1 /* $FreeBSD$ */ 2 /* $NetBSD: ieee80211_rssadapt.h,v 1.4 2005/02/26 22:45:09 perry Exp $ */ 3 /*- 4 * Copyright (c) 2003, 2004 David Young. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or 7 * without modification, are permitted provided that the following 8 * conditions are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following 13 * disclaimer in the documentation and/or other materials provided 14 * with the distribution. 15 * 3. The name of David Young may not be used to endorse or promote 16 * products derived from this software without specific prior 17 * written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY 20 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 22 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David 23 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 25 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 27 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 30 * OF SUCH DAMAGE. 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 struct ieee80211_rssadapt { 46 struct ieee80211vap *vap; 47 int interval; /* update interval (ticks) */ 48 }; 49 50 struct ieee80211_rssadapt_node { 51 struct ieee80211_rssadapt *ra_rs; /* backpointer */ 52 struct ieee80211_rateset ra_rates; /* negotiated rates */ 53 int ra_rix; /* current rate index */ 54 int ra_ticks; /* time of last update */ 55 int ra_last_raise; /* time of last rate raise */ 56 int ra_raise_interval; /* rate raise time threshold */ 57 58 /* Tx failures in this update interval */ 59 uint32_t ra_nfail; 60 /* Tx successes in this update interval */ 61 uint32_t ra_nok; 62 /* exponential average packets/second */ 63 uint32_t ra_pktrate; 64 /* RSSI threshold for each Tx rate */ 65 uint16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS] 66 [IEEE80211_RATE_SIZE]; 67 }; 68 69 void ieee80211_rssadapt_init(struct ieee80211_rssadapt *, 70 struct ieee80211vap *, int); 71 void ieee80211_rssadapt_cleanup(struct ieee80211_rssadapt *); 72 void ieee80211_rssadapt_setinterval(struct ieee80211_rssadapt *, int); 73 void ieee80211_rssadapt_node_init(struct ieee80211_rssadapt *, 74 struct ieee80211_rssadapt_node *, struct ieee80211_node *); 75 int ieee80211_rssadapt_choose(struct ieee80211_node *, 76 struct ieee80211_rssadapt_node *, u_int); 77 78 /* NB: these are public only for the inline below */ 79 void ieee80211_rssadapt_raise_rate(struct ieee80211_rssadapt_node *, 80 int pktlen, int rssi); 81 void ieee80211_rssadapt_lower_rate(struct ieee80211_rssadapt_node *, 82 int pktlen, int rssi); 83 84 #define IEEE80211_RSSADAPT_SUCCESS 1 85 #define IEEE80211_RSSADAPT_FAILURE 0 86 87 static __inline void 88 ieee80211_rssadapt_tx_complete(struct ieee80211_rssadapt_node *ra, 89 int success, int pktlen, int rssi) 90 { 91 if (success) { 92 ra->ra_nok++; 93 if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates && 94 (ticks - ra->ra_last_raise) >= ra->ra_raise_interval) 95 ieee80211_rssadapt_raise_rate(ra, pktlen, rssi); 96 } else { 97 ra->ra_nfail++; 98 ieee80211_rssadapt_lower_rate(ra, pktlen, rssi); 99 } 100 } 101 #endif /* _NET80211_IEEE80211_RSSADAPT_H_ */ 102