From 4c0ce874481a4ec895bf55211aa53ff190572e4f Mon Sep 17 00:00:00 2001 From: Dieter Spaar Date: Thu, 29 Jul 2010 21:24:18 +0200 Subject: Add SACCH support for TCH/F --- gsm-receiver/src/lib/decoder/gsmstack.c | 8 +++++- gsm-receiver/src/lib/gsm_constants.h | 2 +- gsm-receiver/src/lib/gsm_receiver_cf.cc | 44 +++++++++++++++++++++++---------- 3 files changed, 39 insertions(+), 15 deletions(-) (limited to 'gsm-receiver/src') diff --git a/gsm-receiver/src/lib/decoder/gsmstack.c b/gsm-receiver/src/lib/decoder/gsmstack.c index e5734b9..c1d967e 100644 --- a/gsm-receiver/src/lib/decoder/gsmstack.c +++ b/gsm-receiver/src/lib/decoder/gsmstack.c @@ -183,6 +183,9 @@ get_chan_type(enum TIMESLOT_TYPE type, int fn, uint8_t *ss) *ss = ((fn % 102) > 51) ? 7 : 3; } } + else if (type == TST_TCHF) { + chan_type = GSMTAP_CHANNEL_TCH_F | GSMTAP_CHANNEL_ACCH; + } return chan_type; } @@ -239,9 +242,12 @@ GS_process(GS_CTX *ctx, int ts, int type, const unsigned char *src, int fn, int memset(ctx->msg, 0, sizeof(ctx->msg)); - if (ts_ctx->type == TST_TCHF && type == NORMAL) { + if (ts_ctx->type == TST_TCHF && type == NORMAL && + (fn % 26) != 12 && (fn % 26) != 25) { /* Dieter: we came here because the burst might contain FACCH bits */ ctx->fn = fn; + + /* get burst index to TCH bursts only */ ts_ctx->burst_count2 = fn % 26; if (ts_ctx->burst_count2 >= 12) diff --git a/gsm-receiver/src/lib/gsm_constants.h b/gsm-receiver/src/lib/gsm_constants.h index b6cef2f..f6048f2 100644 --- a/gsm-receiver/src/lib/gsm_constants.h +++ b/gsm-receiver/src/lib/gsm_constants.h @@ -54,7 +54,7 @@ const unsigned BCCH_FRAMES[] = {2, 3, 4, 5}; //!!the receiver shouldn't /* Dieter: xxxx_FIRST marks the first burst of a frame */ const unsigned TEST_CCH_FRAMES[] = {2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 25, 26, 27, 28, 29, 32, 33, 34, 35, 36, 37, 38, 39, 42, 43, 44, 45, 46, 47, 48, 49}; const unsigned TEST_CCH_FIRST[] = {1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0}; -const unsigned TRAFFIC_CHANNEL_F[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}; +const unsigned TRAFFIC_CHANNEL_F[] = {0, 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}; /* 12, 25: SACCH or IDLE */ const unsigned TEST51[] = {0, 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}; const unsigned SDCCH_SACCH_8_FRAMES[] = {0, 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}; const unsigned SDCCH_SACCH_8_FIRST[] = {1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0}; diff --git a/gsm-receiver/src/lib/gsm_receiver_cf.cc b/gsm-receiver/src/lib/gsm_receiver_cf.cc index 9feabef..2660bdc 100644 --- a/gsm-receiver/src/lib/gsm_receiver_cf.cc +++ b/gsm-receiver/src/lib/gsm_receiver_cf.cc @@ -187,20 +187,30 @@ void gsm_receiver_cf::process_normal_burst(burst_counter burst_nr, const unsigne #endif decrypt(burst_binary, d_KC, decrypted_data, burst_nr.get_frame_nr_mod()); - int i; - for (i = 0; i< 148; i++) - decrypted_data_float[i] = decrypted_data[i]; - - GSM::Time time(burst_nr.get_frame_nr(), ts); - GSM::RxBurst rxbrst(decrypted_data_float, time); - if (ts - TIMESLOT1 >= 0 && ts - TIMESLOT1 < N_TCH_DECODER) { - if ( d_tch_decoder[ts - TIMESLOT1]->processBurst( rxbrst ) == true) { - fwrite(d_tch_decoder[ts - TIMESLOT1]->get_voice_frame(), 1 , 33, d_gsm_file); - } - else if (rxbrst.Hl() || rxbrst.Hu()) { - /* Stolen bits are set, might be FACCH */ - GS_process(&d_gs_ctx, TIMESLOT0 + ts, NORMAL, &decrypted_data[3], burst_nr.get_frame_nr(), first_burst); + if (burst_nr.get_t2() == 12 || burst_nr.get_t2() == 25) { /* SACCH of Full Rate TCH */ + if (ts % 2 == 0) /* SACH position and start depends on the timeslot */ + first_burst = (burst_nr.get_frame_nr() % 104) == (12 + 26 * (ts / 2)); + else + first_burst = (burst_nr.get_frame_nr() % 104) == (25 + 26 * ((ts - 1) / 2)); +#if 0 /* dump cipher, plain and keystream bits */ + dump_bits(burst_binary, decrypted_data, burst_nr, first_burst); +#endif + GS_process(&d_gs_ctx, TIMESLOT0 + ts, NORMAL, &decrypted_data[3], burst_nr.get_frame_nr(), first_burst); + } else { + int i; + for (i = 0; i< 148; i++) + decrypted_data_float[i] = decrypted_data[i]; + + GSM::Time time(burst_nr.get_frame_nr(), ts); + GSM::RxBurst rxbrst(decrypted_data_float, time); + if (ts - TIMESLOT1 >= 0 && ts - TIMESLOT1 < N_TCH_DECODER) { + if ( d_tch_decoder[ts - TIMESLOT1]->processBurst( rxbrst ) == true) + fwrite(d_tch_decoder[ts - TIMESLOT1]->get_voice_frame(), 1 , 33, d_gsm_file); + else if(rxbrst.Hl() || rxbrst.Hu()) { + /* Stolen bits are set, might be FACCH */ + GS_process(&d_gs_ctx, TIMESLOT0 + ts, NORMAL, &decrypted_data[3], burst_nr.get_frame_nr(), first_burst); } + } } } @@ -249,6 +259,14 @@ void gsm_receiver_cf::configure_receiver() if (d_gs_ctx.ts_ctx[ts].type == TST_TCHF) { d_channel_conf.set_multiframe_type(ts, multiframe_26); d_channel_conf.set_burst_types(ts, TRAFFIC_CHANNEL_F, sizeof(TRAFFIC_CHANNEL_F) / sizeof(unsigned), dummy_or_normal); + /* SACH position depends on the timeslot */ + if (ts % 2 == 0) { + d_channel_conf.set_single_burst_type(ts, 12, normal_burst); /* SACCH for even timeslots */ + d_channel_conf.set_single_burst_type(ts, 25, empty); /* IDLE for even timeslots */ + } else { + d_channel_conf.set_single_burst_type(ts, 12, empty); /* IDLE for odd timeslots */ + d_channel_conf.set_single_burst_type(ts, 25, normal_burst); /* SACCH for odd timeslots */ + } } else if (d_gs_ctx.ts_ctx[ts].type == TST_SDCCH8) { d_channel_conf.set_multiframe_type(ts, multiframe_51); -- cgit v1.2.3