Question: In an LTE-WLAN Aggregation (LWA) setup, where does an LWAAP entity receive/deliver LWAAP SDUs from/to, in relation to the protocol stack?
Option 1: Directly from/to the RRC layer for configuration and control
Option 2: From/to lower layers (e.g., MAC) for transmission over WLAN
Option 3: From/to the IP layer for routing decisions
Option 4: From/to upper layers (i.e., PDCP) as part of the data forwarding process
Explanation: This is correct because, according to the LWAAP specification, an LWAAP entity interacts with upper layers (specifically, the PDCP layer) for receiving and delivering LWAAP SDUs. This interaction is crucial for the proper forwarding of data in an LWA setup, ensuring that data is correctly encapsulated into LWAAP PDUs for transmission over WLAN or reassembled from received LWAAP PDUs.