Question: During an intra LTE S1 handover, what is primarily transferred between the source and target eNodeB (eNB) via the Mobility Management Entity (MME) for each affected Evolved Radio Access Bearer (E-RAB)?
Option 1: Only Uplink Packet Data Convergence Protocol Sequence Number (PDCP-SN) and Hyper Frame Number (HFN) receiver status.
Option 2: Only Downlink PDCP-SN and HFN transmitter status.
Option 3: Radio Resource Control (RRC) configuration parameters.
Option 4: Both Uplink & Downlink PDCP-SN and HFN statuses (receiver for uplink, transmitter for downlink).
Explanation: This is correct because the eNB Status Transfer procedure aims to preserve the continuity of data transmission during handovers. To achieve this, both the uplink (receiver) and downlink (transmitter) PDCP Sequence Numbers (PDCP-SN) and Hyper Frame Numbers (HFN) are crucial for maintaining sequence integrity in both directions, ensuring seamless communication across the handover for each relevant E-RAB.