[PATCH 2/2] Adjust the RSSI and throughput estimate in roaming algorithm

[Jouni Malinen]

On Fri, Sep 22, 2023 at 05:51:13PM +0000, Kaidong Wang wrote:
> The max transmit power of Standard Power (SP) Access Points (AP) in the
> 6 GHz band is limited by effective isotropic radiated power (EIRP),
> while the max transmit power of Low Power Indoor (LPI) APs in the 6 GHz
> band is limited by power spectral density (PSD). Therefore the max
> transmit power of LPI APs grows as the channel width increases. However,
> the roaming algorithm takes signal level as a constant value regardless
> of the channel width.
> 
> Adjust the RSSI, SNR and throughput estimate based on max transmit power
> config in roaming algorithm.

> diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
> @@ -1989,11 +1989,19 @@ int wpa_supplicant_need_to_roam_within_ess(struct wpa_supplicant *wpa_s,
> -	int cur_snr = 0;
> +	int cur_snr = 0, sel_snr = 0;
>  	int ret = 0;
> +	int rssi_bump = 0, noise_bump = 0;

Hmm.. rssi_bump and noise_bump are completely unused in this function
and sel_snr is only assigned.. Is this missing something?

> +	/*
> +	 * Adjust the SNR of BSSes based on the channel width.
> +	 */
> +	cur_level += wpas_channel_width_rssi_bump(cur_ies, cur_ie_len,
> +						  current_bss->max_cw);
> +	cur_snr = wpas_adjust_snr_by_chanwidth(cur_ies, cur_ie_len,
> +					       current_bss->max_cw, cur_snr);
> +
> +	sel_est = selected->est_throughput;
> +	sel_level = selected->level +
> +		    wpas_channel_width_rssi_bump(sel_ies, sel_ie_len,
> +						 selected->max_cw);
> +	sel_snr = wpas_adjust_snr_by_chanwidth(sel_ies, sel_ie_len,
> +					       selected->max_cw, selected->snr);

That sel_snr is not used for anything and that function has no
side-effects either, so it is not clear what this is trying to achieve.

-- 
Jouni Malinen                                            PGP id EFC895FA