1/* $OpenBSD: ieee80211_rssadapt.h,v 1.5 2010/07/17 16:25:09 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 *
17 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
19 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
20 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
21 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
23 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
28 * OF SUCH DAMAGE.
29 */
30#ifndef _NET80211_IEEE80211_RSSADAPT_H_
31#define _NET80211_IEEE80211_RSSADAPT_H_
32
33/* Data-rate adaptation loosely based on "Link Adaptation Strategy
34 * for IEEE 802.11 WLAN via Received Signal Strength Measurement"
35 * by Javier del Prado Pavon and Sunghyun Choi.
36 */
37
38/* Buckets for frames 0-128 bytes long, 129-1024, 1025-maximum. */
39#define IEEE80211_RSSADAPT_BKTS 3
40#define IEEE80211_RSSADAPT_BKT0 128
41#define IEEE80211_RSSADAPT_BKTPOWER 3 /* 2**_BKTPOWER */
42
43#define ieee80211_rssadapt_thresh_new \
44 (ieee80211_rssadapt_thresh_denom - ieee80211_rssadapt_thresh_old)
45#define ieee80211_rssadapt_decay_new \
46 (ieee80211_rssadapt_decay_denom - ieee80211_rssadapt_decay_old)
47#define ieee80211_rssadapt_avgrssi_new \
48 (ieee80211_rssadapt_avgrssi_denom - ieee80211_rssadapt_avgrssi_old)
49
50struct ieee80211_rssadapt_expavgctl {
51 /* RSS threshold decay. */
52 u_int rc_decay_denom;
53 u_int rc_decay_old;
54 /* RSS threshold update. */
55 u_int rc_thresh_denom;
56 u_int rc_thresh_old;
57 /* RSS average update. */
58 u_int rc_avgrssi_denom;
59 u_int rc_avgrssi_old;
60};
61
62struct ieee80211_rssadapt {
63 /* exponential average RSSI << 8 */
64 u_int16_t ra_avg_rssi;
65 /* Tx failures in this update interval */
66 u_int32_t ra_nfail;
67 /* Tx successes in this update interval */
68 u_int32_t ra_nok;
69 /* exponential average packets/second */
70 u_int32_t ra_pktrate;
71 /* RSSI threshold for each Tx rate */
72 u_int16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS]
73 [IEEE80211_RATE_SIZE];
74 struct timeval ra_last_raise;
75 struct timeval ra_raise_interval;
76};
77
78/* Properties of a Tx packet, for link adaptation. */
79struct ieee80211_rssdesc {
80 u_int id_len; /* Tx packet length */
81 u_int id_rateidx; /* index into ni->ni_rates */
82 struct ieee80211_node *id_node; /* destination STA MAC */
83 u_int8_t id_rssi; /* destination STA avg RSS @
84 * Tx time
85 */
86};
87
88void ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *);
89void ieee80211_rssadapt_input(struct ieee80211com *,
90 const struct ieee80211_node *, struct ieee80211_rssadapt *, int);
91void ieee80211_rssadapt_lower_rate(struct ieee80211com *,
92 const struct ieee80211_node *, struct ieee80211_rssadapt *,
93 const struct ieee80211_rssdesc *);
94void ieee80211_rssadapt_raise_rate(struct ieee80211com *,
95 struct ieee80211_rssadapt *, const struct ieee80211_rssdesc *);
96int ieee80211_rssadapt_choose(struct ieee80211_rssadapt *,
97 const struct ieee80211_rateset *, const struct ieee80211_frame *,
98 u_int, int, const char *, int);
99#ifdef IEEE80211_DEBUG
100extern int ieee80211_rssadapt_debug;
101#endif /* IEEE80211_DEBUG */
102
103#endif /* _NET80211_IEEE80211_RSSADAPT_H_ */