Let me say we go to the airport and pick up a friend. The flight has arrived and the crowd has disappeared. But we haven't seen our friend. In such a case, we may go to some service desk and "page" our friend through the load-speakers. We can talk the airport staff at the service desk: "Excuse me, I wanna page my friend from Vancouver. His name is Mike Woodhead....."
Now let me assume we fifteen people are going to some park and have a picnic. Of course, we need to coordinate our actions. In such case, we may tell the coordinator or organizer: "Please keep me paged."