Method and device for buffer status reporting

An UE for reporting a buffer status, the terminal comprising:

• a transceiver;
• and
• one or more processors coupled with the transceiver,
• wherein the processor is configured to:
• trigger a buffer status report (BSR) in a media access control (MAC) layer, based on a BSR triggering condition;
• transmit, to a base station, a scheduling request (SR) for transmitting uplink data;
• receive an uplink resource allocation grant (UL grant) from the base station, based on the SR;
• assemble a media access control protocol data unit (MAC PDU);
• transmit the MAC PDU;
• and
• determine whether to cancel the triggered BSR, based on a BSR MAC control element (BSR MAC CE) included in the MAC PDU.