Basic Service SetColoring, BSS Coloring, is a procedure with which the basic services (BSS) can be assigned separately and without overlapping influences. The procedure has already been introduced in WLANs according to 802.11ah and assigns a different color to each BSS service.
With basic service sets, the aim is to achieve a clear distinction between the services and to ensure that the WLAN devices access the correct BSS service. For this reason, BSS coloring gives each Basic Service Set a number, which is declared as a color. This number is added to the PHY header and the channel is assigned only when the number is recognized. After assignment, the channel is marked as busy with a special bit.