ieee80211_rssadapt.c revision 1.4
1 /* $NetBSD: ieee80211_rssadapt.c,v 1.4 2004/03/29 04:09:45 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 interpolate 46 #undef interpolate 47 #endif 48 #define interpolate(parm, old, new) ((parm##_old * (old) + \ 49 (parm##_denom - parm##_old) * (new)) / \ 50 parm##_denom) 51 52 #ifdef IEEE80211_DEBUG 53 static struct timeval lastrateadapt; /* time of last rate adaptation msg */ 54 static int currssadaptps = 0; /* rate-adaptation msgs this second */ 55 static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */ 56 57 #define RSSADAPT_DO_PRINT() \ 58 ((ieee80211_debug > 0) && \ 59 ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate)) 60 #define RSSADAPT_PRINTF(X) \ 61 if (RSSADAPT_DO_PRINT()) \ 62 printf X 63 64 #else 65 #define RSSADAPT_DO_PRINT() (0) 66 #define RSSADAPT_PRINTF(X) 67 #endif 68 69 struct ieee80211_rssadapt_expavgctl master_expavgctl = { 70 rc_decay_denom : 16, 71 rc_decay_old : 15, 72 rc_thresh_denom : 8, 73 rc_thresh_old : 4, 74 rc_avgrssi_denom : 8, 75 rc_avgrssi_old : 4 76 }; 77 78 int 79 ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra, 80 struct ieee80211_rateset *rs, struct ieee80211_frame *wh, u_int len, 81 int fixed_rate, const char *dvname, int do_not_adapt) 82 { 83 u_int16_t (*thrs)[IEEE80211_RATE_SIZE]; 84 int flags = 0, i, rateidx = 0, thridx, top; 85 86 if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL) 87 flags |= IEEE80211_RATE_BASIC; 88 89 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 90 i < IEEE80211_RSSADAPT_BKTS; 91 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 92 thridx = i; 93 if (len <= top) 94 break; 95 } 96 97 thrs = &ra->ra_rate_thresh[thridx]; 98 99 if (fixed_rate != -1) { 100 if ((rs->rs_rates[fixed_rate] & flags) == flags) { 101 rateidx = fixed_rate; 102 goto out; 103 } 104 flags |= IEEE80211_RATE_BASIC; 105 i = fixed_rate; 106 } else 107 i = rs->rs_nrates; 108 109 while (--i >= 0) { 110 rateidx = i; 111 if ((rs->rs_rates[i] & flags) != flags) 112 continue; 113 if (do_not_adapt) 114 break; 115 if ((*thrs)[i] < ra->ra_avg_rssi) 116 break; 117 } 118 119 out: 120 if (dvname != NULL) { 121 printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n", 122 dvname, ether_sprintf(wh->i_addr1), len, 123 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2, 124 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10, 125 (*thrs)[rateidx], ra->ra_avg_rssi); 126 } 127 return rateidx; 128 } 129 130 void 131 ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra) 132 { 133 long interval; 134 135 ra->ra_pktrate = 136 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2; 137 ra->ra_nfail = ra->ra_nok = 0; 138 139 /* a node is eligible for its rate to be raised every 1/10 to 10 140 * seconds, more eligible in proportion to recent packet rates. 141 */ 142 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate)); 143 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000); 144 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000); 145 } 146 147 void 148 ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni, 149 struct ieee80211_rssadapt *ra, int rssi) 150 { 151 #ifdef IEEE80211_DEBUG 152 int last_avg_rssi = ra->ra_avg_rssi; 153 #endif 154 155 ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi, 156 ra->ra_avg_rssi, (rssi << 8)); 157 158 RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n", 159 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr), 160 rssi, last_avg_rssi, ra->ra_avg_rssi)); 161 } 162 163 /* 164 * Adapt the data rate to suit the conditions. When a transmitted 165 * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions, 166 * raise the RSS threshold for transmitting packets of similar length at 167 * the same data rate. 168 */ 169 void 170 ieee80211_rssadapt_lower_rate(struct ieee80211com *ic, 171 struct ieee80211_node *ni, struct ieee80211_rssadapt *ra, 172 struct ieee80211_rssdesc *id) 173 { 174 struct ieee80211_rateset *rs = &ni->ni_rates; 175 u_int16_t last_thr; 176 u_int i, thridx, top; 177 178 ra->ra_nfail++; 179 180 if (id->id_rateidx >= rs->rs_nrates) { 181 RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: " 182 "%s rate #%d > #%d out of bounds\n", 183 ether_sprintf(ni->ni_macaddr), id->id_rateidx, 184 rs->rs_nrates - 1)); 185 return; 186 } 187 188 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 189 i < IEEE80211_RSSADAPT_BKTS; 190 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 191 thridx = i; 192 if (id->id_len <= top) 193 break; 194 } 195 196 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx]; 197 ra->ra_rate_thresh[thridx][id->id_rateidx] = 198 interpolate(master_expavgctl.rc_thresh, last_thr, 199 (id->id_rssi << 8)); 200 201 RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n", 202 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr), 203 id->id_rssi, id->id_len, 204 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2, 205 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10, 206 last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx])); 207 } 208 209 void 210 ieee80211_rssadapt_raise_rate(struct ieee80211com *ic, 211 struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id) 212 { 213 u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr; 214 struct ieee80211_node *ni = id->id_node; 215 struct ieee80211_rateset *rs = &ni->ni_rates; 216 int i, rate, top; 217 #ifdef IEEE80211_DEBUG 218 int j; 219 #endif 220 221 ra->ra_nok++; 222 223 if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval)) 224 return; 225 226 for (i = 0, top = IEEE80211_RSSADAPT_BKT0; 227 i < IEEE80211_RSSADAPT_BKTS; 228 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) { 229 thrs = &ra->ra_rate_thresh[i]; 230 if (id->id_len <= top) 231 break; 232 } 233 234 if (id->id_rateidx + 1 < rs->rs_nrates && 235 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) { 236 rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL); 237 238 RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ", 239 ic->ic_if.if_xname, 240 IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i), 241 rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1])); 242 oldthr = (*thrs)[id->id_rateidx + 1]; 243 if ((*thrs)[id->id_rateidx] == 0) 244 newthr = ra->ra_avg_rssi; 245 else 246 newthr = (*thrs)[id->id_rateidx]; 247 (*thrs)[id->id_rateidx + 1] = 248 interpolate(master_expavgctl.rc_decay, oldthr, newthr); 249 250 RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1])); 251 } 252 253 #ifdef IEEE80211_DEBUG 254 if (RSSADAPT_DO_PRINT()) { 255 printf("%s: dst %s thresholds\n", ic->ic_if.if_xname, 256 ether_sprintf(ni->ni_macaddr)); 257 for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) { 258 printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i)); 259 for (j = 0; j < rs->rs_nrates; j++) { 260 rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL); 261 printf(", T[%d.%d] = %d", rate / 2, 262 rate * 5 % 10, ra->ra_rate_thresh[i][j]); 263 } 264 printf("\n"); 265 } 266 } 267 #endif /* IEEE80211_DEBUG */ 268 } 269
Indexes created Mon Sep 22 13:09:51 GMT 2025