Comment by throw0101a

3 hours ago

> only 1 transmitter at a time per channel - across all WLANs, yours and your neighbours, with no deterministic way to avoid collisions.

Not true with newer standards:

> Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user wireless transmission technology that divides a single Wi-Fi or cellular channel into smaller subcarriers called Resource Units (RUs), allowing multiple devices to transmit data simultaneously.

[…]

> Instead of one device occupying the entire channel (as in OFDM), OFDMA allows parallel transmissions. As a result, network congestion decreases significantly.

* https://www.netcomlearning.com/blog/what-is-ofdma

* https://airheads.hpe.com/blogs/antar1/2020/10/19/why-is-ofdm...

> In addition, the 802.11ax standard defines the smallest subchannel as a resource unit (RU), which includes at least 26 subcarriers and uniquely identifies a user. The resources of the entire channel are divided into small RUs with fixed sizes. In this mode, user data is carried on each RU. Therefore, on the total time-frequency resources, multiple users may simultaneously send data in each time segment, as shown in the following figure.

* https://info.support.huawei.com/info-finder/encyclopedia/en/...

* https://blogs.cisco.com/networking/wi-fi-6-ofdma-resource-un...

With a 26-Tone RU Type, nine devices can operate simultaneous in even a 20 MHz channel (eighteen in 40 MHz, etc); see Figures 2 and 3: