Calling up and Pick up

Pick up and calling up are semantically related. in telephone topic. In some cases you can use "Pick up" instead a verb "Calling up", when it comes to topics like communicate through telephone system.

Pick up verb - To acquire complete knowledge, understanding, or skill in.

Calling up and pick up are semantically related. Sometimes you can replace term "Calling up" with "Pick up", this phrasal verbs are similar.