Question: How are RRC PDUs mapped to/from PDCP SDUs for transmission/reception in case of Dedicated Control Channel (DCCH)?
Option 1: The last bit of the RRC PDU is represented as the first bit in the PDCP SDU.
Option 2: The RRC PDU is encoded into multiple PDCP SDUs with no specific bit alignment.
Option 3: The first bit of the RRC PDU is represented as the first bit in the PDCP SDU, and onwards.
Option 4: The mapping depends on the UE's (User Equipment) capabilities, varying the bit representation.
Explanation: In the context of Dedicated Control Channel (DCCH), RRC PDUs are mapped to/from PDCP SDUs with a specific alignment for efficient transmission and reception. The correct approach is that the first bit of the RRC PDU directly corresponds to the first bit in the PDCP SDU, ensuring seamless communication between layers. This direct mapping facilitates accurate decoding and interpretation of control messages at the receiving end.