falconia has uploaded this change for review.
HRv1 codec: add support for TW-TS-002
OsmoBTS supports TW-TS-001 enhanced RTP format for FR and EFR codecs
since 2024, providing functional equivalent of GSM 08.60 TRAU-UL
output over IP physical transport. Now do the same with TW-TS-002,
IP equivalent of GSM 08.61 for HRv1 codec.
Only TCH UL path is affected; no changes are needed to TCH DL path
because existing RTP Rx handling for RFC 5993 also covers TW-TS-002.
Related: OS#6036
Change-Id: Icf11e43d4ce9df990d0e0a856d62d9ea11cb837c
---
M src/common/bts.c
M src/common/l1sap.c
2 files changed, 74 insertions(+), 7 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/50/41050/1
diff --git a/src/common/bts.c b/src/common/bts.c
index 282d730..73cb8a6 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -394,6 +394,7 @@
osmo_bts_set_feature(bts->features, BTS_FEAT_IPV6_NSVC);
osmo_bts_set_feature(bts->features, BTS_FEAT_PAGING_COORDINATION);
osmo_bts_set_feature(bts->features, BTS_FEAT_TWTS001);
+ osmo_bts_set_feature(bts->features, BTS_FEAT_TWTS002);
/* Maximum TA supported by the PHY (can be overridden by PHY specific code) */
bts->support.max_ta = MAX_TA_DEF;
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index e8453b8..d8754f6 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -2227,12 +2227,66 @@
}
}
+/* See Section 5.2 of RFC5993 and TW-TS-002 */
+enum super5993_ft {
+ FT_GOOD_SPEECH = 0,
+ FT_INVALID_SID = 1,
+ FT_GOOD_SID = 2,
+ FT_BFI_WITH_DATA = 6,
+ FT_NO_DATA = 7,
+};
+
+/* a helper function for emitting GSM-HR UL in TW-TS-002 format */
+static void send_rtp_twts002(struct gsm_lchan *lchan, uint32_t fn,
+ struct msgb *msg)
+{
+ enum super5993_ft ft;
+ uint8_t toc;
+ bool send_frame;
+
+ if (msg->len == GSM_HR_BYTES) {
+ switch (tch_ul_msg_sid(msg)) {
+ case OSMO_GSM631_SID_CLASS_SPEECH:
+ ft = tch_ul_msg_bfi(msg) ? FT_BFI_WITH_DATA
+ : FT_GOOD_SPEECH;
+ break;
+ case OSMO_GSM631_SID_CLASS_INVALID:
+ ft = FT_INVALID_SID;
+ break;
+ case OSMO_GSM631_SID_CLASS_VALID:
+ ft = tch_ul_msg_bfi(msg) ? FT_INVALID_SID : FT_GOOD_SID;
+ break;
+ default:
+ OSMO_ASSERT(0);
+ }
+ send_frame = true;
+ } else {
+ ft = FT_NO_DATA;
+ send_frame = false;
+ }
+ /* ToC octet of TW-TS-002 is an extension of RFC 5993 */
+ toc = ft << 4;
+ if (ft == FT_INVALID_SID)
+ toc |= 0x04; /* TW-TS-002 version 1.2.0 */
+ /* always set DTXd and TAF bits */
+ if (lchan->ts->trx->bts->dtxd)
+ toc |= 0x08;
+ if (fr_hr_efr_sid_position(lchan, fn))
+ toc |= 0x01;
+ if (send_frame) {
+ msgb_push_u8(msg, toc);
+ send_ul_rtp_packet(lchan, fn, msg->data, msg->len);
+ } else {
+ send_ul_rtp_packet(lchan, fn, &toc, 1);
+ }
+}
+
/* A helper function for l1sap_tch_ind(): handling BFI
*
* Please note that the msgb passed to this function is used only when
- * the CN asked the BSS to emit extended RTP formats (currently TW-TS-001,
- * later TW-TS-002 as well) that can indicate BFI along with deemed-bad
- * frame data bits, just like GSM 08.60 and 08.61 TRAU-UL frames.
+ * the CN asked the BSS to emit extended RTP formats of TW-TS-001 or
+ * TW-TS-002 that can indicate BFI along with deemed-bad frame data bits,
+ * just like GSM 08.60 and 08.61 TRAU-UL frames.
*/
static void tch_ul_bfi_handler(struct gsm_lchan *lchan,
const struct gsm_time *g_time, struct msgb *msg)
@@ -2255,6 +2309,14 @@
return;
}
+ /* Ditto for TCH/HS and TW-TS-002. */
+ if ((lchan->abis_ip.rtp_extensions & OSMO_RTP_EXT_TWTS002) &&
+ lchan->type == GSM_LCHAN_TCH_H &&
+ lchan->tch_mode == GSM48_CMODE_SPEECH_V1) {
+ send_rtp_twts002(lchan, fn, msg);
+ return;
+ }
+
/* Are we applying an ECU to this uplink, and are we in a state
* (not DTX pause) where we emit ECU output? */
if (lchan->ecu_state && !osmo_ecu_is_dtx_pause(lchan->ecu_state)) {
@@ -2526,10 +2588,14 @@
send_ul_rtp_packet(lchan, fn, msg->data, msg->len);
} else if (lchan->type == GSM_LCHAN_TCH_H &&
lchan->tch_mode == GSM48_CMODE_SPEECH_V1) {
- /* HR codec: TS 101 318 or RFC 5993,
- * will also support TW-TS-002 in the future. */
- send_gsmhr_std_rtp(lchan, &g_time, msg,
- bts->emit_hr_rfc5993);
+ /* HR codec: TW-TS-002 in ThemWi environment,
+ * or TS 101 318 or RFC 5993 in traditional
+ * 3GPP or Osmocom environments. */
+ if (lchan->abis_ip.rtp_extensions & OSMO_RTP_EXT_TWTS002)
+ send_rtp_twts002(lchan, fn, msg);
+ else
+ send_gsmhr_std_rtp(lchan, &g_time, msg,
+ bts->emit_hr_rfc5993);
} else {
/* generic case, no RTP alterations */
send_ul_rtp_packet(lchan, fn, msg->data, msg->len);
To view, visit change 41050. To unsubscribe, or for help writing mail filters, visit settings.