Question: During Intra E-UTRAN Mobility (handover), how are the Hyper Frame Number (HFN) and PDCP Sequence Number (SN) handled for Radio Link Control (RLC)-Acknowledged Mode (AM) bearers?
Option 1: HFN and PDCP SN are maintained to ensure continuous data transmission.
Option 2: HFN is reset, but PDCP SN is maintained for seamless handover.
Option 3: Both HFN and PDCP SN are reset to synchronize with the target eNB.
Option 4: The handling depends on the UE's capability, which is signaled during attachment.
Explanation: Maintaining both the Hyper Frame Number (HFN) and PDCP Sequence Number (SN) for RLC-AM bearers during handover ensures that data transmission remains continuous and in sequence, preventing potential errors or losses that could occur with resets. This approach supports the seamless mobility required in E-UTRAN networks.