AT commands are used for controlling Mobile Termination (MT) functions and GSM/UMTS network services from a Terminal Equipment (TE) through Terminal Adaptor (TA). 3GPP introduces multiple backoff timers and barring to solve network congestion problem. However, a TE does not know the timer value and the barring status. In accordance with one novel aspect, a new AT command interface that can respond timer value and barring status to the TE is proposed. It reduces wasteful retries and saves power consumption of the TE. Through the new AT command interface, the TE can query backoff timer status. Via unsolicited result code (URC), the MT can detect backoff timer status change and report updated backoff timer status to the TE.