Question: During a handover from UMTS to GSM, where is the BSSMAP Service Handover information transferred to the 3G_MSC-B from, and how is it subsequently sent?
Option 1: Transferred in Prepare Handover Request MAP message and sent to BSS in Handover Request BSSMAP message.
Option 2: Transferred in Handover Request BSSMAP message and sent to RNS in Relocation Request.
Option 3: Transferred in Forward Access Signalling Request MAP message and sent to BSS in Assignment Procedure.
Option 4: Not applicable for UMTS to GSM handovers.
Explanation: When performing a handover from UMTS (3G) to GSM, the BSSMAP Service Handover information is specifically related to the GSM side. Thus, it is transferred to the 3G_MSC-B in the context of preparing for a GSM handover, which aligns with receiving such information in a Prepare Handover Request. Subsequently, when 3G_MSC-B performs the handover to GSM, it sends this information to a BSS in a Handover Request BSSMAP message, as per standard GSM handover procedures.