This TS specifies the stage three Protocol Description of the Advice Of Charge (AOC) service, based on stage 1 and 2 of the ISDN Supplementary Service Advice Of Charge for all calls (permanent mode). Within the TISPAN NGN Release 2 Next Generation Network (NGN) the stage 3 description is specified using the IP Multimedia Call Control Protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP).
Three AOC services exist:
Charging information at communication set-up time (AOC-S)
The AOC-S service enables a user to receive information about the charging rates at communication set-up time and also to receive further information during the communication if there is a change of charging rates.
Charging information during the communication (AOC-D)
The AOC-D service enables a user to receive information on the recorded charges for a communication during the active phase of the communication.
Charging information at the end of the communication (AOC-E)
The AOC-E service enables a user to receive information on the recorded charges for a communication when the communication is terminated.