The 802.11 standard defines classes of frames for use in transmission of data, control, and management. A data frame has the following fields: frame control, duration, address (1~3), sequence, data, check sequence. The frame control field is made up of 11 subfields, which contain version bits, frame type bits, distribution system bits, and so on. The duration field tells the channel occupancy time. The address fields indicate the receiver, the transmitter, and the distant endpoint address. The sequence field identifies the fragment number and next frame number. The data field contains the payload, whose first bytes are LLC. The check sequence field is the 32-bit CRC.
