Re: Max bit rates

On Mon, Feb 10, 2020 at 02:32:06PM -0800, Matthew Wang wrote:
> The estimated throughput calculation done in wpa_supplicant/scan.c is
> based on a step function that maps SNR to a bitrate [0]. As I
> understand it, these bitrates come from something like mcsindex.com
> that maps an MCS index to the corresponding maximum bitrate. My
> question is this: where do the SNR to MCS index mappings come from,
> and why do they differ from another table I have found [1]?
> 
> [0] https://w1.fi/cgit/hostap/commit/wpa_supplicant/scan.c?id=a1b790eb9d75
> [1] https://d2cpnw0u24fjm4.cloudfront.net/wp-content/uploads/80211-Data-rates-and-snr-requriements-screen-shot.png

This is from five years ago and unfortunately I could not easily find my
notes for that and I don't remember the details. I think I used two
different tables (one for the legacy rates and another one for the
HT/VHT MCS values) and calculated the SNR values based on the tables
showing minimum RSSI.

-- 
Jouni Malinen                                            PGP id EFC895FA