Description
The Event Based Charging Function (EBCF) is a fundamental component within the 3GPP Online Charging System (OCS). Its role is to execute charging logic in real-time for service events. Unlike session-based or volume-based charging, which are continuous, event-based charging is triggered by discrete occurrences. The EBCF receives charging events from network functions like the Gateway GPRS Support Node (GGSN), Packet Data Network Gateway (PGW), or IMS Call Session Control Functions (CSCFs) via the Ro or Gy reference points. These events carry information such as the subscriber identity, event type, and relevant service parameters.
Architecturally, the EBCF resides within the OCS and works in conjunction with the Account Balance Management Function (ABMF) and the Rating Function (RF). When a charging request arrives, the EBCF processes it. It first performs subscriber identification and retrieves the relevant account information and charging rules from the ABMF. It then uses the RF to determine the monetary or non-monetary cost (in units like credits) associated with the specific event. This rating can be complex, depending on factors like event type, service type, location, time of day, and subscriber tier. After rating, the EBCF instructs the ABMF to deduct the appropriate amount from the subscriber's balance in real-time.
How it works is centered on policy and real-time authorization. For each event, the EBCF must make an immediate decision: authorize the event (if sufficient balance exists) or deny it. For example, when a user sends an MMS, the MMS server sends a charging event to the OCS. The EBCF rates this 'MMS submission' event, checks the balance, and if authorized, allows the MMS to be sent while deducting the cost. It then returns a response to the network element. The EBCF supports various event types, including service events (e.g., content download, SMS, MMS), service configuration events (e.g., activating a call forwarding rule), and management events (e.g., balance top-up). It generates Charging Data Records (CDRs) for billing and auditing purposes.
Purpose & Motivation
The EBCF was created to address the limitations of traditional, simplistic charging models based solely on call duration or megabyte counts. As mobile networks evolved to offer a vast array of services beyond voice—such as messaging (SMS/MMS), content downloads, location-based services, and IMS features—operators needed a flexible way to charge for these discrete, non-continuous transactions. A flat data rate or per-minute voice charge could not capture the value or cost structure of sending an MMS or accessing a premium game level. The EBCF provides the mechanism for this granular, service-aware charging.
Introduced in Release 8 as part of the enhanced OCS architecture, the EBCF solved the problem of real-time credit control for event-based services. It enabled prepaid offerings for non-session services, which was a major business requirement. Without it, operators would have to rely on less accurate offline charging or forced all services into session-based models. The EBCF allows operators to define sophisticated tariff plans that charge different amounts for different types of events, fostering service innovation and personalized pricing. It is a key enabler for the monetization of the vast service ecosystem in modern mobile networks.
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (55 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-8, normative work from Rel-15.
In Release 15, the Event Based Charging Function (EBCF) was newly introduced as part of the 5G converged charging architecture, which is specified in the TS 32.29x series of documents. This introduction included the definition of the EBCF within the common charging principles and its integration into the new service-based architecture, utilizing the Northbound API for charging interactions as outlined in TS 32.290. The function is part of the broader framework enabling online and offline charging for 5G domains like data connectivity and edge computing.
- Introduce the Northbound API charging TS 32.240CR0394
- Introduction of 5G in charging architecture TS 32.240CR0396
- Introduction of 5G converged charging TS 32.240CR0397
- Introduction of 5G service based interface TS 32.240CR0398
- Introduction of 5G in charging mechanisms TS 32.240CR0399
- Introduce the 5G charging in clause 3 TS 32.240CR0401
+ 4 more changes
In Release 16, the key update for the Event Based Charging Function (EBCF) was the introduction of the Access and Mobility Management Function (AMF) into the charging architecture. This change integrated the AMF as a new entity within the common charging framework, enabling it to generate charging events for the 5G connection and mobility domain. This expansion allowed for the charging of mobility and session management events as defined in the 5G system specifications.
- Introduction of AMF in charging architecture TS 32.240CR0409
In Release 17, the Event Based Charging Function (EBCF) architecture was enhanced to support new 5G capabilities, including the formal introduction of charging for 5G LAN services and Edge Computing. The architecture was also updated to incorporate the 5G DDNMF (Data Delivery Network Management Function) and to refine the logical ubiquitous charging architecture by adding and later removing the PGW from its service-based interface representation. Furthermore, corrections and clarifications were made to the overall charging architecture, converged charging functions, and network slice charging.
- Add PGW in logical ubiquitous charging architecture- service based interface TS 32.240CR0413
- Introduction of 5G DDNMF in charging architecture for 5GS TS 32.240CR0429
- Addition of the 5G LAN service charging TS 32.240CR0434
- Charging architecture for Local Breakout TS 32.240CR0439
- Addition of the architecture for 5G LAN charging TS 32.240CR0442
- Enhance charging architecture for Edge Computing TS 32.240CR0443
+ 7 more changes
In Release 18, the Event Based Charging Function (EBCF) saw enhancements to support new services and architectures, including the addition of charging for Time-Sensitive Networking (TSN) services and 5G Satellite access. The release also introduced a converged charging architecture and expanded Business-to-Business (B2B) charging principles, alongside clarifying the charging architecture for the MB-SMF and roaming slice-aware charging.
- Adding New Consumer for MMS in Charging Architecture TS 32.240CR0446
- Slice-aware charging for Roaming partners TS 32.240CR0467
- Add MB-SMF in charging architecture for 5GS TS 32.240CR0470
- Add charging support for TSN service TS 32.240CR0473
- Add annex for B2B charging TS 32.240CR0474
- Update B2B charging principles TS 32.240CR0475
+ 13 more changes
In Release 19, the Event Based Charging Function (EBCF) was enhanced to support new services and architectures, including charging for AIoT (Artificial Intelligence of Things) services and for CAPIF (Common API Framework) service exposure. The release also introduced charging principles for Unmanned Aircraft Systems (UAS) and expanded MVNO (Mobile Virtual Network Operator) charging to cover satellite services and disaster roaming scenarios. Furthermore, the specifications were updated to clarify the converged charging refund mechanism for IEC (Immediate Event Charging) and to integrate the GMLC (Gateway Mobile Location Centre) into the 5GS charging architecture.
- Introduction of GMLC in charging architecture for 5GS TS 32.240CR0491
- Rel-19 CR 32.240 Add charging support to AIoT service TS 32.240CR0510
- Rel-19 CR 32.240 CAPIF Logical Charging Architecture TS 32.240CR0511
- Rel-19 CR 32.240 CAPIF Service Charging TS 32.240CR0512
- Add charging principles for UAS TS 32.240CR0517
- Add MVNO charging which provides satellite service TS 32.240CR0518
+ 6 more changes
Explore further
Broader topics and technologies where EBCF plays a role.
Defining Specifications
3GPP specifications that define or reference EBCF, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 32.240 vj40 | Charging Management Architecture & Principles | Rel-19 |
| TS 32.270 vj00 | MMS Charging Management Specification | Rel-19 |
| TS 32.272 vj00 | Charging for Push-to-Talk over Cellular (PoC) | Rel-19 |
| TS 32.278 vj00 | Monitoring Events Offline Charging Specification | Rel-19 |
| TS 32.296 vj00 | Online Charging System (OCS) Architecture | Rel-19 |
| TS 32.825 va00 | Study on Rc Reference Point for ABMF | Rel-10 |