In IEEE802.11 wireless local area networking standards(including Wi-Fi), a service set is a group of wireless network devices which share a service set identifier(SSID)----typically the natural language label that users see as a network name.
BSS is usually a Segment of memory used to store static variables in a program th at are not initialized globally.
In some common compliers, the usual way to deal with BSS segments is to descibe only the size, do not increase the size of the object file.
Because the variables are actually memory addresses, the complier normally sets variable addresses for variables that belong to the BSS segment, and the handling rules are not particularly different.
The task of zeroing out the BSS segment is usually done by the loader. When an executable file is loaded, the loader is responsible for zering out the BSS segment.
WiFi5 and previous standards usually adopt the mechanism of dynamic adjustment of CCA threshold to improve the interference between channels of the same frequency. By identifying the intensity of the interference of the same frequency, the CCA threshold is dynamically adjusted, and the weak interference signals of the same frequency are ignored to realize concurrent transmission of the same frequency, so as to improve the throughput capacity of the system.
WiFi6 introduces a new recognition mechanism of same-frequency transmission, named BSS Coloring mechanism. Add BSS color field to PHY header to "color" the data from different BSS, and assign one color to each channel. This color identifies a set of basic service sets (BSS) that should not be interfered with, so that the receiving end can recognize the interference signals of the same frequency transmission as early as possible and stop receiving, so as to avoid wasting the time of the transceiver. If the color is the same, it is considered to be the interference signal in the same BSS, and the transmission will be delayed. If the colors are different, it is considered that there is no interference between the two Wi-Fi devices, and the two Wi-Fi devices can transmit the signal in parallel with the same frequency.
There are several good custom WiFi 6 routers.
https://www.wallystech.com/Routerboard/DR6018V4-wifi6-Qualcomm-IPQ6010-IPQ6018-FAMILY-2T2R-2.5G-ETH-port-supporting-5G-celluar-Modem-802-11AX-MU-MIMO-OFDMA.html 
