WiFi6 - BSS coloring

A 6-bit identifier is added to the packet header to differentiate between BSSs of APs on the same channel. In this way, when an AP receives a packet destined for another AP, the AP can discard the packet to avoid a conflict by only decapsulating a physical preamble, instead of decapsulating the entire packet as in existing solutions. BSS coloring enables more orderly and certain use of channel resources, and can boost a sharp improvement to overall system performance in high-density environments.
In the preceding metaphorical example, such practice is equivalent to dividing one lane into mutually independent underpass and overpass lanes in space and dispatching vehicles to the lanes according to transmission destinations, for effective spatial reuse.