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| n |
Sense
media before transmission
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| n |
If
media is free, transmit if media stays idle for a fixed amount of time
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(DCF
Interframe Space, DIFS)
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| n |
Defer:
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– |
wait
until end of current transmission, plus DIFS
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– |
apply
random backoff procedure: pick number between 0 and 7, check
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whether
medium is idle during each backoff slot
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– |
if
media is busy, suspend backoff process at beginning of current slot
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– |
after
media was idle for selected number of slots, transmit immediately
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– |
if
this transmission results in collision, backoff again, doubling the backoff
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| n |
Upon
receipt of packet:
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– |
receiver
waits short interval (Short Interframe Space, SIFS)
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– |
transmits
acknowledgement frame (ACK) back to sender
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| n |
If
sender receives no ACK within ACKTimeout interval, assume
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collision
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