(10), but this time it represents the
probability that a single frame is transmitted in a slot, i.e., it does not contend with other
frames. Of course the frame will be successfully delivered only if it is transmitted alone in
a slot and it is not corrupted, i.e., with joint probability (1-?ΒΆ) Psuccess.
In Eq. (50), a new value Te is introduced to account for the duration of a period in
which no other stations can access the channel because a corrupted transmission is
occurring in the channel. A listening station which detects the transmitted frame as
corrupted will wait for an EIFS time interval. Thus:
Te = TMPDU + EIFS (51)
Note that some of the surrounding stations may correctly detect the frame. Hence, they
will be able to read the duration field in the MAC header of the transmitted frame, and set
the NAV accordingly. In other words, under the assumption that the ACK is transmitted at
1 Mbps, Te will result in the same value regardless of the fact that a listening station sees
the transmitted frame as a correct or corrupted one.
Performance Study of IEEE 802.11 DCF and IEEE 802.11e EDCA 86
4.4 MAC Enhancements for QoS Support
In this section, we present the 802.
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