Question: In the context of Iur-g Successful Operation, what action does the DBSS (or DRNC) take upon receiving the DOWNLINK SIGNALLING TRANSFER REQUEST message containing a Cell Identifier (C-ID) and D-RNTI?
Option 1: The DBSS/DRNC sends L3 Information on SRB1 to the UE/MS in all cells within its coverage.
Option 2: The DBSS sends L3 Information on SRB2 (or DRNC on CCCH) to all UEs/MSs in the cell identified by the C-ID, regardless of D-RNTI.
Option 3: The DBSS/DRNC sends L3 Information on SRB2 (for DBSS) or CCCH (for DRNC) specifically to the UE/MS identified by the D-RNTI in the cell indicated by the C-ID.
Option 4: The DBSS/DRNC discards the message if the C-ID and D-RNTI do not match its stored identifiers for any UE/MS.
Explanation: This is the correct action as per the described procedure. The specificity of using SRB2 (for DBSS) or CCCH (for DRNC), targeting the UE/MS identified by the D-RNTI within the cell specified by the C-ID, ensures precise delivery of L3 Information. This targeted approach is crucial for efficient and secure communication in UTRAN networks, preventing unnecessary broadcasts and ensuring that only the intended UE/MS receives the information.