Question: In an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), what is the primary purpose of the "eNB EARLY STATUS TRANSFER" message sent from the source eNodeB (eNB) to the Mobility Management Entity (MME)?
Option 1: To initiate a S1 handover procedure based on geographical location triggers.
Option 2: To transfer user data during an ongoing S1 DAPS Handover or time-based trigger condition handover.
Option 3: To request resource allocation for upcoming downlink transmissions from the MME.
Option 4: To convey the COUNT value(s) of the first forwarded downlink Service Data Unit(s) (SDU(s)) during specific handover scenarios.
Explanation: The correct answer, Option 4, accurately reflects the primary purpose of the "eNB EARLY STATUS TRANSFER" message as defined in the context of E-UTRAN's S1 Application Protocol. This message is specifically used to transfer COUNT values related to the first forwarded downlink SDUs during handovers triggered by either S1 DAPS or time-based conditions, ensuring seamless communication continuity. The other options misrepresent the message's purpose, focusing on initiation, data transfer, and resource allocation, which are not its primary functions in this context.