Question: In UTRAN Iur interface RNSAP signalling, upon receiving a DOWNLINK SIGNALLING TRANSFER REQUEST with "not Release D-RNTI" set for an already accessed cell under a different controller, how should the DRNC/DBSS proceed with the D-RNTI?
Option 1: Ignore the IE and release the D-RNTI to maintain resource consistency across controllers.
Option 2: Honor the "not Release D-RNTI" indication to avoid disrupting ongoing sessions.
Option 3: Request further clarification from the SBSS/SRNC before taking any action on the D-RNTI.
Option 4: Reject the DOWNLINK SIGNALLING TRANSFER REQUEST entirely due to the conflicting controller situation.
Explanation: To ensure seamless network operation and resource management, when a user's device is already connected to another cell under a different DRNC/DBSS, releasing the D-RNTI upon receiving a DOWNLINK SIGNALLING TRANSFER REQUEST with "not Release D-RNTI" set prevents potential conflicts or duplicate allocations. This approach aligns with maintaining network efficiency and preventing resource inconsistencies across different controllers in UTRAN architectures.