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authorJouni Malinen <j@w1.fi>2016-11-13 15:46:00 (GMT)
committerJouni Malinen <j@w1.fi>2016-11-13 15:52:32 (GMT)
commit8d1e693186336f85bf5d86bd094b5c9bd6f8fd02 (patch)
tree68f595c409cfb06450ec33fb8eb607fefbf82470 /wpa_supplicant
parentfde3a531321e7fdd51a3b4893c38ed78a0c2f69f (diff)
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Use estimated throughput to avoid signal based roaming decision
Previously, the estimated throughput was used to enable roaming to a better AP. However, this information was not used when considering a roam to an AP that has better signal strength, but smaller estimated throughput. This could result in allowing roaming from 5 GHz band to 2.4 GHz band in cases where 2.4 GHz band has significantly higher signal strength, but still a lower throughput estimate. Make this less likely to happen by increasing/reducing the minimum required signal strength difference based on the estimated throughputs of the current and selected AP. In addition, add more details about the selection process to the debug log to make it easier to determine whaty happened and why. Signed-off-by: Jouni Malinen <j@w1.fi>
Diffstat (limited to 'wpa_supplicant')
-rw-r--r--wpa_supplicant/events.c52
1 files changed, 42 insertions, 10 deletions
diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
index 17f057a..210b45c 100644
--- a/wpa_supplicant/events.c
+++ b/wpa_supplicant/events.c
@@ -1396,8 +1396,9 @@ static int wpa_supplicant_need_to_roam(struct wpa_supplicant *wpa_s,
{
struct wpa_bss *current_bss = NULL;
#ifndef CONFIG_NO_ROAMING
- int min_diff;
+ int min_diff, diff;
int to_5ghz;
+ int cur_est, sel_est;
#endif /* CONFIG_NO_ROAMING */
if (wpa_s->reassociate)
@@ -1431,12 +1432,13 @@ static int wpa_supplicant_need_to_roam(struct wpa_supplicant *wpa_s,
#ifndef CONFIG_NO_ROAMING
wpa_dbg(wpa_s, MSG_DEBUG, "Considering within-ESS reassociation");
wpa_dbg(wpa_s, MSG_DEBUG, "Current BSS: " MACSTR
- " level=%d snr=%d est_throughput=%u",
- MAC2STR(current_bss->bssid), current_bss->level,
+ " freq=%d level=%d snr=%d est_throughput=%u",
+ MAC2STR(current_bss->bssid),
+ current_bss->freq, current_bss->level,
current_bss->snr, current_bss->est_throughput);
wpa_dbg(wpa_s, MSG_DEBUG, "Selected BSS: " MACSTR
- " level=%d snr=%d est_throughput=%u",
- MAC2STR(selected->bssid), selected->level,
+ " freq=%d level=%d snr=%d est_throughput=%u",
+ MAC2STR(selected->bssid), selected->freq, selected->level,
selected->snr, selected->est_throughput);
if (wpa_s->current_ssid->bssid_set &&
@@ -1462,6 +1464,14 @@ static int wpa_supplicant_need_to_roam(struct wpa_supplicant *wpa_s,
return 0;
}
+ if (current_bss->est_throughput > selected->est_throughput + 5000) {
+ wpa_dbg(wpa_s, MSG_DEBUG,
+ "Skip roam - Current BSS has better estimated throughput");
+ return 1;
+ }
+
+ cur_est = current_bss->est_throughput;
+ sel_est = selected->est_throughput;
min_diff = 2;
if (current_bss->level < 0) {
if (current_bss->level < -85)
@@ -1474,20 +1484,42 @@ static int wpa_supplicant_need_to_roam(struct wpa_supplicant *wpa_s,
min_diff = 4;
else
min_diff = 5;
+ if (cur_est > sel_est * 1.5)
+ min_diff += 10;
+ else if (cur_est > sel_est * 1.2)
+ min_diff += 5;
+ else if (cur_est > sel_est * 1.1)
+ min_diff += 2;
+ else if (cur_est > sel_est)
+ min_diff++;
}
if (to_5ghz) {
+ int reduce = 2;
+
/* Make it easier to move to 5 GHz band */
- if (min_diff > 2)
- min_diff -= 2;
+ if (sel_est > cur_est * 1.5)
+ reduce = 5;
+ else if (sel_est > cur_est * 1.2)
+ reduce = 4;
+ else if (sel_est > cur_est * 1.1)
+ reduce = 3;
+
+ if (min_diff > reduce)
+ min_diff -= reduce;
else
min_diff = 0;
}
- if (abs(current_bss->level - selected->level) < min_diff) {
- wpa_dbg(wpa_s, MSG_DEBUG, "Skip roam - too small difference "
- "in signal level");
+ diff = abs(current_bss->level - selected->level);
+ if (diff < min_diff) {
+ wpa_dbg(wpa_s, MSG_DEBUG,
+ "Skip roam - too small difference in signal level (%d < %d)",
+ diff, min_diff);
return 0;
}
+ wpa_dbg(wpa_s, MSG_DEBUG,
+ "Allow reassociation due to difference in signal level (%d >= %d)",
+ diff, min_diff);
return 1;
#else /* CONFIG_NO_ROAMING */
return 0;