Summary

We have seen the formats of the IEEE 802.11 MAC sub-layer Control, Management (MMPDU), and Data (MPDU) frames, and enumerated all possible combinations of headers, taking into consideration IEEE 802.11e and IEEE 802.11i, as well as IEEE 802.1Q-2003 VLANs. We have described the structure of the FC field, the first two octets of every type of IEEE 802.11 MAC sub-layer protocol frame, which defines the structure and format of the frame that follows. We have compared the usage of IEEE 802.1Q-2003 VLANs in IEEE 802.11 against their usage in Ethernet. We have differentiated the characteristics of IBSS (ad hoc) vs. infrastructure WLANs. We have related the MSDU to the MPDU, and compared the MSDU/MPDU relationship to the PSDU/PPDU relationship at the PLCP layer.