Question: How does the BAP sublayer route backhaul traffic in EN-DC and NR-DC?
Option 1: The BAP sublayer routes backhaul traffic via both LTE and NR interfaces.
Option 2: The BAP sublayer routes backhaul traffic via only the LTE interface.
Option 3: The BAP sublayer routes backhaul traffic via a single IAB-node.
Option 4: In EN-DC, the BAP sublayer routes backhaul traffic via only the NR interface, while in NR-DC, it can route via two NR interfaces to the same IAB-donor.
Explanation: The correct answer is Option 4 because in EN-DC, the BAP sublayer is configured to route backhaul traffic solely through the NR interface. In contrast, NR-DC allows for more flexibility by enabling the BAP sublayer to distribute backhaul traffic across two separate NR interfaces that connect to the same IAB-donor, thereby enhancing network efficiency and reliability.