falconia has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-bts/+/38557?usp=email )
Change subject: CSD NT modes: transmit properly aligned RLP frames on DL
......................................................................
CSD NT modes: transmit properly aligned RLP frames on DL
There are two levels of alignment inside clearmode RTP packets
carrying CSData per TS 48.103 section 5.6:
1) Alignment of 2 or 4 V.110 (T) or pseudo-V.110 (NT) frames within
one RTP packet of 160 octets of an imaginary ISDN B channel;
2) For NT modes only, alignment of 4 pseudo-V.110 frames to form
a single 240-bit RLP frame.
Per previous patch, alignment 1 is to be treated as mandatory for
RTP transport inside an Osmocom network. Alignment 2 _could_ be
made mandatory for TCH/F9.6 NT, but the same is not possible for
TCH/[FH]4.8 NT: in the best case of half-alignment, alternating
RTP packets will carry alternating halves of RLP frames.
Implemented solution: allow arbitrary state of alignment 2
(aligned or misaligned) in the incoming RTP stream for all CSD NT
modes, and perform the necessary alignment internally.
This approach is consistent with the world of E1 BTS: a TRAU in
data mode is responsible for alignment 1 (with 20 ms TRAU frames
taking the place of our clearmode RTP packets), but only the BTS can
perform alignment 2, as the TRAU is agnostic to T vs NT distinction.
Related: OS#6579
Change-Id: Idaebfce6da13b23ba265a197502712d83991873e
---
M include/osmo-bts/Makefile.am
A include/osmo-bts/csd_rlp.h
M include/osmo-bts/lchan.h
M src/common/Makefile.am
A src/common/csd_rlp.c
M src/common/l1sap.c
6 files changed, 432 insertions(+), 100 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/57/38557/1
diff --git a/include/osmo-bts/Makefile.am b/include/osmo-bts/Makefile.am
index cbd0fc3..1922f0d 100644
--- a/include/osmo-bts/Makefile.am
+++ b/include/osmo-bts/Makefile.am
@@ -24,6 +24,7 @@
tx_power.h \
control_if.h \
cbch.h \
+ csd_rlp.h \
csd_v110.h \
l1sap.h \
lchan.h \
diff --git a/include/osmo-bts/csd_rlp.h b/include/osmo-bts/csd_rlp.h
new file mode 100644
index 0000000..94fa3d2
--- /dev/null
+++ b/include/osmo-bts/csd_rlp.h
@@ -0,0 +1,36 @@
+/*
+ * Declarations for functions in csd_rlp.c: alignment of downlink RLP frames
+ * and RLP GSMTAP mechanism for CSD NT modes.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <osmocom/core/bits.h>
+#include <osmocom/gsm/l1sap.h>
+#include <osmo-bts/lchan.h>
+
+extern const uint8_t csd_tchf48_nt_e2_map[26];
+
+/* Per TS 48.020 section 15.1, the cadence of E2+E3 bits in a properly
+ * aligned sequence of pseudo-V.110 frames forming a single RLP frame
+ * is 00-01-10-11. The following constant captures this bit sequence
+ * in hex, for comparison against align_bits output from
+ * csd_v110_rtp_decode() or against rlpdl_align_bits accumulator
+ * in CSD NT lchan state.
+ */
+#define NTCSD_ALIGNED_EBITS 0x1B
+
+void ntcsd_dl_reset(struct gsm_lchan *lchan);
+void ntcsd_dl_input_48(struct gsm_lchan *lchan, const ubit_t *data_bits,
+ uint8_t align_bits);
+void ntcsd_dl_input_96(struct gsm_lchan *lchan, const ubit_t *data_bits,
+ uint8_t align_bits);
+bool ntcsd_dl_output(struct gsm_lchan *lchan, ubit_t *rlp_frame_out);
+
+void gsmtap_csd_rlp_process(struct gsm_lchan *lchan, bool is_uplink,
+ const struct ph_tch_param *tch_ind,
+ const ubit_t *data, unsigned int data_len);
+void gsmtap_csd_rlp_dl(struct gsm_lchan *lchan, uint32_t fn,
+ const ubit_t *data, unsigned int data_len);
diff --git a/include/osmo-bts/lchan.h b/include/osmo-bts/lchan.h
index df2f4fa..5c34015 100644
--- a/include/osmo-bts/lchan.h
+++ b/include/osmo-bts/lchan.h
@@ -4,6 +4,7 @@
#include <stdint.h>
#include <netinet/in.h>
+#include <osmocom/core/bits.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/logging.h>
@@ -295,9 +296,14 @@
uint8_t last_cmr;
uint32_t last_fn;
struct {
- /* buffers to re-combine RLP frame from multiple Um
blocks */
+ /* RLP GSMTAP mechanism */
uint8_t rlp_buf_ul[576/8]; /* maximum size of RLP frame
*/
uint8_t rlp_buf_dl[576/8]; /* maximum size of RLP frame
*/
+ /* alignment of RLP frames in DL for NT modes */
+ ubit_t rlpdl_data_bits[60 * 7];
+ uint16_t rlpdl_align_bits;
+ uint8_t rlpdl_fill_level;
+ ubit_t tchf48_nt_2ndhalf[120];
} csd;
} tch;
diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index d13415d..1a62e8e 100644
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -51,6 +51,7 @@
bts_ctrl_commands.c \
bts_ctrl_lookup.c \
bts_shutdown_fsm.c \
+ csd_rlp.c \
csd_v110.c \
l1sap.c \
cbch.c \
diff --git a/src/common/csd_rlp.c b/src/common/csd_rlp.c
new file mode 100644
index 0000000..349094c
--- /dev/null
+++ b/src/common/csd_rlp.c
@@ -0,0 +1,228 @@
+/* This module has been split from l1sap.c; original header comments preserved:
+ *
+ * (C) 2011 by Harald Welte <[email protected]>
+ * (C) 2013 by Andreas Eversberg <[email protected]>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/gsm/l1sap.h>
+#include <osmocom/gsm/gsm_utils.h>
+#include <osmocom/gsm/rsl.h>
+#include <osmocom/gsm/rlp.h>
+#include <osmocom/gsm/rtp_extensions.h>
+#include <osmocom/core/gsmtap.h>
+#include <osmocom/core/gsmtap_util.h>
+#include <osmocom/core/utils.h>
+
+#include <osmo-bts/logging.h>
+#include <osmo-bts/gsm_data.h>
+#include <osmo-bts/lchan.h>
+#include <osmo-bts/bts.h>
+#include <osmo-bts/csd_rlp.h>
+
+/* In the case of TCH/F4.8 NT, each 240-bit RLP frame is split between
+ * two channel-coding blocks of 120 bits each. We need to know which
+ * frame numbers correspond to which half: in the UL-to-RTP path we have
+ * to set bit E2 based on the TDMA frame number at which we received the
+ * block in question, and in the DL direction we have to transmit the
+ * right half at the right time.
+ *
+ * See GSM 05.03 section 3.4.1 and the mapping tables of GSM 05.02;
+ * having "e2_map" in the array name shall serve as a mnemonic as to
+ * the sense of this array: 0 means 1st half and 1 means 2nd half,
+ * exactly as the value of bit E2 per TS 48.020 section 15.1.
+ */
+const uint8_t csd_tchf48_nt_e2_map[26] = {
+ [4] = 1, /* B1 position */
+ [13] = 1, /* B3 position */
+ [21] = 1, /* B5 position */
+};
+
+/* This function resets (clears) the state of the DL alignment buffer.
+ * It needs to be called when we encounter a gap (packet loss, invalid
+ * packets, etc) in our RTP input stream. */
+void ntcsd_dl_reset(struct gsm_lchan *lchan)
+{
+ lchan->tch.csd.rlpdl_fill_level = 0;
+}
+
+/* This function is to be called with the decoded content of a single
+ * incoming RTP packet (data and alignment bits) for TCH/[FH]4.8 NT. */
+void ntcsd_dl_input_48(struct gsm_lchan *lchan, const ubit_t *data_bits,
+ uint8_t align_bits)
+{
+ memmove(lchan->tch.csd.rlpdl_data_bits,
+ lchan->tch.csd.rlpdl_data_bits + 60 * 2, 60 * 5);
+ memcpy(lchan->tch.csd.rlpdl_data_bits + 60 * 5, data_bits, 60 * 2);
+ lchan->tch.csd.rlpdl_align_bits <<= 4;
+ lchan->tch.csd.rlpdl_align_bits |= (align_bits & 0xF);
+ lchan->tch.csd.rlpdl_fill_level += 2;
+ if (lchan->tch.csd.rlpdl_fill_level > 7)
+ lchan->tch.csd.rlpdl_fill_level = 7;
+}
+
+/* This function is to be called with the decoded content of a single
+ * incoming RTP packet (data and alignment bits) for TCH/F9.6 NT. */
+void ntcsd_dl_input_96(struct gsm_lchan *lchan, const ubit_t *data_bits,
+ uint8_t align_bits)
+{
+ memmove(lchan->tch.csd.rlpdl_data_bits,
+ lchan->tch.csd.rlpdl_data_bits + 60 * 4, 60 * 3);
+ memcpy(lchan->tch.csd.rlpdl_data_bits + 60 * 3, data_bits, 60 * 4);
+ lchan->tch.csd.rlpdl_align_bits <<= 8;
+ lchan->tch.csd.rlpdl_align_bits |= (align_bits & 0xFF);
+ lchan->tch.csd.rlpdl_fill_level += 4;
+ if (lchan->tch.csd.rlpdl_fill_level > 7)
+ lchan->tch.csd.rlpdl_fill_level = 7;
+}
+
+/* This function is to be called to obtain a complete RLP frame for
+ * downlink transmission. It will provide either a properly aligned
+ * frame (return value true) or a filler (return value false). */
+bool ntcsd_dl_output(struct gsm_lchan *lchan, ubit_t *rlp_frame_out)
+{
+ if (lchan->tch.csd.rlpdl_fill_level < 4)
+ goto no_frame_out;
+ if (((lchan->tch.csd.rlpdl_align_bits >> 0) & 0xFF) ==
NTCSD_ALIGNED_EBITS) {
+ memcpy(rlp_frame_out, lchan->tch.csd.rlpdl_data_bits + 60 * 3,
+ 60 * 4);
+ return true;
+ }
+ if (lchan->tch.csd.rlpdl_fill_level < 5)
+ goto no_frame_out;
+ if (((lchan->tch.csd.rlpdl_align_bits >> 2) & 0xFF) ==
NTCSD_ALIGNED_EBITS) {
+ memcpy(rlp_frame_out, lchan->tch.csd.rlpdl_data_bits + 60 * 2,
+ 60 * 4);
+ return true;
+ }
+ if (lchan->tch.csd.rlpdl_fill_level < 6)
+ goto no_frame_out;
+ if (((lchan->tch.csd.rlpdl_align_bits >> 4) & 0xFF) ==
NTCSD_ALIGNED_EBITS) {
+ memcpy(rlp_frame_out, lchan->tch.csd.rlpdl_data_bits + 60 * 1,
+ 60 * 4);
+ return true;
+ }
+ if (lchan->tch.csd.rlpdl_fill_level < 7)
+ goto no_frame_out;
+ if (((lchan->tch.csd.rlpdl_align_bits >> 6) & 0xFF) ==
NTCSD_ALIGNED_EBITS) {
+ memcpy(rlp_frame_out, lchan->tch.csd.rlpdl_data_bits, 60 * 4);
+ return true;
+ }
+no_frame_out:
+ /* TS 44.021 section 12.1 says that a missing/unavailable 240-bit
+ * RLP frame is to be filled with 0 bits, unlike ones-fill
+ * used everywhere else in the world of V.110 and CSD. */
+ memset(rlp_frame_out, 0, 60 * 4);
+ return false;
+}
+
+/* process one MAC block of unpacked bits of a non-transparent CSD channel */
+void gsmtap_csd_rlp_process(struct gsm_lchan *lchan, bool is_uplink,
+ const struct ph_tch_param *tch_ind,
+ const ubit_t *data, unsigned int data_len)
+{
+ struct gsm_bts_trx *trx = lchan->ts->trx;
+ struct gsmtap_inst *inst = trx->bts->gsmtap.inst;
+ pbit_t *rlp_buf;
+ uint16_t arfcn;
+ int byte_len;
+
+ if (!inst || !trx->bts->gsmtap.rlp)
+ return;
+
+ if (lchan->csd_mode != LCHAN_CSD_M_NT)
+ return;
+
+ if (is_uplink)
+ rlp_buf = lchan->tch.csd.rlp_buf_ul;
+ else
+ rlp_buf = lchan->tch.csd.rlp_buf_dl;
+
+ /* TCH/F 9.6: 4x60bit block => 240bit RLP frame
+ * TCH/F 4.8: 2x 2x60bit blocks starting at B0/B2/B4 => 240bit RLP frame
+ * TCH/H 4.8: 4x60bit block => 240bit RLP frame
+ * TCH/F 2.4: 2x36bit blocks => transparent only
+ * TCH/H 2.4: 4x36bit blocks => transparent only
+ * TCH/F 14.4: 2x 290 bit block (starting with M1=0) => 576-bit RLP
frame
+ */
+
+ if (lchan->type == GSM_LCHAN_TCH_F &&
+ lchan->tch_mode == GSM48_CMODE_DATA_6k0 && is_uplink) {
+ /* In this mode we have 120-bit MAC blocks; two of them need
+ * to be concatenated to render a 240-bit RLP frame. The first
+ * block is present in B0/B2/B4, and we have to use FN to
+ * detect this position.
+ * This code path is only for UL: in the case of DL,
+ * alignment logic elsewhere in the code will present us
+ * with a fully assembled RLP frame. */
+ OSMO_ASSERT(data_len == 120);
+ if (csd_tchf48_nt_e2_map[tch_ind->fn % 26] == 0) {
+ osmo_ubit2pbit_ext(rlp_buf, 0, data, 0, data_len, 1);
+ return;
+ }
+ osmo_ubit2pbit_ext(rlp_buf, 120, data, 0, data_len, 1);
+ byte_len = 240/8;
+ } else if (lchan->type == GSM_LCHAN_TCH_F && lchan->tch_mode ==
GSM48_CMODE_DATA_14k5) {
+ /* in this mode we have 290bit MAC blocks containing M1, M2 and
288 data bits;
+ * two of them need to be concatenated to render a
+ * 576-bit RLP frame. The start of a RLP frame is
+ * denoted by a block with M1-bit set to 0. */
+ OSMO_ASSERT(data_len == 290);
+ ubit_t m1 = data[0];
+ if (m1 == 0) {
+ osmo_ubit2pbit_ext(rlp_buf, 0, data, 2, data_len, 1);
+ return;
+ }
+ osmo_ubit2pbit_ext(rlp_buf, 288, data, 2, data_len, 1);
+ byte_len = 576/8;
+ } else {
+ byte_len = osmo_ubit2pbit_ext(rlp_buf, 0, data, 0, data_len, 1);
+ }
+
+ if (trx->bts->gsmtap.rlp_skip_null) {
+ struct osmo_rlp_frame_decoded rlpf;
+ int rc = osmo_rlp_decode(&rlpf, 0, rlp_buf, byte_len);
+ if (rc == 0 && rlpf.ftype == OSMO_RLP_FT_U && rlpf.u_ftype ==
OSMO_RLP_U_FT_NULL)
+ return;
+ }
+
+ arfcn = trx->arfcn;
+ if (is_uplink)
+ arfcn |= GSMTAP_ARFCN_F_UPLINK;
+
+ gsmtap_send_ex(inst, GSMTAP_TYPE_GSM_RLP, arfcn, lchan->ts->nr,
+ lchan->type == GSM_LCHAN_TCH_H ? GSMTAP_CHANNEL_VOICE_H
: GSMTAP_CHANNEL_VOICE_F,
+ lchan->nr, tch_ind->fn, tch_ind->rssi, 0, rlp_buf,
byte_len);
+
+}
+
+/* wrapper for downlink path */
+void gsmtap_csd_rlp_dl(struct gsm_lchan *lchan, uint32_t fn,
+ const ubit_t *data, unsigned int data_len)
+{
+ /* 'fake' tch_ind containing all-zero so gsmtap code can be shared
+ * between UL and DL */
+ const struct ph_tch_param fake_tch_ind = { .fn = fn };
+ gsmtap_csd_rlp_process(lchan, false, &fake_tch_ind, data, data_len);
+}
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index 793b7a8..6c4eefe 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -60,6 +60,7 @@
#include <osmo-bts/pcuif_proto.h>
#include <osmo-bts/cbch.h>
#include <osmo-bts/asci.h>
+#include <osmo-bts/csd_rlp.h>
#include <osmo-bts/csd_v110.h>
/* determine the CCCH block number based on the frame number */
@@ -1516,6 +1517,7 @@
struct osmo_phsap_prim *resp_l1sap, empty_l1sap;
uint8_t *phy_data;
struct gsm_time g_time;
+ bool good_rlp;
int i;
/* The generic scheduler still sends us TCH-RTS.ind every 20 ms,
@@ -1545,16 +1547,36 @@
&lchan->dl_tch_queue_len);
}
+ if (lchan->csd_mode == LCHAN_CSD_M_NT) {
+ for (i = 0; i < 2; i++) {
+ if (input_msg[i]) {
+ ntcsd_dl_input_48(lchan, input_msg[i]->data,
+ rtpmsg_csd_align_bits(input_msg[i]));
+ } else {
+ ntcsd_dl_reset(lchan);
+ }
+ }
+ }
+
phy_msg = l1sap_msgb_alloc(bits_per_20ms * 2);
if (phy_msg) {
resp_l1sap = msgb_l1sap_prim(phy_msg);
phy_msg->l2h = phy_msg->tail;
- for (i = 0; i < 2; i++) {
- phy_data = msgb_put(phy_msg, bits_per_20ms);
- if (input_msg[i])
- memcpy(phy_data, input_msg[i]->data,
bits_per_20ms);
- else
- memset(phy_data, 0x01, bits_per_20ms);
+ if (lchan->csd_mode == LCHAN_CSD_M_NT) {
+ phy_data = msgb_put(phy_msg, 240); /* RLP frame */
+ good_rlp = ntcsd_dl_output(lchan, phy_data);
+ if (good_rlp)
+ gsmtap_csd_rlp_dl(lchan, fn, phy_data, 240);
+ } else {
+ for (i = 0; i < 2; i++) {
+ phy_data = msgb_put(phy_msg, bits_per_20ms);
+ if (input_msg[i]) {
+ memcpy(phy_data, input_msg[i]->data,
+ bits_per_20ms);
+ } else {
+ memset(phy_data, 0x01, bits_per_20ms);
+ }
+ }
}
} else {
resp_l1sap = &empty_l1sap;
@@ -1579,6 +1601,111 @@
return 0;
}
+/* The case of TCH/F4.8 NT also requires special processing that is
+ * somewhat similar to half-rate CSD. We have to produce an RLP frame
+ * for DL every 40 ms, thus it makes the most sense for us to poll
+ * the Rx jitter buffer every 40 ms just like with CSD-HR. However,
+ * we need to send TCH.req to the PHY every 20 ms, sending either
+ * the first half or the second half of the RLP frame we put together
+ * every 40 ms. */
+static int tch_rts_ind_tchf48_nt(struct gsm_bts_trx *trx,
+ struct gsm_lchan *lchan,
+ struct ph_tch_param *rts_ind)
+{
+ uint8_t chan_nr = rts_ind->chan_nr;
+ uint32_t fn = rts_ind->fn;
+ struct msgb *input_msg, *phy_msg;
+ struct osmo_phsap_prim *resp_l1sap, empty_l1sap;
+ ubit_t rlp_frame[240];
+ bool good_rlp;
+ struct gsm_time g_time;
+ int i;
+
+ gsm_fn2gsmtime(&g_time, fn);
+
+ /* Input processing happens every 40 ms */
+ if (csd_tchf48_nt_e2_map[fn % 26] == 0) {
+ for (i = 0; i < 2; i++) {
+ if (!lchan->loopback && lchan->abis_ip.rtp_socket) {
+ osmo_rtp_socket_poll(lchan->abis_ip.rtp_socket);
+ lchan->abis_ip.rtp_socket->rx_user_ts +=
GSM_RTP_DURATION;
+ }
+ input_msg = msgb_dequeue_count(&lchan->dl_tch_queue,
+
&lchan->dl_tch_queue_len);
+ if (input_msg) {
+ ntcsd_dl_input_48(lchan, input_msg->data,
+ rtpmsg_csd_align_bits(input_msg));
+ msgb_free(input_msg);
+ } else {
+ ntcsd_dl_reset(lchan);
+ }
+ }
+ good_rlp = ntcsd_dl_output(lchan, rlp_frame);
+ if (good_rlp)
+ gsmtap_csd_rlp_dl(lchan, fn, rlp_frame, 240);
+ memcpy(lchan->tch.csd.tchf48_nt_2ndhalf, rlp_frame+120, 120);
+ }
+
+ /* back to every 20 ms code path */
+ phy_msg = l1sap_msgb_alloc(120); /* half of RLP frame */
+ if (phy_msg) {
+ resp_l1sap = msgb_l1sap_prim(phy_msg);
+ phy_msg->l2h = msgb_put(phy_msg, 120);
+ if (csd_tchf48_nt_e2_map[fn % 26] == 0)
+ memcpy(phy_msg->l2h, rlp_frame, 120);
+ else
+ memcpy(phy_msg->l2h, lchan->tch.csd.tchf48_nt_2ndhalf,
120);
+ } else {
+ resp_l1sap = &empty_l1sap;
+ }
+
+ memset(resp_l1sap, 0, sizeof(*resp_l1sap));
+ osmo_prim_init(&resp_l1sap->oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_REQUEST,
+ phy_msg);
+ resp_l1sap->u.tch.chan_nr = chan_nr;
+ resp_l1sap->u.tch.fn = fn;
+ resp_l1sap->u.tch.marker = 0; /* M bit is undefined for clearmode */
+
+ LOGPLCGT(lchan, &g_time, DL1P, LOGL_DEBUG, "Tx TCH.req\n");
+
+ l1sap_down(trx, resp_l1sap);
+
+ return 0;
+}
+
+/* For TCH/F9.6 NT we need much less special processing than for TCH/F4.8 NT
+ * or for CSD-HR, but we still need to handle the possibility of misaligned
+ * RTP input, i.e., pseudo-V.110 frames aligned in the packet, but not
+ * forming proper RLP frame alignment via E2 & E3 bits. */
+static void tchf96_nt_dl_alignment(struct gsm_lchan *lchan, struct msgb *msg,
+ uint32_t fn)
+{
+ bool good_rlp;
+
+ if (!msg) {
+ ntcsd_dl_reset(lchan);
+ /* FIXME: do we really need to generate a PHY packet filled
+ * with 0 bits to satisfy TS 44.021 section 12.1, or can we
+ * get by with letting the PHY fill in ones like it does
+ * for all other CSD modes? */
+ return;
+ }
+ /* Fast path: handle the good case of already proper alignment */
+ if ((rtpmsg_csd_align_bits(msg) & 0xFF) == NTCSD_ALIGNED_EBITS) {
+ /* clear the buffer in case we have to do misaligned packets
+ * later, but otherwise let it go! */
+ ntcsd_dl_reset(lchan);
+ gsmtap_csd_rlp_dl(lchan, fn, msgb_l2(msg), msgb_l2len(msg));
+ return;
+ }
+ /* Slow path: realign like in other NT modes */
+ OSMO_ASSERT(msgb_l2len(msg) == 240);
+ ntcsd_dl_input_96(lchan, msgb_l2(msg), rtpmsg_csd_align_bits(msg));
+ good_rlp = ntcsd_dl_output(lchan, msgb_l2(msg));
+ if (good_rlp)
+ gsmtap_csd_rlp_dl(lchan, fn, msgb_l2(msg), msgb_l2len(msg));
+}
+
/* TCH-RTS-IND prim received from bts model */
static int l1sap_tch_rts_ind(struct gsm_bts_trx *trx,
struct osmo_phsap_prim *l1sap, struct ph_tch_param *rts_ind)
@@ -1604,8 +1731,14 @@
LOGPLCGT(lchan, &g_time, DL1P, LOGL_DEBUG, "Rx TCH-RTS.ind\n");
}
- if (lchan->rsl_cmode == RSL_CMOD_SPD_DATA && lchan->type ==
GSM_LCHAN_TCH_H)
+ /* CSD-HR requires special processing */
+ if (lchan->rsl_cmode == RSL_CMOD_SPD_DATA &&
+ lchan->type == GSM_LCHAN_TCH_H)
return tch_rts_ind_csd_hr(trx, lchan, rts_ind);
+ /* so does TCH/F4.8 NT mode */
+ if (lchan->tch_mode == GSM48_CMODE_DATA_6k0 &&
+ lchan->csd_mode == LCHAN_CSD_M_NT)
+ return tch_rts_ind_tchf48_nt(trx, lchan, rts_ind);
if (!lchan->loopback && lchan->abis_ip.rtp_socket) {
osmo_rtp_socket_poll(lchan->abis_ip.rtp_socket);
@@ -1653,6 +1786,24 @@
&resp_l1sap, &empty_l1sap);
}
+ /* minimal extra handling for the remaining CSD NT modes */
+ if (lchan->rsl_cmode == RSL_CMOD_SPD_DATA &&
+ lchan->csd_mode == LCHAN_CSD_M_NT) {
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_DATA_12k0:
+ tchf96_nt_dl_alignment(lchan, resp_msg, fn);
+ break;
+ case GSM48_CMODE_DATA_14k5:
+ gsmtap_csd_rlp_dl(lchan, fn, msgb_l2(resp_msg),
+ msgb_l2len(resp_msg));
+ break;
+ default:
+ LOGPLCGT(lchan, &g_time, DL1P, LOGL_ERROR,
+ "Invalid TCH mode in TCH-RTS.ind under CSD
NT\n");
+ break;
+ }
+ }
+
memset(resp_l1sap, 0, sizeof(*resp_l1sap));
osmo_prim_init(&resp_l1sap->oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_REQUEST,
resp_msg);
@@ -1942,84 +2093,6 @@
return 1;
}
-/* process one MAC block of unpacked bits of a non-transparent CSD channel */
-static void gsmtap_csd_rlp_process(struct gsm_lchan *lchan, bool is_uplink,
- const struct ph_tch_param *tch_ind,
- const uint8_t *data, unsigned int data_len)
-{
- struct gsm_bts_trx *trx = lchan->ts->trx;
- struct gsmtap_inst *inst = trx->bts->gsmtap.inst;
- pbit_t *rlp_buf;
- uint16_t arfcn;
- int byte_len;
-
- if (!inst || !trx->bts->gsmtap.rlp)
- return;
-
- if (lchan->csd_mode != LCHAN_CSD_M_NT)
- return;
-
- if (is_uplink)
- rlp_buf = lchan->tch.csd.rlp_buf_ul;
- else
- rlp_buf = lchan->tch.csd.rlp_buf_dl;
-
- /* TCH/F 9.6: 4x60bit block => 240bit RLP frame
- * TCH/F 4.8: 2x 2x60bit blocks starting at B0/B2/B4 => 240bit RLP frame
- * TCH/H 4.8: 4x60bit block => 240bit RLP frame
- * TCH/F 2.4: 2x36bit blocks => transparent only
- * TCH/H 2.4: 4x36bit blocks => transparent only
- * TCH/F 14.4: 2x 290 bit block (starting with M1=0) => 576-bit RLP
frame
- */
-
- if (lchan->type == GSM_LCHAN_TCH_F && lchan->tch_mode ==
GSM48_CMODE_DATA_6k0) {
- /* in this mode we have 120bit MAC blocks; two of them need to
be concatenated
- * to render a 240-bit RLP frame. The fist block is present in
B0/B2/B4.
- * The E7 bit is used to indicate the Frame MF0a */
- OSMO_ASSERT(data_len == 120);
- ubit_t e7 = data[4*7+3];
- if (e7 == 0) {
- osmo_ubit2pbit_ext(rlp_buf, 0, data, 0, data_len, 1);
- return;
- } else {
- osmo_ubit2pbit_ext(rlp_buf, 120, data, 0, data_len, 1);
- byte_len = 240/8;
- }
- } else if (lchan->type == GSM_LCHAN_TCH_F && lchan->tch_mode ==
GSM48_CMODE_DATA_14k5) {
- /* in this mode we have 290bit MAC blocks containing M1, M2 and
288 data bits;
- * two of them need to be concatenated to render a
- * 576-bit RLP frame. The start of a RLP frame is
- * denoted by a block with M1-bit set to 0. */
- OSMO_ASSERT(data_len == 290);
- ubit_t m1 = data[0];
- if (m1 == 0) {
- osmo_ubit2pbit_ext(rlp_buf, 0, data, 2, data_len, 1);
- return;
- } else {
- osmo_ubit2pbit_ext(rlp_buf, 288, data, 2, data_len, 1);
- byte_len = 576/8;
- }
- } else {
- byte_len = osmo_ubit2pbit_ext(rlp_buf, 0, data, 0, data_len, 1);
- }
-
- if (trx->bts->gsmtap.rlp_skip_null) {
- struct osmo_rlp_frame_decoded rlpf;
- int rc = osmo_rlp_decode(&rlpf, 0, rlp_buf, byte_len);
- if (rc == 0 && rlpf.ftype == OSMO_RLP_FT_U && rlpf.u_ftype ==
OSMO_RLP_U_FT_NULL)
- return;
- }
-
- arfcn = trx->arfcn;
- if (is_uplink)
- arfcn |= GSMTAP_ARFCN_F_UPLINK;
-
- gsmtap_send_ex(inst, GSMTAP_TYPE_GSM_RLP, arfcn, lchan->ts->nr,
- lchan->type == GSM_LCHAN_TCH_H ? GSMTAP_CHANNEL_VOICE_H
: GSMTAP_CHANNEL_VOICE_F,
- lchan->nr, tch_ind->fn, tch_ind->rssi, 0, rlp_buf,
byte_len);
-
-}
-
/* a helper function for the logic in l1sap_tch_ind() */
static void send_ul_rtp_packet(struct gsm_lchan *lchan, uint32_t fn,
const uint8_t *rtp_pl, uint16_t rtp_pl_len)
@@ -2060,20 +2133,11 @@
lchan->rtp_tx_marker = false;
}
-/* In the case of TCH/F4.8 NT, we have to set bit E2 based on the TDMA
- * frame number at which we received the block in question. See
- * GSM 05.03 section 3.4.1 and the mapping tables of GSM 05.02. */
-static const uint8_t tchf48_nt_e2_map[26] = {
- [4] = 1, /* B1 position */
- [13] = 1, /* B3 position */
- [21] = 1, /* B5 position */
-};
-
static void handle_tch_ind_csd_fr(struct gsm_lchan *lchan, const struct
ph_tch_param *tch_ind,
const uint8_t *data, uint16_t data_len)
{
uint8_t rtp_pl[RFC4040_RTP_PLEN];
- uint8_t tchf48_half = tchf48_nt_e2_map[tch_ind->fn % 26];
+ uint8_t tchf48_half = csd_tchf48_nt_e2_map[tch_ind->fn % 26];
int rc;
gsmtap_csd_rlp_process(lchan, true, tch_ind, data, data_len);
@@ -2645,10 +2709,6 @@
int rc = csd_v110_rtp_decode(lchan, msg->tail, &csd_align_bits,
rtp_pl, rtp_pl_len);
if (rc > 0) {
- /* 'fake' tch_ind containing all-zero so gsmtap code
can be shared
- * between UL and DL */
- static const struct ph_tch_param fake_tch_ind = {};
- gsmtap_csd_rlp_process(lchan, false, &fake_tch_ind,
msg->tail, rc);
msgb_put(msg, rc);
} else {
rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_DROP_V110_DEC);
--
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Gerrit-MessageType: newchange
Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: Idaebfce6da13b23ba265a197502712d83991873e
Gerrit-Change-Number: 38557
Gerrit-PatchSet: 1
Gerrit-Owner: falconia <[email protected]>
