| The system
is comprised of three separate entities. The mobile station
provides two functions, the hardware, which is generic to
any user, and the Subscriber Identity Module or SIM, which
assigns an identity to the user and the hardware.
This part of the system allows
the user to make and receive calls. The next portion is the
base station substation, which consists of two parts, the
base transceiver station and the base station controller.
The base transceiver station
recognizes the cell and handles the interface. The base station
controller manages the resources of the base transceiver stations.
The last piece to the puzzle and possibly the most complicated
is the network subsystem.
Simply put the network subsystem
combines with four databases to provide all of the functionality
to operate the whole process. It authenticates the caller,
updates the caller’s locations, registers a caller,
routes callers during roaming and much more.
As you can see this is an
intricate system of intertwined elements that form a unified
ability to make seamless cell phone calls. |
