Question: In a scenario where the Packet Control Unit (PCU) is remotely located from the Base Transceiver Station (BTS), what mechanism is utilized for inband signaling to facilitate control between the Channel Codec Unit (CCU) in the BTS and the remote PCU in the Base Station Controller (BSC)?
Option 1: Dedicated Signaling Channel
Option 2: Out-of-Band Signaling Protocol
Option 3: Shared Radio Resource
Option 4: Control Bits (C-bits) in each PCU Frame
Explanation: In the context of a remote Packet Control Unit (PCU), efficient communication between the PCU and the Channel Codec Unit (CCU) in the Base Transceiver Station (BTS) is crucial. The use of control bits (C-bits) within each PCU frame for inband signaling allows for necessary control, enabling the CCU to manage certain functions in the remote PCU and vice versa, without dedicating additional resources or relying on out-of-band mechanisms, optimizing existing communication channels for both data and control signaling.