In this paper, we define a new performance parameter, named
, for 802.11 DCF, which binds successful transmission probability and saturation throughput together. An expression of optimal minimum contention windows (
is obtained analytically for maximizing PPT. For simplicity, we give a name DCF-PPT to the 802.11 DCF that sets its
according this expression. The simulation results indicate that, compared to 802.11 DCF, DCF-PPT can significantly increase the PPT and successful transmission probability (about 0.95) in condition that the saturation throughput is not decreased.