Question: What is distinct about the handling of EHC (Efficient Header Compression) feedback packets in relation to PDCP (Packet Data Convergence Protocol) processing?
Option 1: EHC feedback packets are always associated with a new, incremented PDCP Sequence Number (SN).
Option 2: EHC feedback packets are not associated with a PDCP SDU, PDCP SN, and are not ciphered/integrity protected.
Option 3: EHC feedback packets undergo the same header compression as EHC compressed packets but without a COUNT value.
Option 4: EHC feedback packets are used to request retransmission of lost PDCP SDUs and thus carry a specific PDCP SN.
Explanation: This is correct because, according to the specifications, EHC feedback packets stand alone, not associated with any PDCP Service Data Unit (SDU), and as such, they do not carry a PDCP Sequence Number (SN) nor are they subjected to ciphering or integrity protection, distinguishing them from EHC compressed packets which are tied to specific PDCP SDUs.