Add support to estimate throughput for VHT 160/80+80 MHz supporting APs

Add support to calculate estimated throughputs for APs which support the
160 MHz (including 80+80 MHz) mode in VHT. The minimum SNR values for
VHT 160 MHz mode are derived from minimum SNR values used for VHT 80 MHz
mode + 3 dBm. The min-SNR values are derived relatively based on the
information that the minimum sensitivity levels defined in Table 21-25
(Receiver minimum input level sensitivity) in IEEE Std 802.11-2020 for
the 160 MHz mode are higher by 3 dBm compared to the values of the 80
MHz mode for each rate.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/wpa_supplicant/scan.c b/wpa_supplicant/scan.c
index 63e59fe87671f5c4653611ce7c9c44267c35211e..d34bef3c9b40896ed59cae645cd0f958a94d5581 100644 (file)
--- a/wpa_supplicant/scan.c
+++ b/wpa_supplicant/scan.c
@@ -2276,6 +2276,22 @@ static const struct minsnr_bitrate_entry vht80_table[] = {
 };
 
 
+static const struct minsnr_bitrate_entry vht160_table[] = {
+       { 0, 0 },
+       { 11, 58500 },  /* VHT160 MCS0 */
+       { 14, 117000 }, /* VHT160 MCS1 */
+       { 18, 175500 }, /* VHT160 MCS2 */
+       { 20, 234000 }, /* VHT160 MCS3 */
+       { 24, 351000 }, /* VHT160 MCS4 */
+       { 27, 468000 }, /* VHT160 MCS5 */
+       { 29, 526500 }, /* VHT160 MCS6 */
+       { 34, 585000 }, /* VHT160 MCS7 */
+       { 38, 702000 }, /* VHT160 MCS8 */
+       { 40, 780000 }, /* VHT160 MCS9 */
+       { -1, 780000 }  /* SNR > 37 */
+};
+
+
 static unsigned int interpolate_rate(int snr, int snr0, int snr1,
                                     int rate0, int rate1)
 {
@@ -2320,6 +2336,12 @@ static unsigned int max_vht80_rate(int snr)
 }
 
 
+static unsigned int max_vht160_rate(int snr)
+{
+       return max_rate(vht160_table, snr, 1);
+}
+
+
 unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s,
                              const u8 *ies, size_t ies_len, int rate,
                              int snr, int freq)
@@ -2396,6 +2418,8 @@ 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) {
+                       bool vht80 = false, vht160 = false;
+
                        tmp = max_ht20_rate(snr, true) + 1;
                        if (tmp > est)
                                est = tmp;
@@ -2409,13 +2433,40 @@ unsigned int wpas_get_est_tpt(const struct wpa_supplicant *wpa_s,
                                        est = tmp;
                        }
 
+                       /* Determine VHT BSS bandwidth based on IEEE Std
+                        * 802.11-2020, Table 11-23 (VHT BSs bandwidth) */
                        ie = get_ie(ies, ies_len, WLAN_EID_VHT_OPERATION);
-                       if (ie && ie[1] >= 1 &&
-                           (ie[2] & VHT_OPMODE_CHANNEL_WIDTH_MASK)) {
+                       if (ie && ie[1] >= 3) {
+                               u8 cw = ie[2] & VHT_OPMODE_CHANNEL_WIDTH_MASK;
+                               u8 seg0 = ie[3];
+                               u8 seg1 = ie[4];
+
+                               if (cw)
+                                       vht80 = true;
+                               if (cw == 2 ||
+                                   (cw == 3 &&
+                                    (seg1 > 0 && abs(seg1 - seg0) == 16)))
+                                       vht160 = true;
+                               if (cw == 1 &&
+                                   ((seg1 > 0 && abs(seg1 - seg0) == 8) ||
+                                    (seg1 > 0 && abs(seg1 - seg0) == 16)))
+                                       vht160 = true;
+                       }
+
+                       if (vht80) {
                                tmp = max_vht80_rate(snr) + 1;
                                if (tmp > est)
                                        est = tmp;
                        }
+
+                       if (vht160 &&
+                           (hw_mode->vht_capab &
+                            (VHT_CAP_SUPP_CHAN_WIDTH_160MHZ |
+                             VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))) {
+                               tmp = max_vht160_rate(snr) + 1;
+                               if (tmp > est)
+                                       est = tmp;
+                       }
                }
        }