Question: What is a mandatory requirement for all User Equipment (UE) regarding the support of measurement channels?
Option 1: All UEs must support all measurement channels for both up- and downlink, regardless of their Radio Access capabilities.
Option 2: Any UE must support at least the 12.2 kbps measurement channel in both up- and downlink directions.
Option 3: Support for any measurement channel is entirely optional and depends on the UE's manufacturer choice.
Option 4: UEs are required to support all measurement channels except for the 12.2 kbps channel, which is optional.
Explanation: According to the specifications, while support for other measurement channels may vary based on a UE's Radio Access capabilities, there is a specific requirement that any UE must support the 12.2 kbps measurement channel in both up- and downlink directions, ensuring a baseline level of compatibility across all devices.