Imagine being able to contact somebody at any time, no matter where they are! Back in the 20th century, this seemed an impossible dream, until the pager came along. By beeping or vibrating, it would alert you that somebody had sent their number and wanted you to call back On a landline.
Later versions allowed text messages to be sent and received. By the mid-1990s, millions were in use, and then mobile phones appeared. Now only doctors use pagers.
By the mid-1990s, millions were in use, and then mobile phones appeared. Now only doctors use pagers.
A pager is a very simple radio that listens to just one station all of the time. A radio transmitter broadcasts signals over a specific frequency. All of the pagers for that particular network have a built-in receiver that is tuned to the same frequency broadcast from the transmitter. The pagers listen to the signal from the transmitter constantly as long as the pager is turned on. Each pager has a specific identification sequence called a Channel Access Protocol (CAP) code. The pager listens for its unique CAP code. When it hears the code, it alerts the user and may provide additional information, depending on the pager type.
