[Make-wifi-fast] Looking for a citation...

[Sebastian Moeller]

Hi Rich,


> On 18. Aug 2024, at 11:08, Rich Brown via Make-wifi-fast <make-wifi-fast at lists.bufferbloat.net> wrote:
> 
> In various posts, I have baldly asserted that "above 300-500mbps ISP links, all the bufferbloat moves into the Wi-Fi." 
> 
> I am pretty sure that I someone on these lists stated that as fact.

[SM] This is somewhat hard to assess, as most WiFi gear likely lives in home networks (and is not replaced routinely*) and does not give any upstream feedback about which MCS and number of streams are typically achievable. Operators of  managed WIFi networks should know, but I guess for those this is pretty intimate information that they might not want to share with the competitors.

But a rule of thumb is that achievable throughput for WiFi is closer to 50% of the MCS table rate (see https://mcsindex.com/), I would guess that the bulk of existing stations will have >= 3 antennas and will be pre-802.11.ax, but that still leaves guessing the channel width... but if we assume 80 MHz channels (anecdotally based on looking around in my WiFi surround) the highest likely MCS rate would be 1170, which gets us to the upper end of you estimate once we account for the 50% utilisation factor... But given the amount of assumptions we had to make, I am not sure that offers the certainty you are after...

*) I expect wildly different update schedules for routers/APs, notebooks, and mobile devices. Smartphones might on the forefront with some folks replacing them every 24 months, and laptops/APs on much slower schedules.... so even if WiFi6/7 gear starts hitting some customer premises, I expect a looooong tail of WiFi4/5 devices


> Could I get a link to a discussion that is definitive? Or a statement that is actually true that I can incorporate into my future posts? Many thanks.
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