Wi-Fi, TDM how does it work?

Question

WiFi

Let's take an access point with MIMO 1x1:1
For example, there are 8 clients in the network. Each client sends data to a point. With what maximum delay will a packet from the client arrive at the point?
I'm interested in the following:
1) I'm not good at this, so please point out where I'm wrong: the channel is divided into 9 timeslots (8 time slots are sent from clients and 1 from the access point itself). Thus, the data from the last client in the queue will arrive in 9*(timeslot length). Is everything right?
2) What is the length of the timeslot for WIFI?
3) Is it possible to change the timeslot length (in openwrt)?
3) Let's say they replaced the AP with another one, with MIMO 2x2: 2. I understand the delays will remain the same?
Z.Y. We consider the case spherical in vacuum. There is no interference.

Answer 1

The channel is not divided into timeslots. Each station, in this case the client, listens on the medium to determine if it is busy or not. As soon as the station determines that the medium is free, then it must maintain a certain interframe interval (IFS). I don't remember how long it was, unfortunately. If after that the environment is still free, then the countdown of timeslots begins. The timeslot length is fixed and depends on how the signal is coded, such as FHSS or DSSS. https://en.wikipedia.org/wiki/Spread_spectrum
For the first method, this is 28 µs, and for the second, it seems to be 1 µs, I can’t say for sure.
Then, a timeslot number is randomly selected in the range from 0 to the size of the competitive window. At the beginning of each slot, the employment of the environment is also checked again. Well, if it is free, then the frame is transmitted accordingly. Therefore, when calculating the time of arrival of data from the last station, it is also necessary to take into account at least the interframe interval, and the fact that the timeslot is chosen randomly. Well, plus all sorts of interference, the frame will not reach, for example, it will be re-sent, etc. That's all for DCF mode. There is also for PCF priority traffic, everything is slightly different there. There are 3 types of interframe intervals used.
In theory, depending on the physical layer (abgn ac), the timeslot length will decrease with increasing transmission speed.
According to wiki.openwrt.org/doc/uci/wirelesstimeslot length can only be changed for hardware with a broadcom chip.
When changing the access point, delays may decrease, but not a fact. It also depends on the client's equipment, I think.