libosmogsm  1.10.0.56-fc03.202412192026
Osmocom GSM library
gsm0502.h
Go to the documentation of this file.
1 
6 #pragma once
7 
8 #include <stdint.h>
9 
12 
13 /* 4.3.3 TDMA frame number : constants and modular arithmetic */
14 #define GSM_TDMA_FN_DURATION_nS 4615384 /* in 1e−9 seconds (approx) */
15 #define GSM_TDMA_FN_DURATION_uS 4615 /* in 1e-6 seconds (approx) */
16 
17 #define GSM_TDMA_SUPERFRAME (26 * 51)
18 #define GSM_TDMA_HYPERFRAME (2048 * GSM_TDMA_SUPERFRAME)
19 
21 #define GSM_TDMA_FN_SUM(a, b) \
22  (((a) + (b)) % GSM_TDMA_HYPERFRAME)
24 #define GSM_TDMA_FN_SUB(a, b) \
25  (((a) + GSM_TDMA_HYPERFRAME - (b)) % GSM_TDMA_HYPERFRAME)
27 #define GSM_TDMA_FN_DIFF(a, b) \
28  OSMO_MIN(GSM_TDMA_FN_SUB(a, b), GSM_TDMA_FN_SUB(b, a))
29 
31 #define GSM_TDMA_FN_INC(fn) \
32  ((fn) = GSM_TDMA_FN_SUM((fn), 1))
34 #define GSM_TDMA_FN_DEC(fn) \
35  ((fn) = GSM_TDMA_FN_SUB((fn), 1))
36 
37 /* 5.2.3.1 Normal burst for GMSK (1 bit per symbol) */
38 #define GSM_NBITS_NB_GMSK_TAIL 3
39 #define GSM_NBITS_NB_GMSK_PAYLOAD (2 * 58)
40 #define GSM_NBITS_NB_GMSK_TRAIN_SEQ 26
41 #define GSM_NBITS_NB_GMSK_BURST 148 /* without guard period */
42 
43 /* 5.2.3.3 Normal burst for 8-PSK (3 bits per symbol) */
44 #define GSM_NBITS_NB_8PSK_TAIL (GSM_NBITS_NB_GMSK_TAIL * 3)
45 #define GSM_NBITS_NB_8PSK_PAYLOAD (GSM_NBITS_NB_GMSK_PAYLOAD * 3)
46 #define GSM_NBITS_NB_8PSK_TRAIN_SEQ (GSM_NBITS_NB_GMSK_TRAIN_SEQ * 3)
47 #define GSM_NBITS_NB_8PSK_BURST (GSM_NBITS_NB_GMSK_BURST * 3)
48 
49 /* 5.2.5 Synchronization burst (also GMSK) */
50 #define GSM_NBITS_SB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL
51 #define GSM_NBITS_SB_GMSK_PAYLOAD (2 * 39)
52 #define GSM_NBITS_SB_GMSK_ETRAIN_SEQ 64
53 #define GSM_NBITS_SB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST
54 
55 /* 5.2.6 Dummy burst (also GMSK) */
56 #define GSM_NBITS_DB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL
57 #define GSM_NBITS_DB_GMSK_MIXED 142
58 #define GSM_NBITS_DB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST
59 
60 /* 5.2.7 Access burst (also GMSK) */
61 #define GSM_NBITS_AB_GMSK_ETAIL 8
62 #define GSM_NBITS_AB_GMSK_SYNCH_SEQ 41
63 #define GSM_NBITS_AB_GMSK_PAYLOAD 36
64 #define GSM_NBITS_AB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL
65 #define GSM_NBITS_AB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST
66 
73 static inline int gsm0502_fncmp(uint32_t fn1, uint32_t fn2)
74 {
75  const uint32_t thresh = GSM_TDMA_HYPERFRAME / 2;
76 
77  if (fn1 == fn2)
78  return 0;
79  if ((fn1 < fn2 && (fn2 - fn1) < thresh) ||
80  (fn1 > fn2 && (fn1 - fn2) > thresh))
81  return -1;
82 
83  return 1;
84 }
85 
86 /* Table 5 Clause 7 TS 05.02 */
87 static inline unsigned int
89 {
90  if (chan_desc->ccch_conf == RSL_BCCH_CCCH_CONF_1_C)
91  return 3 - chan_desc->bs_ag_blks_res;
92  else
93  return 9 - chan_desc->bs_ag_blks_res;
94 }
95 
96 /* Chapter 6.5.2 of TS 05.02 */
97 static inline unsigned int
98 gsm0502_get_ccch_group(uint64_t imsi, unsigned int bs_cc_chans,
99  unsigned int n_pag_blocks)
100 {
101  return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) / n_pag_blocks;
102 }
103 
104 /* Chapter 6.5.2 of TS 05.02 */
105 static inline unsigned int
106 gsm0502_get_paging_group(uint64_t imsi, unsigned int bs_cc_chans,
107  int n_pag_blocks)
108 {
109  return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) % n_pag_blocks;
110 }
111 
112 unsigned int
114 
123 };
124 
125 uint32_t gsm0502_fn_remap(uint32_t fn, enum gsm0502_fn_remap_channel channel);
126 
127 uint16_t gsm0502_hop_seq_gen(const struct gsm_time *t,
128  uint8_t hsn, uint8_t maio,
129  size_t n, const uint16_t *ma);
130 
131 int gsm0502_fn2ccch_block(uint32_t fn);
132 
write Write running configuration to or terminal n Write configuration to the copy running config startup Copy configuration n Copy running config to n Copy running config to startup write Write running configuration to or terminal n Write to terminal n
static unsigned int gsm0502_get_ccch_group(uint64_t imsi, unsigned int bs_cc_chans, unsigned int n_pag_blocks)
Definition: gsm0502.h:98
int gsm0502_fn2ccch_block(uint32_t fn)
Calculate CCCH block number from the given TDMA frame number.
Definition: gsm0502.c:294
uint32_t gsm0502_fn_remap(uint32_t fn, enum gsm0502_fn_remap_channel channel)
Calculate the frame number of the beginning of a block.
Definition: gsm0502.c:177
#define GSM_TDMA_HYPERFRAME
Definition: gsm0502.h:18
static unsigned int gsm0502_get_paging_group(uint64_t imsi, unsigned int bs_cc_chans, int n_pag_blocks)
Definition: gsm0502.h:106
uint16_t gsm0502_hop_seq_gen(const struct gsm_time *t, uint8_t hsn, uint8_t maio, size_t n, const uint16_t *ma)
Hopping sequence generation as per 3GPP TS 45.002, section 6.2.3.
Definition: gsm0502.c:230
static unsigned int gsm0502_get_n_pag_blocks(const struct gsm48_control_channel_descr *chan_desc)
Definition: gsm0502.h:88
unsigned int gsm0502_calc_paging_group(const struct gsm48_control_channel_descr *chan_desc, uint64_t imsi)
Definition: gsm0502.c:37
static int gsm0502_fncmp(uint32_t fn1, uint32_t fn2)
Compare the given TDMA FNs, taking the wrapping into account.
Definition: gsm0502.h:73
gsm0502_fn_remap_channel
Definition: gsm0502.h:115
@ FN_REMAP_TCH_H0
Definition: gsm0502.h:117
@ FN_REMAP_TCH_H1
Definition: gsm0502.h:118
@ FN_REMAP_MAX
Definition: gsm0502.h:122
@ FN_REMAP_FACCH_F
Definition: gsm0502.h:119
@ FN_REMAP_FACCH_H1
Definition: gsm0502.h:121
@ FN_REMAP_TCH_F
Definition: gsm0502.h:116
@ FN_REMAP_FACCH_H0
Definition: gsm0502.h:120
#define RSL_BCCH_CCCH_CONF_1_C
Definition: gsm_08_58.h:727
GSM TS 04.08 definitions.
struct gsm48_chan_desc chan_desc
Definition: gsm_04_08.h:0
GSM Radio Signalling Link messages on the A-bis interface.
Definition: gsm_04_08.h:992
Definition: gsm_utils.h:41