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/* $FreeBSD$ */
/* $NetBSD: ieee80211_rssadapt.h,v 1.4 2005/02/26 22:45:09 perry Exp $ */
/*-
* Copyright (c) 2003, 2004 David Young. All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* 3. The name of David Young may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
* Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*/
/* Data-rate adaptation loosely based on "Link Adaptation Strategy
* for IEEE 802.11 WLAN via Received Signal Strength Measurement"
* by Javier del Prado Pavon and Sunghyun Choi.
*/
/* Buckets for frames 0-128 bytes long, 129-1024, 1025-maximum. */
#define RAL_RSSADAPT_BKTS 3
#define RAL_RSSADAPT_BKT0 128
#define RAL_RSSADAPT_BKTPOWER 3 /* 2**_BKTPOWER */
#define ral_rssadapt_thresh_new \
(ral_rssadapt_thresh_denom - ral_rssadapt_thresh_old)
#define ral_rssadapt_decay_new \
(ral_rssadapt_decay_denom - ral_rssadapt_decay_old)
#define ral_rssadapt_avgrssi_new \
(ral_rssadapt_avgrssi_denom - ral_rssadapt_avgrssi_old)
struct ral_rssadapt_expavgctl {
/* RSS threshold decay. */
u_int rc_decay_denom;
u_int rc_decay_old;
/* RSS threshold update. */
u_int rc_thresh_denom;
u_int rc_thresh_old;
/* RSS average update. */
u_int rc_avgrssi_denom;
u_int rc_avgrssi_old;
};
struct ral_rssadapt {
/* exponential average RSSI << 8 */
u_int16_t ra_avg_rssi;
/* Tx failures in this update interval */
u_int32_t ra_nfail;
/* Tx successes in this update interval */
u_int32_t ra_nok;
/* exponential average packets/second */
u_int32_t ra_pktrate;
/* RSSI threshold for each Tx rate */
u_int16_t ra_rate_thresh[RAL_RSSADAPT_BKTS]
[IEEE80211_RATE_SIZE];
struct timeval ra_last_raise;
struct timeval ra_raise_interval;
};
/* Properties of a Tx packet, for link adaptation. */
struct ral_rssdesc {
u_int id_len; /* Tx packet length */
u_int id_rateidx; /* index into ni->ni_rates */
struct ieee80211_node *id_node; /* destination STA MAC */
u_int8_t id_rssi; /* destination STA avg RSS @
* Tx time
*/
};
void ral_rssadapt_updatestats(struct ral_rssadapt *);
void ral_rssadapt_input(struct ieee80211com *, struct ieee80211_node *,
struct ral_rssadapt *, int);
void ral_rssadapt_lower_rate(struct ieee80211com *,
struct ieee80211_node *, struct ral_rssadapt *,
struct ral_rssdesc *);
void ral_rssadapt_raise_rate(struct ieee80211com *,
struct ral_rssadapt *, struct ral_rssdesc *);
int ral_rssadapt_choose(struct ral_rssadapt *,
struct ieee80211_rateset *, struct ieee80211_frame *, u_int,
const char *, int);
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