/*! \defgroup gsm0502 GSM 05.02 / 3GPP TS 45.002 * @{ * \file gsm0502.h */ #pragma once #include #include #include /* 4.3.3 TDMA frame number : constants and modular arithmetic */ #define GSM_TDMA_FN_DURATION_nS 4615384 /* in 1e−9 seconds (approx) */ #define GSM_TDMA_FN_DURATION_uS 4615 /* in 1e-6 seconds (approx) */ #define GSM_TDMA_SUPERFRAME (26 * 51) #define GSM_TDMA_HYPERFRAME (2048 * GSM_TDMA_SUPERFRAME) /*! Return the sum of two specified TDMA frame numbers (summation) */ #define GSM_TDMA_FN_SUM(a, b) \ (((a) + (b)) % GSM_TDMA_HYPERFRAME) /*! Return the difference of two specified TDMA frame numbers (subtraction) */ #define GSM_TDMA_FN_SUB(a, b) \ (((a) + GSM_TDMA_HYPERFRAME - (b)) % GSM_TDMA_HYPERFRAME) /*! Return the *minimum* difference of two specified TDMA frame numbers (distance) */ #define GSM_TDMA_FN_DIFF(a, b) \ OSMO_MIN(GSM_TDMA_FN_SUB(a, b), GSM_TDMA_FN_SUB(b, a)) /*! Increment the given TDMA frame number by 1 and return the result (like ++fn) */ #define GSM_TDMA_FN_INC(fn) \ ((fn) = GSM_TDMA_FN_SUM((fn), 1)) /*! Decrement the given TDMA frame number by 1 and return the result (like --fn) */ #define GSM_TDMA_FN_DEC(fn) \ ((fn) = GSM_TDMA_FN_SUB((fn), 1)) /* 5.2.3.1 Normal burst for GMSK (1 bit per symbol) */ #define GSM_NBITS_NB_GMSK_TAIL 3 #define GSM_NBITS_NB_GMSK_PAYLOAD (2 * 58) #define GSM_NBITS_NB_GMSK_TRAIN_SEQ 26 #define GSM_NBITS_NB_GMSK_BURST 148 /* without guard period */ /* 5.2.3.3 Normal burst for 8-PSK (3 bits per symbol) */ #define GSM_NBITS_NB_8PSK_TAIL (GSM_NBITS_NB_GMSK_TAIL * 3) #define GSM_NBITS_NB_8PSK_PAYLOAD (GSM_NBITS_NB_GMSK_PAYLOAD * 3) #define GSM_NBITS_NB_8PSK_TRAIN_SEQ (GSM_NBITS_NB_GMSK_TRAIN_SEQ * 3) #define GSM_NBITS_NB_8PSK_BURST (GSM_NBITS_NB_GMSK_BURST * 3) /* 5.2.5 Synchronization burst (also GMSK) */ #define GSM_NBITS_SB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL #define GSM_NBITS_SB_GMSK_PAYLOAD (2 * 39) #define GSM_NBITS_SB_GMSK_ETRAIN_SEQ 64 #define GSM_NBITS_SB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST /* 5.2.6 Dummy burst (also GMSK) */ #define GSM_NBITS_DB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL #define GSM_NBITS_DB_GMSK_MIXED 142 #define GSM_NBITS_DB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST /* 5.2.7 Access burst (also GMSK) */ #define GSM_NBITS_AB_GMSK_ETAIL 8 #define GSM_NBITS_AB_GMSK_SYNCH_SEQ 41 #define GSM_NBITS_AB_GMSK_PAYLOAD 36 #define GSM_NBITS_AB_GMSK_TAIL GSM_NBITS_NB_GMSK_TAIL #define GSM_NBITS_AB_GMSK_BURST GSM_NBITS_NB_GMSK_BURST /*! Compare the given TDMA FNs, taking the wrapping into account. * \param[in] fn1 First TDMA Fn value to compare. * \param[in] fn2 Second TDMA Fn value to compare. * \returns similarly to memcmp(), -1 if fn1 goes before fn2; * 0 if fn1 equals fn2; * 1 if fn1 goes after fn2. */ static inline int gsm0502_fncmp(uint32_t fn1, uint32_t fn2) { const uint32_t thresh = GSM_TDMA_HYPERFRAME / 2; if (fn1 == fn2) return 0; if ((fn1 < fn2 && (fn2 - fn1) < thresh) || (fn1 > fn2 && (fn1 - fn2) > thresh)) return -1; return 1; } /* Table 5 Clause 7 TS 05.02 */ static inline unsigned int gsm0502_get_n_pag_blocks(const struct gsm48_control_channel_descr *chan_desc) { if (chan_desc->ccch_conf == RSL_BCCH_CCCH_CONF_1_C) return 3 - chan_desc->bs_ag_blks_res; else return 9 - chan_desc->bs_ag_blks_res; } /* Chapter 6.5.2 of TS 05.02 */ static inline unsigned int gsm0502_get_ccch_group(uint64_t imsi, unsigned int bs_cc_chans, unsigned int n_pag_blocks) { return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) / n_pag_blocks; } /* Chapter 6.5.2 of TS 05.02 */ static inline unsigned int gsm0502_get_paging_group(uint64_t imsi, unsigned int bs_cc_chans, int n_pag_blocks) { return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) % n_pag_blocks; } unsigned int gsm0502_calc_paging_group(const struct gsm48_control_channel_descr *chan_desc, uint64_t imsi); enum gsm0502_fn_remap_channel { FN_REMAP_TCH_F, FN_REMAP_TCH_H0, FN_REMAP_TCH_H1, FN_REMAP_FACCH_F, FN_REMAP_FACCH_H0, FN_REMAP_FACCH_H1, FN_REMAP_MAX, }; uint32_t gsm0502_fn_remap(uint32_t fn, enum gsm0502_fn_remap_channel channel); uint16_t gsm0502_hop_seq_gen(const struct gsm_time *t, uint8_t hsn, uint8_t maio, size_t n, const uint16_t *ma); int gsm0502_fn2ccch_block(uint32_t fn); /*! @} */