ETSI TS 132 280 specifies the Advice of Charge (AoC) framework for relevant events, sessions, and services. The 3GPP umbrella charging architecture and principles are defined in TS 32.240 [1].

The AoC framework detailed herein provides for both offline and online charging models. It specifies the following:

• The AoC architecture.
• The common principles that govern AoC.
• The AoC function that enables the IMS AoC framework.
• Exemplary message flows.
• AoC interface data description.

All terms, definitions and abbreviations used in the present document, that are common across 3GPP TSs, are defined in the 3GPP Vocabulary, TR 21.905 [100]. Those that are common across charging management in 3GPP network, services or subsystems are provided in the umbrella document TS 32.240 [1] and may be copied into clause 3 of the present document for ease of reading. Finally, those items that are specific to the present document are defined exclusively in the present document.

Requirements that govern the AoC work are specified in TS 22.115 [101].