Question: In E-UTRA Radio Link Control (RLC) protocol, what does the Segment Offset (SO) field indicate for an AMD PDU segment, and how is its starting point referenced?
Option 1: The total length of the AMD PDU in bytes, with the first byte referenced by SO value "1"
Option 2: The position of the last byte of the segment within the original AMD PDU, with numbering starting at "1"
Option 3: The type of data carried in the AMD PDU segment, with specific values for control and user plane data
Option 4: The position of the first byte of the segment's Data field within the original AMD PDU's Data field, with the first byte referenced by an SO value indicating a start at zero
Explanation: The Segment Offset (SO) field indicates where within the original AMD PDU's Data field the first byte of the segment's Data field is located, using a zero-based indexing system, crucial for correctly reassembling segmented PDUs at the receiving end in E-UTRA RLC protocol.