phone number vs signalling

phone number and signalling both are nouns.

Word	Noun	Adjective	Verb	Adverb
phone number	Yes	No	No	No
signalling	Yes	No	No	No

As nouns, signalling is a hypernym of phone number; that is, signalling is a word with a broader meaning than phone number:

Other hypernyms of phone number include sign, signal, signaling.

phone number (noun)	signalling (noun)
the number is used in calling a particular telephone	any nonverbal action or gesture that encodes a message