TABLE OF CONTENTS There are many other processes a mobile telephone must perform to operate in a GSM network. The basic call processing operation of a mobile telephone includes initialization, call origination, call reception (paging), and handover.
When a subscriber unit is first powered on, it initializes by scanning for a control channel and tuning to the strongest one it finds. During initialization, it acquires all of the system information needed to monitor for paging messages and information about how to access the system. After initialization, the subscriber unit enters idle (sleep and wake cycle) mode and waits either to be paged for an incoming call or for the user to place a call (access). When a call is to be received or placed, the subscriber unit enters system access mode to try to access the system via a control channel. When access is granted, the control channel commands the subscriber unit to tune to a digital traffic channel. The subscriber unit tunes to the designated channel, and enters conversation mode. As the subscriber unit moves out of range of one cell site radio coverage area, it is handed over to a radio traffic channel at another nearby cell site.
Mobile telephone initialization is the process of a mobile device searching for a system broadcast radio channel, synchronizing with the system and obtaining system parameters that it will use to coordinate its access to the system.
Initialization phase begins when the mobile device is first turned on. It initially looks...
