1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* OsmocomBB <-> SDR connection bridge
* TDMA scheduler: handlers for DL / UL bursts on logical channels
*
* (C) 2018 by Vadim Yanitskiy <axilirator@gmail.com>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <errno.h>
#include <stdint.h>
#include <stdbool.h>
#include "scheduler.h"
#include "sched_trx.h"
static const uint8_t tch_h0_traffic_block_map[3][4] = {
/* B0(0,2,4,6), B1(4,6,8,10), B2(8,10,0,2) */
{ 0, 2, 4, 6 },
{ 4, 6, 8, 10 },
{ 8, 10, 0, 2 },
};
static const uint8_t tch_h1_traffic_block_map[3][4] = {
/* B0(1,3,5,7), B1(5,7,9,11), B2(9,11,1,3) */
{ 1, 3, 5, 7 },
{ 5, 7, 9, 11 },
{ 9, 11, 1, 3 },
};
static const uint8_t tch_h0_dl_facch_block_map[3][6] = {
/* B0(4,6,8,10,13,15), B1(13,15,17,19,21,23), B2(21,23,0,2,4,6) */
{ 4, 6, 8, 10, 13, 15 },
{ 13, 15, 17, 19, 21, 23 },
{ 21, 23, 0, 2, 4, 6 },
};
static const uint8_t tch_h0_ul_facch_block_map[3][6] = {
/* B0(0,2,4,6,8,10), B1(8,10,13,15,17,19), B2(17,19,21,23,0,2) */
{ 0, 2, 4, 6, 8, 10 },
{ 8, 10, 13, 15, 17, 19 },
{ 17, 19, 21, 23, 0, 2 },
};
static const uint8_t tch_h1_dl_facch_block_map[3][6] = {
/* B0(5,7,9,11,14,16), B1(14,16,18,20,22,24), B2(22,24,1,3,5,7) */
{ 5, 7, 9, 11, 14, 16 },
{ 14, 16, 18, 20, 22, 24 },
{ 22, 24, 1, 3, 5, 7 },
};
const uint8_t tch_h1_ul_facch_block_map[3][6] = {
/* B0(1,3,5,7,9,11), B1(9,11,14,16,18,20), B2(18,20,22,24,1,3) */
{ 1, 3, 5, 7, 9, 11 },
{ 9, 11, 14, 16, 18, 20 },
{ 18, 20, 22, 24, 1, 3 },
};
/**
* Can a TCH/H block transmission be initiated / finished
* on a given frame number and a given channel type?
*
* See GSM 05.02, clause 7, table 1
*
* @param chan channel type (TRXC_TCHH_0 or TRXC_TCHH_1)
* @param fn the current frame number
* @param ul Uplink or Downlink?
* @param facch FACCH/H or traffic?
* @param start init or end of transmission?
* @return true (yes) or false (no)
*/
bool sched_tchh_block_map_fn(enum trx_lchan_type chan,
uint32_t fn, bool ul, bool facch, bool start)
{
uint8_t fn_mf;
int i = 0;
/* Just to be sure */
OSMO_ASSERT(chan == TRXC_TCHH_0 || chan == TRXC_TCHH_1);
/* Calculate a modulo */
fn_mf = facch ? (fn % 26) : (fn % 13);
#define MAP_GET_POS(map) \
(start ? 0 : ARRAY_SIZE(map[i]) - 1)
#define BLOCK_MAP_FN(map) \
do { \
if (map[i][MAP_GET_POS(map)] == fn_mf) \
return true; \
} while (++i < ARRAY_SIZE(map))
/* Choose a proper block map */
if (facch) {
if (ul) {
if (chan == TRXC_TCHH_0)
BLOCK_MAP_FN(tch_h0_ul_facch_block_map);
else
BLOCK_MAP_FN(tch_h1_ul_facch_block_map);
} else {
if (chan == TRXC_TCHH_0)
BLOCK_MAP_FN(tch_h0_dl_facch_block_map);
else
BLOCK_MAP_FN(tch_h1_dl_facch_block_map);
}
} else {
if (chan == TRXC_TCHH_0)
BLOCK_MAP_FN(tch_h0_traffic_block_map);
else
BLOCK_MAP_FN(tch_h1_traffic_block_map);
}
return false;
}
/**
* Calculates a frame number of the first burst
* using given frame number of the last burst.
*
* See GSM 05.02, clause 7, table 1
*
* @param chan channel type (TRXC_TCHH_0 or TRXC_TCHH_1)
* @param last_fn frame number of the last burst
* @param facch FACCH/H or traffic?
* @return either frame number of the first burst,
* or fn=last_fn if calculation failed
*/
uint32_t sched_tchh_block_dl_first_fn(enum trx_lchan_type chan,
uint32_t last_fn, bool facch)
{
uint8_t fn_mf, fn_diff;
int i = 0;
/* Just to be sure */
OSMO_ASSERT(chan == TRXC_TCHH_0 || chan == TRXC_TCHH_1);
/* Calculate a modulo */
fn_mf = facch ? (last_fn % 26) : (last_fn % 13);
#define BLOCK_FIRST_FN(map) \
do { \
if (map[i][ARRAY_SIZE(map[i]) - 1] == fn_mf) { \
fn_diff = TDMA_FN_DIFF(fn_mf, map[i][0]); \
return TDMA_FN_SUB(last_fn, fn_diff); \
} \
} while (++i < ARRAY_SIZE(map))
/* Choose a proper block map */
if (facch) {
if (chan == TRXC_TCHH_0)
BLOCK_FIRST_FN(tch_h0_dl_facch_block_map);
else
BLOCK_FIRST_FN(tch_h1_dl_facch_block_map);
} else {
if (chan == TRXC_TCHH_0)
BLOCK_FIRST_FN(tch_h0_traffic_block_map);
else
BLOCK_FIRST_FN(tch_h1_traffic_block_map);
}
LOGP(DSCHD, LOGL_ERROR, "Failed to calculate TDMA "
"frame number of the first burst of %s block, "
"using the current fn=%u\n", facch ?
"FACCH/H" : "TCH/H", last_fn);
/* Couldn't calculate the first fn, return the last */
return last_fn;
}
|
