Question: Upon receiving a NACK on the Acquisition Indication Channel (AICH), what is the immediate action taken by the User Equipment (UE) regarding preamble transmission, followed by its next step after the expiration of timer TB01?
Option 1: Continue transmitting preambles at an increased rate and then repeat the ramping procedure when TB01 expires.
Option 2: Stop transmitting preambles immediately, wait for TB01 to expire, and then initiate a new random access attempt without repeating the ramping procedure.
Option 3: Stop transmitting preambles immediately and then repeat the ramping procedure from the start (including the first step) after TB01 expires.
Option 4: Reduce preamble transmission power and continue transmitting until TB01 expires, then restart the ramping cycle.
Explanation: Upon receiving a NACK on the AICH, the UE must immediately cease transmitting preambles. After the backoff timer (TB01) expires, the UE repeats the ramping procedure from the start, ensuring alignment with network access protocols for efficient and orderly connection establishment, minimizing potential congestion and optimizing network resource allocation.