ieee80211_rssadapt.c revision 1.2
1 /* $NetBSD: ieee80211_rssadapt.c,v 1.2 2003/12/07 05:29:39 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 #include <sys/param.h> 33 #include <sys/types.h> 34 #include <sys/kernel.h> /* for hz */ 35 36 #include <net/if.h> 37 #include <net/if_media.h> 38 #include <net/if_ether.h> 39 40 #include <net80211/ieee80211_var.h> 41 #include <net80211/ieee80211.h> 42 #include <net80211/ieee80211_compat.h> 43 #include <net80211/ieee80211_rssadapt.h> 44 45 #ifdef IEEE80211_DEBUG 46 static struct timeval lastrateadapt; /* time of last rate adaptation msg */ 47 static int currssadaptps = 0; /* rate-adaptation msgs this second */ 48 static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */ 49 50 #define RSSADAPT_DO_PRINT() \ 51 ((ieee80211_debug > 0) && \ 52 ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate)) 53 #define RSSADAPT_PRINTF(X) \ 54 if (RSSADAPT_DO_PRINT()) \ 55 printf X 56 57 #else 58 #define RSSADAPT_DO_PRINT() (0) 59 #define RSSADAPT_PRINTF(X) 60 #endif 61 62 /* RSS threshold decay. */ 63 u_int ieee80211_rssadapt_decay_denom = 16; 64 u_int ieee80211_rssadapt_decay_old = 15; 65 /* RSS threshold update. */ 66 u_int ieee80211_rssadapt_thresh_denom = 8; 67 u_int ieee80211_rssadapt_thresh_old = 4; 68 /* RSS average update. */ 69 u_int ieee80211_rssadapt_avgrssi_denom = 8; 70 u_int ieee80211_rssadapt_avgrssi_old = 4; 71 72 void 73 ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra) 74 { 75 long interval; 76 77 ra->ra_pktrate = 78 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2; 79 ra->ra_nfail = ra->ra_nok = 0; 80 81 /* a node is eligible for its rate to be raised every 1/10 to 10 82 * seconds, more eligible in proportion to recent packet rates. 83 */ 84 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate)); 85 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000); 86 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000); 87 } 88 89 void 90 ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni, 91 struct ieee80211_rssadapt *ra, int rssi) 92 { 93 #ifdef IEEE80211_DEBUG 94 int last_avg_rssi = ra->ra_avg_rssi; 95 #endif 96 97 ra->ra_avg_rssi = 98 (ieee80211_rssadapt_avgrssi_old * ra->ra_avg_rssi + 99 ieee80211_rssadapt_avgrssi_new * (rssi << 8)) / 100 ieee80211_rssadapt_avgrssi_denom; 101 102 RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n", 103 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr), 104 rssi, last_avg_rssi, ra->ra_avg_rssi)); 105 } 106 107 /* 108 * Adapt the data rate to suit the conditions. When a transmitted 109 * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions, 110 * raise the RSS threshold for transmitting packets of similar length at 111 * the same data rate. 112 */ 113 void 114 ieee80211_rssadapt_lower_rate(struct ieee80211com *ic, 115 struct ieee80211_node *ni, struct ieee80211_rssadapt *ra, 116 struct ieee80211_rssdesc *id) 117 { 118 struct ieee80211_rateset *rs = &ni->ni_rates; 119 u_int16_t last_thr; 120 u_int i, thridx, top; 121 122 ra->ra_nok++; 123 124 if (id->id_rateidx >= rs->rs_nrates) { 125 RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: " 126 "%s rate #%d > #%d out of bounds\n", 127 ether_sprintf(ni->ni_macaddr), id->id_rateidx, 128 rs->rs_nrates - 1)); 129 return; 130 } 131 132 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 133 i < IEEE80211_RSSADAPT_BKTS; 134 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 135 thridx = i; 136 if (id->id_len <= top) 137 break; 138 } 139 140 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx]; 141 ra->ra_rate_thresh[thridx][id->id_rateidx] = 142 (ieee80211_rssadapt_thresh_old * last_thr + 143 ieee80211_rssadapt_thresh_new * (id->id_rssi << 8)) / 144 ieee80211_rssadapt_thresh_denom; 145 146 RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n", 147 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr), 148 id->id_rssi, id->id_len, 149 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2, 150 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10, 151 last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx])); 152 } 153 154 void 155 ieee80211_rssadapt_raise_rate(struct ieee80211com *ic, 156 struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id) 157 { 158 u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr; 159 struct ieee80211_node *ni = id->id_node; 160 struct ieee80211_rateset *rs = &ni->ni_rates; 161 int i, rate, top; 162 #ifdef IEEE80211_DEBUG 163 int j; 164 #endif 165 166 ra->ra_nfail++; 167 168 if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval)) 169 return; 170 171 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 172 i < IEEE80211_RSSADAPT_BKTS; 173 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 174 thrs = &ra->ra_rate_thresh[i]; 175 if (id->id_len <= top) 176 break; 177 } 178 179 if (id->id_rateidx + 1 < rs->rs_nrates && 180 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) { 181 rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL); 182 183 RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ", 184 ic->ic_if.if_xname, 185 IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i), 186 rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1])); 187 oldthr = (*thrs)[id->id_rateidx + 1]; 188 if ((*thrs)[id->id_rateidx] == 0) 189 newthr = ra->ra_avg_rssi; 190 else 191 newthr = (*thrs)[id->id_rateidx]; 192 (*thrs)[id->id_rateidx + 1] = 193 (ieee80211_rssadapt_decay_old * oldthr + 194 ieee80211_rssadapt_decay_new * newthr) / 195 ieee80211_rssadapt_decay_denom; 196 197 RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1])); 198 } 199 200 #ifdef IEEE80211_DEBUG 201 if (RSSADAPT_DO_PRINT()) { 202 printf("%s: dst %s thresholds\n", ic->ic_if.if_xname, 203 ether_sprintf(ni->ni_macaddr)); 204 for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) { 205 printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i)); 206 for (j = 0; j < rs->rs_nrates; j++) { 207 rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL); 208 printf(", T[%d.%d] = %d", rate / 2, 209 rate * 5 % 10, ra->ra_rate_thresh[i][j]); 210 } 211 printf("\n"); 212 } 213 } 214 #endif /* IEEE80211_DEBUG */ 215 } 216
Indexes created Tue Sep 23 07:09:52 GMT 2025