Question: When an eNB (Evolved Node B) switches off a capacity booster cell to lower energy consumption, how are all peer eNBs informed about this switch-off action?
Option 1: Via the S1 interface using the MME Direct Information Transfer procedure
Option 2: Through the X2 interface using the eNB Configuration Update procedure
Option 3: By broadcasting a cell update message over the air interface to all nearby UEs (User Equipment)
Option 4: Manually by O&M (Operations and Maintenance) notification to each peer eNB
Explanation: When an eNB decides to switch off a capacity booster cell, it informs all peer eNBs about this action through the X2 interface. This is specifically done using the eNB Configuration Update procedure to ensure seamless network operation and coordination among eNBs, especially for handover and cell management purposes. This method ensures efficient communication between eNBs without relying on external entities like MME or broadcasting to UEs, which are not directly involved in this inter-eNB communication for cell status updates.