Question: What is the primary purpose of the mechanism that allows the Home PLMN (HPLMN) to control when a User Equipment (UE) enters IDLE mode and initiates higher priority Public Land Mobile Network (PLMN) selection?
Option 1: To optimize network resource allocation
Option 2: To ensure seamless handover between different radio access technologies
Option 3: To prioritize emergency services over other communications
Option 4: To enable the HPLMN to control roaming behavior based on ongoing communication type
Explanation: The correct answer is Option 4 because the mechanism allows the HPLMN to control when a UE enters IDLE mode and initiates higher priority PLMN selection based on the type of ongoing communication, such as emergency calls or MPS sessions. This enables the HPLMN to manage roaming behavior and prioritize certain services over others.