Question: Which interface is utilized by the MC-IOPS-5 reference point for obtaining unicast bearers with appropriate QoS from the IOPS EPS in Mission Critical Services support?
Option 1: S1 Interface (between eNodeB and MME)
Option 2: Rx Interface (of the EPS, for Policy and Charging Control)
Option 3: S6a Interface (between MME and HSS)
Option 4: Gx Interface (between PCEF and PCRF)
Explanation: The MC-IOPS-5 reference point, designed for Mission Critical Services in Isolated Operation for Public Safety (IOPS) mode, leverages the Rx interface. This interface, part of the EPS's Policy and Charging Control architecture, enables obtaining unicast bearers with suitable Quality of Service (QoS) from the IOPS EPS, facilitating policy and charging decisions for public safety services' critical communication requirements.