sys/net80211/ieee80211_rssadapt.h

   1 /* $NetBSD: ieee80211_rssadapt.h,v 1.6 2005/12/10 23:26:35 elad Exp $ */
   2 /*-
   3  * Copyright (c) 2003, 2004 David Young.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or
   6  * without modification, are permitted provided that the following
   7  * conditions are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above
  11  *    copyright notice, this list of conditions and the following
  12  *    disclaimer in the documentation and/or other materials provided
  13  *    with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
  16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  17  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  18  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL David
  19  * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  21  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  26  * OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef _NET80211_IEEE80211_RSSADAPT_H_
  30 #define _NET80211_IEEE80211_RSSADAPT_H_
  31
  32 /* Data-rate adaptation loosely based on "Link Adaptation Strategy
  33  * for IEEE 802.11 WLAN via Received Signal Strength Measurement"
  34  * by Javier del Prado Pavon and Sunghyun Choi.
  35  */
  36
  37 /* Buckets for frames 0-128 bytes long, 129-1024, 1025-maximum. */
  38 #define IEEE80211_RSSADAPT_BKTS         3
  39 #define IEEE80211_RSSADAPT_BKT0         128
  40 #define IEEE80211_RSSADAPT_BKTPOWER     3       /* 2**_BKTPOWER */
  41
  42 #define ieee80211_rssadapt_thresh_new \
  43     (ieee80211_rssadapt_thresh_denom - ieee80211_rssadapt_thresh_old)
  44 #define ieee80211_rssadapt_decay_new \
  45     (ieee80211_rssadapt_decay_denom - ieee80211_rssadapt_decay_old)
  46 #define ieee80211_rssadapt_avgrssi_new \
  47     (ieee80211_rssadapt_avgrssi_denom - ieee80211_rssadapt_avgrssi_old)
  48
  49 struct ieee80211_rssadapt_expavgctl {
  50         /* RSS threshold decay. */
  51         u_int rc_decay_denom;
  52         u_int rc_decay_old;
  53         /* RSS threshold update. */
  54         u_int rc_thresh_denom;
  55         u_int rc_thresh_old;
  56         /* RSS average update. */
  57         u_int rc_avgrssi_denom;
  58         u_int rc_avgrssi_old;
  59 };
  60
  61 struct ieee80211_rssadapt {
  62         /* exponential average RSSI << 8 */
  63         u_int16_t               ra_avg_rssi;
  64         /* Tx failures in this update interval */
  65         u_int32_t               ra_nfail;
  66         /* Tx successes in this update interval */
  67         u_int32_t               ra_nok;
  68         /* exponential average packets/second */
  69         u_int32_t               ra_pktrate;
  70         /* RSSI threshold for each Tx rate */
  71         u_int16_t               ra_rate_thresh[IEEE80211_RSSADAPT_BKTS]
  72                                               [IEEE80211_RATE_SIZE];
  73         struct timeval          ra_last_raise;
  74         struct timeval          ra_raise_interval;
  75 };
  76
  77 /* Properties of a Tx packet, for link adaptation. */
  78 struct ieee80211_rssdesc {
  79         u_int                    id_len;        /* Tx packet length */
  80         u_int                    id_rateidx;    /* index into ni->ni_rates */
  81         struct ieee80211_node   *id_node;       /* destination STA MAC */
  82         u_int8_t                 id_rssi;       /* destination STA avg RSS @
  83                                                  * Tx time
  84                                                  */
  85 };
  86
  87 void    ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *);
  88 void    ieee80211_rssadapt_input(struct ieee80211com *, struct ieee80211_node *,
  89             struct ieee80211_rssadapt *, int);
  90 void    ieee80211_rssadapt_lower_rate(struct ieee80211com *,
  91             struct ieee80211_node *, struct ieee80211_rssadapt *,
  92             struct ieee80211_rssdesc *);
  93 void    ieee80211_rssadapt_raise_rate(struct ieee80211com *,
  94             struct ieee80211_rssadapt *, struct ieee80211_rssdesc *);
  95 int     ieee80211_rssadapt_choose(struct ieee80211_rssadapt *,
  96             struct ieee80211_rateset *, struct ieee80211_frame *, u_int, int,
  97             const char *, int);
  98 #ifdef IEEE80211_DEBUG
  99 extern int ieee80211_rssadapt_debug;
 100 #endif /* IEEE80211_DEBUG */
 101
 102 #endif /* !_NET80211_IEEE80211_RSSADAPT_H_ */
 103