Question: In a 3GPP-compliant Policy and Charging Control (PCC) architecture, which of the following statements about supported charging models is INCORRECT for both PCEF (Policy and Charging Enforcement Function) and TDF (Traffic Detection Function)?
Option 1: Volume based charging is supported for all services.
Option 2: Event based charging can be applied to non-session based charging scenarios.
Option 3: A combination of volume and time based charging models can be used.
Option 4: No charging implies that the service is free for all parties involved, including third-party service providers.
Explanation: According to the 3GPP TS specifications, Event based charging (as defined in this context) applies only to session-based charging. This means Option 2 is incorrect because it suggests Event based charging can be applied more broadly than specified, to non-session based charging scenarios. The other options align with the supported charging models and their potential combinations or implications within a PCC architecture.