1 /* $NetBSD: ieee80211_rssadapt.h,v 1.7 2009/10/19 23:19:39 rmind 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_ */ 103 104