Question: In a Fixed Broadband Access scenario, what information may the Policy and Charging Enforcement Function (PCEF) provide to the Online Charging System (OCS) for a fixed device behind a Residential Gateway (RG)?
Option 1: Only IMSI
Option 2: User name or Access line identifier, but not both
Option 3: User name, Access line identifier, and Access line id (physical and logical circuit ID)
Option 4: None of the above, as PCEF does not interact with OCS for fixed devices
Explanation: In Fixed Broadband Access for a device behind an RG, the PCEF may provide multiple identifiers to the OCS for accurate charging and policy enforcement. This includes a user name or Access line identifier for the device, as well as detailed Access line id (encompassing both physical and logical circuit IDs) when necessary, especially when identifying a 3GPP UE or a fixed device behind an RG. This comprehensive approach ensures precise billing and resource management.