Question: For a Multi-Standard Radio (MSR) Base Station (BS), when is the conducted emission test on the DC power input/output port specifically required?
Option 1: When the DC power cable is intended to be longer than 3 m, regardless of connection type.
Option 2: Only when the MSR BS is connected to a non-dedicated AC to DC power supply.
Option 3: For all configurations, irrespective of DC cable length or power supply type.
Option 4: When the MSR BS uses an external power adapter for AC to DC conversion.
Explanation: According to the 3GPP specification, the conducted emission test on the DC power input/output port is mandatory if the DC power cable of the radio equipment is intended to be longer than 3 meters. This ensures electromagnetic compatibility (EMC) for configurations where longer cables might introduce additional EMC risks. If the cable is less than 3 m and directly connected to a dedicated AC to DC power supply, the test focuses on the AC power input of that supply instead.