This slide set is a short presentation that helps give the idea of a finite state machine. The phone is an example of a finite state machine. It has state, and events transition it from one state to another.
4. Waiting Dialling Wait for answer Event: Start calling λ You dial a number and start waiting for someone to answer the remote phone
5. Waiting Dialling Wait for answer Conversation Event: Start calling Event: Pick up λ Someone answers the remote phone and you talk to him (her)
6. Waiting Dialling Wait for answer Conversation Event: Hang up Event: Start calling Event: Pick up λ You finish your conversation and hang up
7. Waiting Dialling Wait for answer Conversation Event: Hang up Time out Event: Start calling Event: Pick up λ If nobody answers the remote phone, you hang up and the phone becomes idle again
8. Waiting Ringing Dialling Wait for answer Conversation Event: Hang up Time out Event: Incoming call Event: Start calling Event: Pick up λ If there is an incoming call then the phone starts to ring
9. Waiting Ringing Dialling Conversation Wait for answer Conversation Event: Hang up Time out Event: Answered Event: Incoming call Event: Start calling Event: Pick up λ If you answer the phone then you can talk to the remote person
10. Waiting Ringing Dialling Conversation Wait for answer Conversation Event: Hang up Time out Event: Answered Event: Incoming call Event: Start calling Event: Pick up Event: Hang up λ You hang up when you finish talking and the phone becomes idle again
11. Waiting Ringing Dialling Conversation Wait for answer Conversation Event: Hang up Time out Event: Answered Event: Incoming call Event: Start calling Event: Pick up Event: Hang up λ If nobody answers a ringing phone it will go back into an idle state Time out