| developer | 1a17367 | 2023-12-21 14:49:33 +0800 | [diff] [blame^] | 1 | From a615aa302064919791f3912a5cf1a908390414df Mon Sep 17 00:00:00 2001 |
| 2 | From: Nicolas Escande <nico.escande@gmail.com> |
| 3 | Date: Wed, 27 Apr 2022 15:37:02 +0200 |
| 4 | Subject: [PATCH 04/50] ACS: Allow selecting a better channel when using |
| 5 | 40/80/160 MHz |
| 6 | |
| 7 | When considering a channel for a bandwidth of 40/80/160 MHZ on the 5 GHz |
| 8 | or 6 GHz band, allow selecting one of the other channels in the segment |
| 9 | instead of the first one. This is done only if the other channel's |
| 10 | interference_factor is lower than the first one's. |
| 11 | |
| 12 | Signed-off-by: Nicolas Escande <nico.escande@gmail.com> |
| 13 | --- |
| 14 | src/ap/acs.c | 25 +++++++++++++++++++++++-- |
| 15 | 1 file changed, 23 insertions(+), 2 deletions(-) |
| 16 | |
| 17 | diff --git a/src/ap/acs.c b/src/ap/acs.c |
| 18 | index 78d1feb..130e135 100644 |
| 19 | --- a/src/ap/acs.c |
| 20 | +++ b/src/ap/acs.c |
| 21 | @@ -712,7 +712,7 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface, |
| 22 | struct hostapd_channel_data **ideal_chan, |
| 23 | long double *ideal_factor) |
| 24 | { |
| 25 | - struct hostapd_channel_data *chan, *adj_chan = NULL; |
| 26 | + struct hostapd_channel_data *chan, *adj_chan = NULL, *best; |
| 27 | long double factor; |
| 28 | int i, j; |
| 29 | unsigned int k; |
| 30 | @@ -720,8 +720,9 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface, |
| 31 | for (i = 0; i < mode->num_channels; i++) { |
| 32 | double total_weight; |
| 33 | struct acs_bias *bias, tmp_bias; |
| 34 | + bool update_best = true; |
| 35 | |
| 36 | - chan = &mode->channels[i]; |
| 37 | + best = chan = &mode->channels[i]; |
| 38 | |
| 39 | /* Since in the current ACS implementation the first channel is |
| 40 | * always a primary channel, skip channels not available as |
| 41 | @@ -807,7 +808,15 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface, |
| 42 | if (acs_usable_chan(adj_chan)) { |
| 43 | factor += adj_chan->interference_factor; |
| 44 | total_weight += 1; |
| 45 | + } else { |
| 46 | + update_best = false; |
| 47 | } |
| 48 | + |
| 49 | + /* find the best channel in this segment */ |
| 50 | + if (update_best && |
| 51 | + adj_chan->interference_factor < |
| 52 | + best->interference_factor) |
| 53 | + best = adj_chan; |
| 54 | } |
| 55 | |
| 56 | if (j != n_chans) { |
| 57 | @@ -816,6 +825,18 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface, |
| 58 | continue; |
| 59 | } |
| 60 | |
| 61 | + /* If the AP is in the 5 GHz or 6 GHz band, lets prefer a less |
| 62 | + * crowded primary channel if one was found in the segment */ |
| 63 | + if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A && |
| 64 | + chan != best) { |
| 65 | + wpa_printf(MSG_DEBUG, |
| 66 | + "ACS: promoting channel %d over %d (less interference %Lg/%Lg)", |
| 67 | + best->chan, chan->chan, |
| 68 | + chan->interference_factor, |
| 69 | + best->interference_factor); |
| 70 | + chan = best; |
| 71 | + } |
| 72 | + |
| 73 | /* 2.4 GHz has overlapping 20 MHz channels. Include adjacent |
| 74 | * channel interference factor. */ |
| 75 | if (is_24ghz_mode(mode->mode)) { |
| 76 | -- |
| 77 | 2.18.0 |
| 78 | |