Question: In a Voice Group Call Service (VGCS), what triggers the Base Station Controller (BSC) to send a VGCS ASSIGNMENT_STATUS message to the Mobile Switching Center (MSC), which in turn helps the MSC determine call setup conditions?
Option 1: Expiration of Timer Tast without any changes in group call area cells.
Option 2: Establishment of channels to all cells for a given group call area served by the BSC.
Option 3: Receipt of VGCS ASSIGNMENT REQUEST message from MSC.
Option 4: Release of a channel in one of the group call area cells.
Explanation: The correct answer is Option 2 because, once all cells for a given group call area served by a BSC are established, this BSC sends a VGCS ASSIGNMENT_STATUS message to the MSC. This message is crucial for the MSC to assess conditions necessary for setting up the call, highlighting the importance of synchronization and status updates between network elements in managing group calls efficiently.