AMPS Call Processing
AMPS call processing diagram -- Keep track of the steps!
Let's look at how cellular uses data channels and voice channels. Keep in mind the big picture while we discuss this. A call gets set up on a control channel and another channel actually carries the conversation. The whole process begins with registration. It's what happens when you first turn on a phone but before you punch in a number and hit the send button. It only takes a few hundred milliseconds. Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls. What cell folks call pages. If the mobile is roaming outside its home area its home system gets notfied. Registration begins when you turn on your phone.