Why is a smart card needed in GSM, while it is not required in AMPS? Explain the logic behind this.

Question

What will be an ideal response?

Answer 1

GSM systems worldwide, feature a subscriber identity module (SIM) smart card,
which holds all of a subscriber’s personal information (including his phone
number) and phone settings. The card can be switched from phone to phone,
making the new phone receive all calls to the subscriber’s number. The SIM card
makes it possible to roam around the world where other GSM networks are
operating. Any GSM phone becomes immediately programmed after plugging in
the SIM card, thus allowing GSM phones to be easily rented or borrowed. SIM
cards can be programmed to display custom menus for personalized service. All
this information requires digital technology especially when digital transmissions
provide for highly private conversations and complex authentication schemes that
would allow the user to access certain privileges, something not found in the
analog radio frequency modulation (FM) that is used in AMPS. AMPS system
predates GSM, and hence functions more like a walkie-talkie almost exclusively
for voice transmissions, hence the need for complex operations that require the
usage of digital technology is not needed.