1. A Policy and Charging Control (PCC) architecture (100), comprising:
an online charging system OCS (150) operable to store service-based tariffs that are associated
with service indicators for data services;
the OCS (150) is operable to receive a request for charging rules for an initial data service from
a Policy and Charging Rules Function PCRF (130), wherein the request includes a service
indicator for the initial data service;
the OCS (150) is further operable to identify a service-based tariff based on the service
indicator for the initial data service, to select between an online or offline charging method for
the initial data service based on the service-based tariff associated with the service indicator,
and to transmit a response to the PCRF (130) that includes the charging method selected for
the initial data service.
2. The PCC architecture (100) of claim 1 comprising:
the PCRF (130) operable to determine PCC rules for the initial data service based on the charging method selected by the OCS (150), and to transmit a response to a Policy and Charging Enforcement Function PCEF, (122) that includes the PCC rules for the initial data service, wherein the PCC rules include the charging method selected by the OCS (150); and the PCEF (122) operable to enforce the charging method selected by the OCS (150) on a service data flow for the initial data service.
3. The PCC architecture (100) as claimed in claim 1 wherein:
the OCS (150) is operable to receive a request for updated charging rules from the PCRF (130) responsive to a service change, wherein the request includes another service indicator for a new data service; and
the OCS (150) is operable to identify a service-based tariff based on the other service indicator for the new data service, to select between the online or offline charging method for the new data service based on the service-based tariff associated with the other service indicator, and to transmit a response to the PCRF (130) that includes the charging method selected for the new data service.
4. The PCC architecture (100) as claimed in claim 1 wherein:

the OCS (150) is operable to receive a charging request from a Policy and Charging Enforcement Function, PCEF, (122) responsive to a service change, wherein the charging request includes another service indicator for a new data service; and
the OCS (150) is operable to identify a service-based tariff based on the other service indicator for the new data service, to select between the online or offline charging method for the new data service based on the service-based tariff associated with the other service indicator, and to transmit a request to the PCRF (130) that includes the charging method selected for the new data service, wherein the request forces the PCRF (130) to update PCC rules based on the charging method for the new data service.
5. The PCC architecture as claimed in claim 4 wherein:
the OCS is operable to communicate with the PCRF over a Diameter Rx reference point; and the Diameter Rx reference point is expanded to include a new AVP for the charging method for the new data service.
6. The PCC architecture as claimed in claim 1 wherein:
the OCS is operable to communicate with the PCRF over a Diameter Sp reference point; and the Diameter Sp reference point is expanded to include a new AVP for the service indicator.
7. The PCC architecture as claimed in claim 6 wherein:
the Diameter Sp reference point is expanded to include a new AVP for the charging method for the initial data service.
8. A method of performing Policy and Charging Control (PCC), the method comprising:
storing service-based tariffs that are associated with service indicators for data services in an
online charging system (OCS);
receiving a request for charging rules for an initial data service in the OCS from a Policy and
Charging Rules Function (PCRF), wherein the request includes a service indicator for the initial
data service;
identifying a service-based tariff based on the service indicator for the initial data service;
selecting between an online or offline charging method for the initial data service in the OCS
based on the service-based tariff associated with the service indicator; and
transmitting a response from the OCS to the PCRF that includes the charging method selected
for the initial data service.

9. The method as claimed in claim 8 comprising:
determining PCC rules for the initial data service in the PCRF based on the charging method
selected by the OCS;
transmitting a response to a Policy and Charging Enforcement Function (PCEF) that includes
the PCC rules for the initial data service, where the PCC rules include the charging method
selected by the OCS; and
enforcing the charging method selected by the OCS on a service data flow for the initial data
service in the PCEF.
10. The method as claimed in claim 8 comprising:
receiving a request for updated charging rules in the OCS from the PCRF responsive to a service change, wherein the request includes another service indicator for a new data service; identifying a service-based tariff based on the other service indicator for the new data service; selecting between the online or offline charging method for the new data service in the OCS based on the service-based tariff associated with the other service indicator; and transmitting a response from the OCS to the PCRF' that includes the charging method selected for the new data service.
11. The method as claimed in claim 8 comprising:
receiving a charging request in the OCS from a Policy and Charging Enforcement Function (PCEF) responsive to a service change, wherein the charging request includes another service indicator for a new data service;
identifying a service-based tariff based on the other service indicator for the new data service; selecting between the online or offline charging method for the new data service in the OCS based on the service-based tariff associated with the other service indicator; and transmitting a request from the OCS to the PCRF that includes the charging method selected for the new data service, wherein the request forces the PCRF to update PCC rules based on the charging method for the new data service.
12. The method as claimed in claim 11 wherein:
the OCS communicates with the PCRF over a Diameter Rx reference point; and
the Diameter Rx reference point is expanded to include a new AVP for the charging method
for the new data service.

13. The method as claimed in claim 8 wherein:
the OCS communicates with the PCRF over a Diameter Sp reference point; and
the Diameter Sp reference point is expanded to include a new AVP for the service indicator.
14. The method as claimed in claim 13 wherein:
the Diameter Sp reference point is expanded to include a new AVP for the charging method for the initial data service.
15. An Online Charging System (OCS), comprising:
a Service Data Flow based Credit Control (SDFCC) function operable to perform online credit control functions; and
a Subscriber Profile and Service Control Management (SPSCM) function operable to store service-based tariffs that are associated with service indicators for data services, to receive a request for charging rules for an initial data service from a Policy and Charging Rules Function (PCRF), wherein the request includes a service indicator for the initial data service; the SPSCM function operable to identify a service-based tariff based on the service indicator for the initial data service, to select between an online or offline charging method for the initial data service based on the service-based tariff associated with the service indicator, and to transmit a response to the PCRF that includes the charging method selected for the initial data service.
16. The OCS as claimed in claim 15 wherein:
the SPSCM function is operable to receive a request for updated charging rules from the PCRF responsive to a service change, wherein the request for updated charging rules includes another service indicator for a new data service; and
the SPSCM function is operable to identify a service-based tariff based on the other service indicator for the new data service, to select between the online or offline charging method for the new data service based on the service-based tariff associated with the other service indicator, and to transmit a response to the PCRF that includes the charging method selected for the new data service.
17. The OCS as claimed in claim 15 wherein:
the SPSCM function is operable to receive a charging request from a Policy and Charging

Enforcement Function (PCEF) responsive to a service change, wherein the charging request includes another service indicator for a new data service; and
the SPSCM function is operable to identity a service-based tariff based on the other service indicator for the new data service, to select between the online or offline charging method for the new data service based on the service-based tariff associated with the other service indicator, and to transmit an update request to the PCRF that includes the charging method selected for the new data service, wherein the update request forces the PCRF to update PCC rules based on the charging method for the new data service.
18. The OCS as claimed in claim 17 wherein:
the update request comprises a Diameter Rx Authentication-Authorization-Request (AAR) that
includes an AVP defined for the charging method.