Question: What action does a User Equipment (UE) take when receiving a PDCP Control PDU for an interspersed ROHC (Robust Header Compression) feedback packet from lower layers in an E-UTRA network?
Option 1: The UE deciphers the packet before delivering it to the associated header compression protocol.
Option 2: The UE discards the packet if it's not decipherable, then notifies the network.
Option 3: The UE delivers the corresponding interspersed ROHC feedback packet to the associated header compression protocol without performing deciphering.
Option 4: The UE buffers the packet until a predetermined threshold of similar packets is reached before processing.
Explanation: In E-UTRA networks, for efficient use of resources and to maintain integrity, specific protocols like ROHC are used for header compression. When the UE receives a PDCP Control PDU indicating an interspersed ROHC feedback packet, it's designed to handle this efficiently by directly passing on the necessary information to the relevant protocol (associated header compression protocol) without the need for deciphering, which would otherwise add latency and computational overhead. This approach ensures seamless and efficient communication, highlighting the importance of streamlined processing in telecom networks.