diff options
Diffstat (limited to 'gsm-receiver/src/lib/decoder')
| -rw-r--r-- | gsm-receiver/src/lib/decoder/gsmstack.c | 128 | ||||
| -rw-r--r-- | gsm-receiver/src/lib/decoder/gsmstack.h | 24 |
2 files changed, 141 insertions, 11 deletions
diff --git a/gsm-receiver/src/lib/decoder/gsmstack.c b/gsm-receiver/src/lib/decoder/gsmstack.c index 2bdbf12..3766268 100644 --- a/gsm-receiver/src/lib/decoder/gsmstack.c +++ b/gsm-receiver/src/lib/decoder/gsmstack.c @@ -24,17 +24,6 @@ static const int USEFUL_BITS = 142; -enum BURST_TYPE { - UNKNOWN, - FCCH, - PARTIAL_SCH, //successful correlation, but missing data ^ - SCH, - CTS_SCH, - COMPACT_SCH, - NORMAL, - DUMMY, - ACCESS -}; static void out_gsmdecode(char type, int arfcn, int ts, int fn, char *data, int len); /* encode a decoded burst (1 bit per byte) into 8-bit-per-byte */ @@ -81,6 +70,123 @@ diff_decode(char *dst, char *src, int len) } #endif +/* TODO: handle mapping in a more elegant way or simplify the function */ + +uint8_t +get_chan_type(enum TIMESLOT_TYPE type, int fn, uint8_t *ss) +{ + uint8_t chan_type = GSMTAP_CHANNEL_BCCH; + *ss = 0; + int mf51 = fn % 51; + + if(type == TST_FCCH_SCH_BCCH_CCCH_SDCCH4) + { + if(mf51 == 22) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4; + *ss = 0; + } + else if(mf51 == 26) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4; + *ss = 1; + } + else if(mf51 == 32) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4; + *ss = 2; + } + else if(mf51 == 36) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4; + *ss = 3; + } + else if(mf51 == 42) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 2 : 0; + } + else if(mf51 == 46) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH4 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 3 : 1; + } + } + else if(type == TST_FCCH_SCH_BCCH_CCCH) + { + if(mf51 != 2) /* BCCH */ + { + chan_type = GSMTAP_CHANNEL_CCCH; + *ss = 0; + } + } + else if(type == TST_SDCCH8) + { + if(mf51 == 0) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 0; + } + else if(mf51 == 4) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 1; + } + else if(mf51 == 8) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 2; + } + else if(mf51 == 12) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 3; + } + else if(mf51 == 16) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 4; + } + else if(mf51 == 20) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 5; + } + else if(mf51 == 24) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 6; + } + else if(mf51 == 28) /* SDCCH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8; + *ss = 7; + } + else if(mf51 == 32) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 4 : 0; + } + else if(mf51 == 36) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 5 : 1; + } + else if(mf51 == 40) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 6 : 2; + } + else if(mf51 == 44) /* SAACH */ + { + chan_type = GSMTAP_CHANNEL_SDCCH8 | GSMTAP_CHANNEL_ACCH; + *ss = ((fn % 102) > 51) ? 7 : 3; + } + } + + return chan_type; +} + /* * Initialize a new GSMSTACK context. */ diff --git a/gsm-receiver/src/lib/decoder/gsmstack.h b/gsm-receiver/src/lib/decoder/gsmstack.h index 62427d2..ea84d60 100644 --- a/gsm-receiver/src/lib/decoder/gsmstack.h +++ b/gsm-receiver/src/lib/decoder/gsmstack.h @@ -9,10 +9,34 @@ extern "C" { #include <linux/if_ether.h> #include "interleave.h" +enum BURST_TYPE { + UNKNOWN = 0, + FCCH, + PARTIAL_SCH, //successful correlation, but missing data ^ + SCH, + CTS_SCH, + COMPACT_SCH, + NORMAL, + DUMMY, + ACCESS +}; + +enum TIMESLOT_TYPE { + TST_UNKNOWN = 0, + TST_OFF, /* timeslot is not decoded */ + TST_FCCH_SCH_BCCH_CCCH_SDCCH4, + TST_FCCH_SCH_BCCH_CCCH, + TST_SDCCH8, + TST_TCHF +}; + struct gs_ts_ctx { /* FIXME: later do this per each ts per each arfcn */ unsigned char burst[4 * 58 * 2]; + unsigned char burst2[8 * 58 * 2]; /* buffer for FACCH on TCH */ int burst_count; + int burst_count2; /* counter for FACCH on TCH */ + enum TIMESLOT_TYPE type; }; typedef struct |