This 'Triple A' set stands for Authentication, Authorization, Accounting, and the theme of this book is maintaining security in a wireless cell-phone network.
Authentication is a three way street. Is the device being used really the correct device to receive the service being requested? And is the network being accessed really the network you want to be on? The third type of authentication is on a message level. Is the message itself legit, or did someone, somehow get in the middle and send a bogus message?
Authorization is rather like the old 'need to know' aspect of security. Is the salesman out in the field that's calling in really authorized to get employee or financial information?
Accounting includes making sure that the client is billed the correct amount of time, but also includes such things as system usage analysis to help define capacity planning.
Each of these subjects is exhaustively treated in this book. Further they are handled with a casual writing style that makes the book more enjoyable to read than most. Well, maybe enjoyable isn't exactly the right word -- how about making it possible to get through it without falling asleep.
