Question: In a RANflex configuration with group call redundancy for Voice Group Call Service (VGCS), what information is included in the GCR interrogation negative response when indicating an 'on-going call'?
Option 1: MSC address of the MSC within the redundancy pool where the group call is ongoing
Option 2: IMSI of the users currently participating in the group call
Option 3: Cell ID where the group call was initiated
Option 4: Timestamp of when the group call started
Explanation: In a RANflex configuration with group call redundancy for VGCS, knowing which MSC within the pool is handling an ongoing group call is crucial for efficient call management and routing decisions. Including the MSC address in the negative response facilitates this by providing essential location information for the ongoing call, thus enabling proper handling of subsequent requests or operations related to that call.