The radio transceiver supports data rates of {500,1000, 2000} kb/s during the PSDU part of the frame, which are not compinat to IEEE 802.15.4 standard. This reduces the utilization time of the air interface at the expense of a decreased receiver sensitivity. Since information on the data rate itself is not conveyed, the target data rate mode needs to be set up front at both, transmitting and receiving node. For more details refer to section 11.3(High Data Rate Modes) of the AT86RF231 datasheet.
Note:
When using the high data rate mode, no LQI value is appended during the frame read procedure. Instead, the ED value is appended.