A DECT base station for transmitting a data frame, wherein the DECT base station comprises a first codec module and a first RF module; the first codec module is configured to store an acquired encoded data frame in an encoding buffer area of the first codec module; wherein, between a length of the encoded data frame and a length of a B-field data in a TDMA frame, there is a multiple relationship; and when receiving a first trigger signal, the first RF module is configured to extract the encoded data frame acquired by the first codec module from the encoding buffer area and fill the extracted encoded data frame into a B-field of a corresponding slot in the TDMA frame and send the encoded data frame to a mobile terminal; wherein the first trigger signal is set synchronized with the TDMA frame from the first RF module for guaranteeing that the B-field data of the corresponding time slot in the TDMA frame sent by the first RF module to the mobile terminal is consistent with the acquired encoded data frame from the first codec module; when receiving a second trigger signal, the first RF module is configured to extract a data fame to be decoded from the TDMA frame sent by the mobile terminal and send the extracted data frame to be decoded to the first codec module; wherein the second trigger signal is set synchronized with a TDMA frame acquired by the first RF module for guaranteeing that the data frame to be decoded sent by the first RF module to the first codec module is consistent with a B-field data of a corresponding time slot in the TDMA frame from the mobile terminal acquired by the first RF module; wherein, between a length of the data frame to be decoded and a length of a B-field data in the TDMA frame, there is a multiple relationship; and the first codec module is further configured to store the data frame to be decoded in a decoding buffer area of the first codec module to decode the data frame to be decoded; the first trigger signal is any time slot in the TDMA frame; the second trigger signal is any time slot in the TDMA frame. the first codec module is configured to store an acquired encoded data frame in an encoding buffer area of the first codec module; wherein, between a length of the encoded data frame and a length of a B-field data in a TDMA frame, there is a multiple relationship; and when receiving a first trigger signal, the first RF module is configured to extract the encoded data frame acquired by the first codec module from the encoding buffer area and fill the extracted encoded data frame into a B-field of a corresponding slot in the TDMA frame and send the encoded data frame to a mobile terminal; wherein the first trigger signal is set synchronized with the TDMA frame from the first RF module for guaranteeing that the B-field data of the corresponding time slot in the TDMA frame sent by the first RF module to the mobile terminal is consistent with the acquired encoded data frame from the first codec module; when receiving a second trigger signal, the first RF module is configured to extract a data fame to be decoded from the TDMA frame sent by the mobile terminal and send the extracted data frame to be decoded to the first codec module; wherein the second trigger signal is set synchronized with a TDMA frame acquired by the first RF module for guaranteeing that the data frame to be decoded sent by the first RF module to the first codec module is consistent with a B-field data of a corresponding time slot in the TDMA frame from the mobile terminal acquired by the first RF module; wherein, between a length of the data frame to be decoded and a length of a B-field data in the TDMA frame, there is a multiple relationship; and the first codec module is further configured to store the data frame to be decoded in a decoding buffer area of the first codec module to decode the data frame to be decoded; the first trigger signal is any time slot in the TDMA frame; the second trigger signal is any time slot in the TDMA frame.