Question: What triggers the measurement of the number of attempted WLAN additions to the LWA WLAN mobility set?
Option 1: Transmission of RRCConnectionReconfiguration message which includes the wlan-ToAddList in the lwa-MobilityConfig of lwa-Configuration information element by the eNB.
Option 2: Receipt of a specific packet from the UE.
Option 3: Periodic timer expiration.
Option 4: Handover procedure initiation.
Explanation: The measurement is triggered when the eNB transmits an RRCConnectionReconfiguration message that includes the wlan-ToAddList in the lwa-MobilityConfig of lwa-Configuration information element, as specified in TS 36.331. This event indicates an attempt to add a WLAN to the LWA WLAN mobility set.