Question: What triggers the measurement of attempted WLAN additions to the LWIP WLAN mobility set in an E-UTRAN network?
Option 1: Transmission of RRCConnectionReconfiguration message by the UE.
Option 2: Receipt of wlan-ToAddList in the lwip-MobilityConfig of lwip-Configuration information element by the eNB from the MME.
Option 3: Successful addition of a WLAN to the LWIP WLAN mobility set.
Option 4: Transmission of RRCConnectionReconfiguration message which includes the wlan-ToAddList in the lwip-MobilityConfig of lwip-Configuration information element by the eNB.
Explanation: The measurement is triggered when the eNB transmits an RRCConnectionReconfiguration message that includes the wlan-ToAddList in the lwip-MobilityConfig of lwip-Configuration information element, indicating an attempt to add a WLAN to the LWIP WLAN mobility set.