1 /* $OpenBSD: ieee80211_rssadapt.h,v 1.4 2007/06/16 13:17:05 damien Exp $ */
2 /* $NetBSD: ieee80211_rssadapt.h,v 1.3 2004/05/06 03:03:20 dyoung Exp $ */
3
4 /*-
5 * Copyright (c) 2003, 2004 David Young. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or
8 * without modification, are permitted provided that the following
9 * conditions are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials provided
15 * with the distribution.
16 * 3. The name of David Young may not be used to endorse or promote
17 * products derived from this software without specific prior
18 * written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
21 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
22 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
23 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
24 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
26 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
28 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31 * OF SUCH DAMAGE.
32 */
33 #ifndef _NET80211_IEEE80211_RSSADAPT_H_
34 #define _NET80211_IEEE80211_RSSADAPT_H_
35
36 /* Data-rate adaptation loosely based on "Link Adaptation Strategy
37 * for IEEE 802.11 WLAN via Received Signal Strength Measurement"
38 * by Javier del Prado Pavon and Sunghyun Choi.
39 */
40
41 /* Buckets for frames 0-128 bytes long, 129-1024, 1025-maximum. */
42 #define IEEE80211_RSSADAPT_BKTS 3
43 #define IEEE80211_RSSADAPT_BKT0 128
44 #define IEEE80211_RSSADAPT_BKTPOWER 3 /* 2**_BKTPOWER */
45
46 #define ieee80211_rssadapt_thresh_new \
47 (ieee80211_rssadapt_thresh_denom - ieee80211_rssadapt_thresh_old)
48 #define ieee80211_rssadapt_decay_new \
49 (ieee80211_rssadapt_decay_denom - ieee80211_rssadapt_decay_old)
50 #define ieee80211_rssadapt_avgrssi_new \
51 (ieee80211_rssadapt_avgrssi_denom - ieee80211_rssadapt_avgrssi_old)
52
53 struct ieee80211_rssadapt_expavgctl {
54 /* RSS threshold decay. */
55 u_int rc_decay_denom;
56 u_int rc_decay_old;
57 /* RSS threshold update. */
58 u_int rc_thresh_denom;
59 u_int rc_thresh_old;
60 /* RSS average update. */
61 u_int rc_avgrssi_denom;
62 u_int rc_avgrssi_old;
63 };
64
65 struct ieee80211_rssadapt {
66 /* exponential average RSSI << 8 */
67 u_int16_t ra_avg_rssi;
68 /* Tx failures in this update interval */
69 u_int32_t ra_nfail;
70 /* Tx successes in this update interval */
71 u_int32_t ra_nok;
72 /* exponential average packets/second */
73 u_int32_t ra_pktrate;
74 /* RSSI threshold for each Tx rate */
75 u_int16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS]
76 [IEEE80211_RATE_SIZE];
77 struct timeval ra_last_raise;
78 struct timeval ra_raise_interval;
79 };
80
81 /* Properties of a Tx packet, for link adaptation. */
82 struct ieee80211_rssdesc {
83 u_int id_len; /* Tx packet length */
84 u_int id_rateidx; /* index into ni->ni_rates */
85 struct ieee80211_node *id_node; /* destination STA MAC */
86 u_int8_t id_rssi; /* destination STA avg RSS @
87 * Tx time
88 */
89 };
90
91 void ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *);
92 void ieee80211_rssadapt_input(struct ieee80211com *,
93 const struct ieee80211_node *, struct ieee80211_rssadapt *, int);
94 void ieee80211_rssadapt_lower_rate(struct ieee80211com *,
95 const struct ieee80211_node *, struct ieee80211_rssadapt *,
96 const struct ieee80211_rssdesc *);
97 void ieee80211_rssadapt_raise_rate(struct ieee80211com *,
98 struct ieee80211_rssadapt *, const struct ieee80211_rssdesc *);
99 int ieee80211_rssadapt_choose(struct ieee80211_rssadapt *,
100 const struct ieee80211_rateset *, const struct ieee80211_frame *,
101 u_int, int, const char *, int);
102 #ifdef IEEE80211_DEBUG
103 extern int ieee80211_rssadapt_debug;
104 #endif /* IEEE80211_DEBUG */
105
106 #endif /* _NET80211_IEEE80211_RSSADAPT_H_ */