Question: During an Inter-MSC Handover, where is the indication of the chosen encryption algorithm sent if ciphering was performed before the handover?
Option 1: In the Cipher Mode Command procedure between MSC-A and MSC-B
Option 2: In the Handover Request Acknowledge message from BSS to MSC-B
Option 3: In the Assignment Complete message from BSS to MSC-A
Option 4: In the Handover Performed procedure initiated by MSC-B after intra-MSC handover
Explanation: According to encryption information transfer rules during Inter-MSC Handover, if ciphering has been performed before the handover, the chosen algorithm's indication is included in the Handover Request and acknowledged with the chosen algorithm in the Handover Request Acknowledge, ensuring seamless continuation of the established security context.