These values were defined in upstream commit a1b790eb9d7514d1a6e0582a07f695a1564caa59 with no justification. Other sources [0,1,2] give a different (consistent) set of SNR floors per MCS index. Adjust the values accordingly. [0] http://www.revolutionwifi.net/revolutionwifi/2014/09/wi-fi-snr-to-mcs-data-rate-mapping.html [1] https://higher-frequency.blogspot.com/2016/10/80211n-80211ac-data-rates-and-snr.html [2] https://www.wlanpros.com/resources/mcs-index-802-11ac-vht-chart/ Signed-off-by: Matthew Wang <matthewmwang@xxxxxxxxxxxx> --- wpa_supplicant/scan.c | 74 ++++++++++++++++++++++++------------------- 1 file changed, 42 insertions(+), 32 deletions(-) diff --git a/wpa_supplicant/scan.c b/wpa_supplicant/scan.c index db1f6e1fa..98b0408d8 100644 --- a/wpa_supplicant/scan.c +++ b/wpa_supplicant/scan.c @@ -2185,67 +2185,77 @@ void scan_snr(struct wpa_scan_res *res) } -static unsigned int max_ht20_rate(int snr) +static unsigned int max_ht20_rate(int snr, int vht) { - if (snr < 6) + if (snr < 2) + return 0; + if (snr < 5) return 6500; /* HT20 MCS0 */ - if (snr < 8) + if (snr < 9) return 13000; /* HT20 MCS1 */ - if (snr < 13) + if (snr < 11) return 19500; /* HT20 MCS2 */ - if (snr < 17) + if (snr < 15) return 26000; /* HT20 MCS3 */ - if (snr < 20) + if (snr < 18) return 39000; /* HT20 MCS4 */ - if (snr < 23) + if (snr < 20) return 52000; /* HT20 MCS5 */ - if (snr < 24) + if (snr < 25) return 58500; /* HT20 MCS6 */ - return 65000; /* HT20 MCS7 */ + if (snr < 29 || !vht) + return 65000; /* HT20 MCS7 */ + return 78000; /* VHT20 MCS8 */ } -static unsigned int max_ht40_rate(int snr) +static unsigned int max_ht40_rate(int snr, int vht) { - if (snr < 3) + if (snr < 5) + return 0; + if (snr < 8) return 13500; /* HT40 MCS0 */ - if (snr < 6) + if (snr < 12) return 27000; /* HT40 MCS1 */ - if (snr < 10) + if (snr < 14) return 40500; /* HT40 MCS2 */ - if (snr < 15) + if (snr < 18) return 54000; /* HT40 MCS3 */ - if (snr < 17) + if (snr < 21) return 81000; /* HT40 MCS4 */ - if (snr < 22) + if (snr < 23) return 108000; /* HT40 MCS5 */ - if (snr < 24) + if (snr < 28) return 121500; /* HT40 MCS6 */ - return 135000; /* HT40 MCS7 */ + if (snr < 32 || !vht) + return 135000; /* HT40 MCS7 */ + if (snr < 34) + return 162000; /* VHT40 MCS8 */ + return 180000; /* VHT40 MCS9 */ } static unsigned int max_vht80_rate(int snr) { - if (snr < 1) + if (snr < 8) return 0; - if (snr < 2) + if (snr < 11) return 29300; /* VHT80 MCS0 */ - if (snr < 5) + if (snr < 15) return 58500; /* VHT80 MCS1 */ - if (snr < 9) + if (snr < 17) return 87800; /* VHT80 MCS2 */ - if (snr < 11) + if (snr < 21) return 117000; /* VHT80 MCS3 */ - if (snr < 15) + if (snr < 24) return 175500; /* VHT80 MCS4 */ - if (snr < 16) + if (snr < 26) return 234000; /* VHT80 MCS5 */ - if (snr < 18) + if (snr < 31) return 263300; /* VHT80 MCS6 */ - if (snr < 20) + if (snr < 35) return 292500; /* VHT80 MCS7 */ - if (snr < 22) + if (snr < 37) return 351000; /* VHT80 MCS8 */ return 390000; /* VHT80 MCS9 */ } @@ -2285,7 +2295,7 @@ unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s, if (capab == CAPAB_HT || capab == CAPAB_HT40 || capab == CAPAB_VHT) { ie = get_ie(ies, ies_len, WLAN_EID_HT_CAP); if (ie) { - tmp = max_ht20_rate(snr); + tmp = max_ht20_rate(snr, 0); if (tmp > est) est = tmp; } @@ -2295,7 +2305,7 @@ unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s, ie = get_ie(ies, ies_len, WLAN_EID_HT_OPERATION); if (ie && ie[1] >= 2 && (ie[3] & HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK)) { - tmp = max_ht40_rate(snr); + tmp = max_ht40_rate(snr, 0); if (tmp > est) est = tmp; } @@ -2305,7 +2315,7 @@ unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s, /* Use +1 to assume VHT is always faster than HT */ ie = get_ie(ies, ies_len, WLAN_EID_VHT_CAP); if (ie) { - tmp = max_ht20_rate(snr) + 1; + tmp = max_ht20_rate(snr, 1) + 1; if (tmp > est) est = tmp; @@ -2313,7 +2323,7 @@ unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s, if (ie && ie[1] >= 2 && (ie[3] & HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK)) { - tmp = max_ht40_rate(snr) + 1; + tmp = max_ht40_rate(snr, 1) + 1; if (tmp > est) est = tmp; } -- 2.25.1.481.gfbce0eb801-goog _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
