diff options
Diffstat (limited to 'src/osmo-bts-litecell15/tch.c')
| -rw-r--r-- | src/osmo-bts-litecell15/tch.c | 131 |
1 files changed, 116 insertions, 15 deletions
diff --git a/src/osmo-bts-litecell15/tch.c b/src/osmo-bts-litecell15/tch.c index 245c19a3..db16209d 100644 --- a/src/osmo-bts-litecell15/tch.c +++ b/src/osmo-bts-litecell15/tch.c @@ -481,7 +481,66 @@ err_payload_match: return -EINVAL; } -struct msgb *gen_empty_tch_msg(struct gsm_lchan *lchan) +static inline bool fn_chk(uint8_t *t, uint32_t fn) +{ + uint8_t i; + for (i = 0; i < ARRAY_SIZE(t); i++) + if (fn % 104 == t[i]) + return false; + return true; +} + +static bool dtx_sched_optional(struct gsm_lchan *lchan, uint32_t fn) +{ + /* 3GPP TS 45.008 ยง 8.3 */ + uint8_t f[] = { 52, 53, 54, 55, 56, 57, 58, 59 }, + h0[] = { 0, 2, 4, 6, 52, 54, 56, 58 }, + h1[] = { 14, 16, 18, 20, 66, 68, 70, 72 }; + if (lchan->tch_mode == GSM48_CMODE_SPEECH_V1) { + if (lchan->type == GSM_LCHAN_TCH_F) + return fn_chk(f, fn); + else + return fn_chk(lchan->nr ? h1 : h0, fn); + } + return false; +} + +static bool repeat_last_sid(struct gsm_lchan *lchan, struct msgb *msg) +{ + GsmL1_Prim_t *l1p; + GsmL1_PhDataReq_t *data_req; + GsmL1_MsgUnitParam_t *msu_param; + uint8_t *l1_payload; + + l1p = msgb_l1prim(msg); + data_req = &l1p->u.phDataReq; + msu_param = &data_req->msgUnitParam; + l1_payload = &msu_param->u8Buffer[1]; + + if (lchan->tch.last_sid.len) { + memcpy(l1_payload, lchan->tch.last_sid.buf, + lchan->tch.last_sid.len); + msu_param->u8Size = lchan->tch.last_sid.len + 1; + return true; + } + return false; +} + +/* store the last SID frame in lchan context */ +void save_last_sid(struct gsm_lchan *lchan, uint8_t *l1_payload, size_t length, + uint32_t fn, bool update) +{ + size_t copy_len = OSMO_MIN(length + 1, + ARRAY_SIZE(lchan->tch.last_sid.buf)); + + lchan->tch.last_sid.len = copy_len; + lchan->tch.last_sid.fn = fn; + lchan->tch.last_sid.is_update = update; + + memcpy(lchan->tch.last_sid.buf, l1_payload, copy_len); +} + +struct msgb *gen_empty_tch_msg(struct gsm_lchan *lchan, uint32_t fn) { struct msgb *msg; GsmL1_Prim_t *l1p; @@ -503,21 +562,63 @@ struct msgb *gen_empty_tch_msg(struct gsm_lchan *lchan) switch (lchan->tch_mode) { case GSM48_CMODE_SPEECH_AMR: *payload_type = GsmL1_TchPlType_Amr; - if (lchan->tch.last_sid.len) { - memcpy(l1_payload, lchan->tch.last_sid.buf, - lchan->tch.last_sid.len); - msu_param->u8Size = lchan->tch.last_sid.len+1; + /* according to 3GPP TS 26.093 A.5.1.1: */ + if (lchan->tch.last_sid.is_update) { + /* SID UPDATE should be repeated every 8th frame */ + if (fn - lchan->tch.last_sid.fn < 7) { + msgb_free(msg); + return NULL; + } } else { - /* FIXME: decide if we should send SPEECH_BAD or - * SID_BAD */ -#if 0 - *payload_type = GsmL1_TchPlType_Amr_SidBad; - memset(l1_payload, 0xFF, 5); - msu_param->u8Size = 5 + 3; -#else - /* send an all-zero SID */ - msu_param->u8Size = 8; -#endif + /* 3rd frame after SID FIRST should be SID UPDATE */ + if (fn - lchan->tch.last_sid.fn < 3) { + msgb_free(msg); + return NULL; + } + } + if (repeat_last_sid(lchan, msg)) + return msg; + else { + LOGP(DL1C, LOGL_NOTICE, "Have to send AMR frame on TCH " + "(FN=%u) but SID buffer is empty - sent NO_DATA\n", + fn); + osmo_amr_rtp_enc(l1_payload, 0, AMR_NO_DATA, + AMR_GOOD); + return msg; + } + break; + case GSM48_CMODE_SPEECH_V1: + if (lchan->type == GSM_LCHAN_TCH_F) + *payload_type = GsmL1_TchPlType_Fr; + else + *payload_type = GsmL1_TchPlType_Hr; + /* unlike AMR, FR & HR schedued based on absolute FN value */ + if (dtx_sched_optional(lchan, fn)) { + msgb_free(msg); + return NULL; + } + if (repeat_last_sid(lchan, msg)) + return msg; + else { + LOGP(DL1C, LOGL_NOTICE, "Have to send V1 frame on TCH " + "(FN=%u) but SID buffer is empty - sent nothing\n", + fn); + return NULL; + } + break; + case GSM48_CMODE_SPEECH_EFR: + *payload_type = GsmL1_TchPlType_Efr; + if (dtx_sched_optional(lchan, fn)) { + msgb_free(msg); + return NULL; + } + if (repeat_last_sid(lchan, msg)) + return msg; + else { + LOGP(DL1C, LOGL_NOTICE, "Have to send EFR frame on TCH " + "(FN=%u) but SID buffer is empty - sent nothing\n", + fn); + return NULL; } break; default: |