Abstract: IEEE 802. 11e EDCA mechanism permits using CFB (Contention Free Burst) , which will control the media in a whole TXOP. So it can save some time to occupy the channel and improve the QoS. But few papers think over TXOP in non-saturation. This paper proposed an easy analysis model of TC;P/UDP heterogeneous flows appear in non-saturated condition based on IEEE 802. lle EDCA mechanism the model thinks over CFB, the simulation results indicate that the model is valid on forecasting the EI}CA mechanism of mixed flows, and the interaction of the mixed TCP/UDP flows appear when they share the same channel.

Key words: Heterogeneous flows, EDCA, QoS, Non-saturation, CFB