster amplifier (noun)	relay link (noun)
an amplifier for restoring the strength of a transmitted signal	an amplifier for restoring the strength of a transmitted signal