Thomas Kunz
Systems and Computer Engineering
174
802.11 MAC: RTS/CTS
nSending unicast packets
–station can
send RTS with reservation parameter after waiting for DIFS (reservation determines amount of time the data
packet needs the medium)
–acknowledgement
via CTS after SIFS by receiver (if ready to receive)
–sender can
now send data at once, acknowledgement via ACK
–other
stations store medium reservations distributed via RTS and CTS
t
SIFS
DIFS
data
ACK
defer access
other
stations
receiver
sender
data
DIFS
contention
RTS
CTS
SIFS
SIFS
NAV (RTS)
NAV (CTS)