Ch 7 802.11 Mac Operation Flashcards
Blank are associated with the mac sublayer of the data-link layer (layer 2) in the OSI model.
The MSDU (MAC Service Data Unit) and MPDU (MAC Protocol Unit)
Blank are associated with the physical layer (layer 1) of the OST model.
The PSDU (Physical Layer Data Unit) and PPDU (Physical Layer Protocol Data Unit)
The guard interval (gi) is a space of time between blank within in 802.11 frames.
symbols
The short gi is 400 ns and the long gi is 800 ns.
Short 400 and long 800
interframe spaces (ifs) are used
between frames.
SIFS (Short Interframe spaces) is always
before ack frames.
DIFS is used before non-QoS data frames
non-QoS data frames
AIFS is used before blank
QoS data frames.
blank may be fragmented before transmission to reduce the likelihood of interference with the transmission.
Frames
The blank amendment provides a single phy header that is compatible with all other 5 GHz Phys (both ht and OFDM).
802.11ac
The 802.11 general frame format includes blank
a header, data payload (when required) and frame check sequence (FCS).
Blank are transmitted by APs to announce the presence of a BSS and the parameters of that BSS.
Beacon frames
Blank frames are used in the active scanning process.
Probe request and probe response
Blank frames are used to associate with an AP and move to state 3 of the 802.11 state machine.
Association request and Association response
Blank are used for open system authentication with the AP.
Authentication frames
