Siemens IEEE802.11 - Manual (Page 34)

, © Siemens, 2002
Tx Data to STA 2
Rx data from STA 1
Detects channel busy
Station 1
Station 2
Station 3
Station 4
Short deferral
Distributed inter-frame deferral
Distributed inter-frame deferral
Distributed inter-
frame deferral
Distributed inter-
frame deferral
Random back-off
Random back-off
ACK to STA1
Short interval ensures ACK is
sent while other stations wait
longer
Tx Data
STA 3’s back-off is shorter than
STA 4’s therefore it begins
transmission first
'HWHFWV FKDQQHO EXV\
'HWHFWV FKDQQHO EXV\
Detects channel busy
'HWHFWV FKDQQHO EXV\
Distributed Coordination Function (DCF)