Question: In a 5G System roaming architecture with local breakout, what is the primary purpose of the Charging Function (CHF) in the Home Public Land Mobile Network (HPLMN)?
Option 1: To collect charging information for wholesale billing towards the Visited Public Land Mobile Network (VPLMN)
Option 2: To perform retail charging towards the home subscriber while roaming
Option 3: To manage control plane signaling for inbound roamers
Option 4: To handle user plane traffic for outbound roamers
Explanation: In a 5G roaming architecture with local breakout, the CHF in the HPLMN is responsible for processing charging information to bill the home subscriber for services used while roaming. This is an example of retail charging, where the HPLMN directly charges its own subscribers for roaming services, as opposed to wholesale charging which involves billing between networks (e.g., VPLMN to HPLMN).