You have probably seen business men/women running round
looking important.
Security Guards, Police AOS, Couriers, Ambulance,
Fire, Real estate agents all use
this mode to send text messages between the control
room and the person in the field.
Pagers come in three basic forms:-
Tone
These pagers only start beeping when called.
Number
These just receive numbers.
Alphanumeric
These receive full text messages.