Description: A switch flag, which set the short preamble status as enable or disable, tells whether the short preamble is supported by the radio. Enable means the radio supports short preamble, disable means the radio doesn't support short preamble. Preamble, which is used to identify synchronization and the data packet that immediately follows, is a set of bits in the front of a data packet by receiver. It recommends to use short preamble, because it can make the synchronous performance of the network well. Preamble includes short preamble and normal preamble, the normal preamble usually is used at the scene compatible with some old kind of client network Adapter.