When a cellular phone is turned ON, but not yet engaged in a call, it first scans the group of forward control channels to determine the one with the strongest signal, and then monitors that control channel until the signal level drops below a usable level.

Call initiation by a landline (PSTN) subscriber to mobile user:

• The mobile switching centre (MSC) dispatches the request to all base station in a cellular system.
• The Mobile Identification Number (MIN) which is subscriber telephone number is then broadcast as a paging message over all of the forward control channels throughout the cellular system.
• The mobile receives the paging message sent by BS which s monitors, and responds by identifying itself over the RCC.
• The BS relays the acknowledgement sent by the mobile and informs the MSC of handshake.
• The MSC instructs the BS to move the call to an unused voice channel pair within the cell.
• The BS signals the mobile to change frequencies to an unused forward and reverse voice channel pair.
• Another data message is transmitted on forward channel to instruct the mobile telephone to ring and mobile user to answer the phone.
• Figure below shows sequence of events involved in call connection.