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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.
*/
#ifndef _NET80211_IEEE80211_RSSADAPT_H_
#define _NET80211_IEEE80211_RSSADAPT_H_
/* 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 IEEE80211_RSSADAPT_BKTS 3
#define IEEE80211_RSSADAPT_BKT0 128
#define IEEE80211_RSSADAPT_BKTPOWER 3 /* 2**_BKTPOWER */
struct ieee80211_rssadapt {
struct ieee80211vap *vap;
int interval; /* update interval (ticks) */
};
struct ieee80211_rssadapt_node {
struct ieee80211_rssadapt *ra_rs; /* backpointer */
struct ieee80211_rateset ra_rates; /* negotiated rates */
int ra_rix; /* current rate index */
int ra_ticks; /* time of last update */
int ra_last_raise; /* time of last rate raise */
int ra_raise_interval; /* rate raise time threshold */
/* Tx failures in this update interval */
uint32_t ra_nfail;
/* Tx successes in this update interval */
uint32_t ra_nok;
/* exponential average packets/second */
uint32_t ra_pktrate;
/* RSSI threshold for each Tx rate */
uint16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS]
[IEEE80211_RATE_SIZE];
};
void ieee80211_rssadapt_init(struct ieee80211_rssadapt *,
struct ieee80211vap *, int);
void ieee80211_rssadapt_cleanup(struct ieee80211_rssadapt *);
void ieee80211_rssadapt_setinterval(struct ieee80211_rssadapt *, int);
void ieee80211_rssadapt_node_init(struct ieee80211_rssadapt *,
struct ieee80211_rssadapt_node *, struct ieee80211_node *);
int ieee80211_rssadapt_choose(struct ieee80211_node *,
struct ieee80211_rssadapt_node *, u_int);
/* NB: these are public only for the inline below */
void ieee80211_rssadapt_raise_rate(struct ieee80211_rssadapt_node *,
int pktlen, int rssi);
void ieee80211_rssadapt_lower_rate(struct ieee80211_rssadapt_node *,
int pktlen, int rssi);
#define IEEE80211_RSSADAPT_SUCCESS 1
#define IEEE80211_RSSADAPT_FAILURE 0
static __inline void
ieee80211_rssadapt_tx_complete(struct ieee80211_rssadapt_node *ra,
int success, int pktlen, int rssi)
{
if (success) {
ra->ra_nok++;
if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates &&
(ticks - ra->ra_last_raise) >= ra->ra_raise_interval)
ieee80211_rssadapt_raise_rate(ra, pktlen, rssi);
} else {
ra->ra_nfail++;
ieee80211_rssadapt_lower_rate(ra, pktlen, rssi);
}
}
#endif /* _NET80211_IEEE80211_RSSADAPT_H_ */
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