1 /* $NetBSD: ieee80211_rssadapt.h,v 1.1 2003/10/26 07:56:41 dyoung 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 /* 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 { 50 /* exponential average RSSI << 8 */ 51 u_int16_t ra_avg_rssi; 52 /* Tx failures in this update interval */ 53 u_int32_t ra_nfail; 54 /* Tx successes in this update interval */ 55 u_int32_t ra_nok; 56 /* exponential average packets/second */ 57 u_int32_t ra_pktrate; 58 /* RSSI threshold for each Tx rate */ 59 u_int16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS] 60 [IEEE80211_RATE_SIZE]; 61 struct timeval ra_last_raise; 62 struct timeval ra_raise_interval; 63 }; 64 65 /* Properties of a Tx packet, for link adaptation. */ 66 struct ieee80211_rssdesc { 67 u_int id_len; /* Tx packet length */ 68 u_int id_rateidx; /* index into ni->ni_rates */ 69 struct ieee80211_node *id_node; /* destination STA MAC */ 70 u_int8_t id_rssi; /* destination STA avg RSS @ 71 * Tx time 72 */ 73 }; 74 75 void ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *); 76 void ieee80211_rssadapt_input(struct ieee80211com *, struct ieee80211_node *, 77 struct ieee80211_rssadapt *, int); 78 void ieee80211_rssadapt_lower_rate(struct ieee80211com *, 79 struct ieee80211_node *, struct ieee80211_rssadapt *, 80 struct ieee80211_rssdesc *); 81 void ieee80211_rssadapt_raise_rate(struct ieee80211com *, 82 struct ieee80211_rssadapt *, struct ieee80211_rssdesc *); 83 84