Question : Prepaid Sim Cards billed?

basically i was wondering how prepaid cell providers charge their customers. I look for those with unlimited incoming minutes in countries but i was wondering a few things. Assuming that there is no connection fee on the call (like no 20 cent connection charge), if i call a person from the phone with a prepaid sim card and the person on the other line never picks up (no voicemail) just continuous ringing am i charged for that call. I mean i am hearing ringing an whatnot for like 45 seconds but the other side never picks up and i just hangup... is this using minutes, i have gotten a mixed response and i would like to know how that is billed (or not because the call never really went through)?

Answer : Prepaid Sim Cards billed?

>just continuous ringing am i charged for that call
normally: no.  there might be exceptions, but from what I know: charging only starts when the call is picked up (resp the mailbox turns on)

this is a feature of the backup switch that handles to call, to not generate billing information when the call did not start.

note: I am working as billing engineer in a telco company.