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 * 3. The name of David Young may not be used to endorse or promote 15 * products derived from this software without specific prior 16 * written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY 19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 20 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 21 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David 22 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 26 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 29 * OF SUCH DAMAGE. 30 */ 31 32 #ifndef _NET80211_IEEE80211_RSSADAPT_H_ 33 #define _NET80211_IEEE80211_RSSADAPT_H_ 34 35 /* Data-rate adaptation loosely based on "Link Adaptation Strategy 36 * for IEEE 802.11 WLAN via Received Signal Strength Measurement" 37 * by Javier del Prado Pavon and Sunghyun Choi. 38 */ 39 40 /* Buckets for frames 0-128 bytes long, 129-1024, 1025-maximum. */ 41 #define IEEE80211_RSSADAPT_BKTS 3 42 #define IEEE80211_RSSADAPT_BKT0 128 43 #define IEEE80211_RSSADAPT_BKTPOWER 3 /* 2**_BKTPOWER */ 44 45 #define ieee80211_rssadapt_thresh_new \ 46 (ieee80211_rssadapt_thresh_denom - ieee80211_rssadapt_thresh_old) 47 #define ieee80211_rssadapt_decay_new \ 48 (ieee80211_rssadapt_decay_denom - ieee80211_rssadapt_decay_old) 49 #define ieee80211_rssadapt_avgrssi_new \ 50 (ieee80211_rssadapt_avgrssi_denom - ieee80211_rssadapt_avgrssi_old) 51 52 struct ieee80211_rssadapt_expavgctl { 53 /* RSS threshold decay. */ 54 u_int rc_decay_denom; 55 u_int rc_decay_old; 56 /* RSS threshold update. */ 57 u_int rc_thresh_denom; 58 u_int rc_thresh_old; 59 /* RSS average update. */ 60 u_int rc_avgrssi_denom; 61 u_int rc_avgrssi_old; 62 }; 63 64 struct ieee80211_rssadapt { 65 /* exponential average RSSI << 8 */ 66 u_int16_t ra_avg_rssi; 67 /* Tx failures in this update interval */ 68 u_int32_t ra_nfail; 69 /* Tx successes in this update interval */ 70 u_int32_t ra_nok; 71 /* exponential average packets/second */ 72 u_int32_t ra_pktrate; 73 /* RSSI threshold for each Tx rate */ 74 u_int16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS] 75 [IEEE80211_RATE_SIZE]; 76 struct timeval ra_last_raise; 77 struct timeval ra_raise_interval; 78 }; 79 80 /* Properties of a Tx packet, for link adaptation. */ 81 struct ieee80211_rssdesc { 82 u_int id_len; /* Tx packet length */ 83 u_int id_rateidx; /* index into ni->ni_rates */ 84 struct ieee80211_node *id_node; /* destination STA MAC */ 85 u_int8_t id_rssi; /* destination STA avg RSS @ 86 * Tx time 87 */ 88 }; 89 90 void ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *); 91 void ieee80211_rssadapt_input(struct ieee80211com *, struct ieee80211_node *, 92 struct ieee80211_rssadapt *, int); 93 void ieee80211_rssadapt_lower_rate(struct ieee80211com *, 94 struct ieee80211_node *, struct ieee80211_rssadapt *, 95 struct ieee80211_rssdesc *); 96 void ieee80211_rssadapt_raise_rate(struct ieee80211com *, 97 struct ieee80211_rssadapt *, struct ieee80211_rssdesc *); 98 int ieee80211_rssadapt_choose(struct ieee80211_rssadapt *, 99 struct ieee80211_rateset *, struct ieee80211_frame *, u_int, int, 100 const char *, int); 101 #ifdef IEEE80211_DEBUG 102 extern int ieee80211_rssadapt_debug; 103 #endif /* IEEE80211_DEBUG */ 104 105 #endif /* !_NET80211_IEEE80211_RSSADAPT_H_ */ 106 107