Question: What action does the transmitting side of an AM RLC entity take when the RETX_COUNT associated with an RLC SDU reaches maxRetxThreshold during retransmission?
Option 1: Increment RETX_COUNT and continue retransmitting
Option 2: Indicate to upper layers that max retransmission has been reached
Option 3: Reset RETX_COUNT to zero for another attempt
Option 4: Discard the RLC SDU without notifying upper layers
Explanation: According to the specified behavior for handling retransmissions in AM RLC entities, when the RETX_COUNT (retransmission count) associated with an RLC SDU reaches its maximum threshold (maxRetxThreshold), the entity is required to notify upper layers that the maximum number of retransmissions has been attained. This step is crucial for managing transmission failures and triggering potential higher-layer recovery mechanisms or error handling processes in wireless communication networks, such as those utilizing 5G NR (New Radio) technology.