... and other characteristics can be measured, improved, and, to some extent, guaranteed in advance. ✔ QoS provides subscribers better reception for full-motion video, high-fidelity audio, and ... modifies the rules associated with DCF and PCF to create, respectively:✔ an Enhanced Distributed Channel Access Function (EDCAF) for DCF or DCF plus QoS ✔ And a Hybrid Coordination Function ... the Virtual Carrier-Sensing indicates the medium is idle and the station can transmit.● For the station to transmit both the physical and virtual carrier sense must report an idle condition...