master
1/* $NetBSD: ieee80211_rssadapt.h,v 1.9 2016/04/08 14:30:47 roy 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 *
15 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
18 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
19 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
21 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
26 * OF SUCH DAMAGE.
27 */
28
29#ifndef _NET80211_IEEE80211_RSSADAPT_H_
30#define _NET80211_IEEE80211_RSSADAPT_H_
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
49struct ieee80211_rssadapt_expavgctl {
50 /* RSS threshold decay. */
51 u_int rc_decay_denom;
52 u_int rc_decay_old;
53 /* RSS threshold update. */
54 u_int rc_thresh_denom;
55 u_int rc_thresh_old;
56 /* RSS average update. */
57 u_int rc_avgrssi_denom;
58 u_int rc_avgrssi_old;
59};
60
61struct ieee80211_rssadapt {
62 /* exponential average RSSI << 8 */
63 u_int16_t ra_avg_rssi;
64 /* Tx failures in this update interval */
65 u_int32_t ra_nfail;
66 /* Tx successes in this update interval */
67 u_int32_t ra_nok;
68 /* exponential average packets/second */
69 u_int32_t ra_pktrate;
70 /* RSSI threshold for each Tx rate */
71 u_int16_t ra_rate_thresh[IEEE80211_RSSADAPT_BKTS]
72 [IEEE80211_RATE_SIZE];
73 struct timeval ra_last_raise;
74 struct timeval ra_raise_interval;
75};
76
77/* Properties of a Tx packet, for link adaptation. */
78struct ieee80211_rssdesc {
79 u_int id_len; /* Tx packet length */
80 u_int id_rateidx; /* index into ni->ni_rates */
81 struct ieee80211_node *id_node; /* destination STA MAC */
82 u_int8_t id_rssi; /* destination STA avg RSS @
83 * Tx time
84 */
85};
86
87void ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *);
88void ieee80211_rssadapt_input(struct ieee80211com *, struct ieee80211_node *,
89 struct ieee80211_rssadapt *, int);
90void ieee80211_rssadapt_lower_rate(struct ieee80211com *,
91 struct ieee80211_node *, struct ieee80211_rssadapt *,
92 struct ieee80211_rssdesc *);
93void ieee80211_rssadapt_raise_rate(struct ieee80211com *,
94 struct ieee80211_rssadapt *, struct ieee80211_rssdesc *);
95int ieee80211_rssadapt_choose(struct ieee80211_rssadapt *,
96 struct ieee80211_rateset *, struct ieee80211_frame *, u_int, int,
97 const char *, int);
98#ifdef IEEE80211_DEBUG
99extern int ieee80211_rssadapt_debug;
100#endif /* IEEE80211_DEBUG */
101
102#endif /* !_NET80211_IEEE80211_RSSADAPT_H_ */