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laforge gerrit-no-reply at lists.osmocom.orglaforge has submitted this change. ( https://gerrit.osmocom.org/c/osmo-trx/+/18005 )
Change subject: PRBS tool sending PRBS sequence to TRX
......................................................................
PRBS tool sending PRBS sequence to TRX
Change-Id: I2300f909bbfda10a7053320edfd1deaea763759a
---
M Makefile.am
M configure.ac
A utils/Makefile.am
A utils/prbs-tool.c
4 files changed, 327 insertions(+), 1 deletion(-)
Approvals:
pespin: Looks good to me, but someone else must approve
laforge: Looks good to me, approved
Jenkins Builder: Verified
diff --git a/Makefile.am b/Makefile.am
index 8b55e79..9462fa8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -33,7 +33,8 @@
GSM \
Transceiver52M \
contrib \
- tests
+ tests \
+ utils
EXTRA_DIST = \
LEGAL \
diff --git a/configure.ac b/configure.ac
index b7b0d00..d0cfe44 100644
--- a/configure.ac
+++ b/configure.ac
@@ -92,6 +92,7 @@
PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 1.3.0)
PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 1.3.0)
PKG_CHECK_MODULES(LIBOSMOCTRL, libosmoctrl >= 1.3.0)
+PKG_CHECK_MODULES(LIBOSMOCODING, libosmocoding >= 1.3.0)
AC_ARG_ENABLE(sanitize,
[AS_HELP_STRING(
@@ -327,6 +328,7 @@
tests/Makefile \
tests/CommonLibs/Makefile \
tests/Transceiver52M/Makefile \
+ utils/Makefile \
doc/Makefile \
doc/examples/Makefile \
contrib/Makefile \
diff --git a/utils/Makefile.am b/utils/Makefile.am
new file mode 100644
index 0000000..0b8bda0
--- /dev/null
+++ b/utils/Makefile.am
@@ -0,0 +1,7 @@
+AM_CPPFLAGS = $(LIBOSMOCODING_CFLAGS)
+AM_CFLAGS = -Wall
+
+noinst_PROGRAMS = osmo-prbs-tool
+
+osmo_prbs_tool_SOURCES = prbs-tool.c
+osmo_prbs_tool_LDADD = $(LIBOSMOCODING_LIBS)
diff --git a/utils/prbs-tool.c b/utils/prbs-tool.c
new file mode 100644
index 0000000..de68f0b
--- /dev/null
+++ b/utils/prbs-tool.c
@@ -0,0 +1,316 @@
+/* Dummy TRX for sening PRBS test sequences into osmo-bts-trx to test
+ * the decoder/receiver processing in osmo-bts-trx as well as any
+ * additional PRBS testing code.
+ *
+ * The purpose of this program is to use it as a mock dummy MS-side
+ * transmitter of GSM bursts that contain encoded PRBS sequences,
+ * similar to what one would normally do with an arbitrary
+ * function/waveform generator or BERT tester in hardware.
+ *
+ * (C) 2017 by Harald Welte <laforge at gnumonks.org>
+ * All Rights Reserved
+ *
+ * Licensed under terms of the GNU Generral Public License, Version 2,
+ * or (at your option) any later version.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include <netinet/in.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/prbs.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/gsm/gsm_utils.h>
+#include <osmocom/coding/gsm0503_coding.h>
+
+/***********************************************************************
+ * GSM Constants
+ ***********************************************************************/
+
+#define GSM_FR_BYTES 33
+#define GSM_BURST_BITS 116
+#define GSM_4BURST_BITS (GSM_BURST_BITS*4)
+#define GSM_BURST_LEN 148
+
+
+/***********************************************************************
+ * TRX Interface / Protocol
+ ***********************************************************************/
+
+#define TRX_BASE_PORT 5700
+/* DATA port on the TRX side */
+#define TRX_PORT_CTRL_TRX(C) (TRX_BASE_PORT+(2*(C))+1)
+#define TRX_PORT_DATA_TRX(C) (TRX_BASE_PORT+(2*(C))+2)
+#define TRX_PORT_CTRL_BTS(C) (TRX_PORT_CTRL_TRX(C)+100)
+#define TRX_PORT_DATA_BTS(C) (TRX_PORT_DATA_TRX(C)+100)
+
+struct trx_ul_msg {
+ uint8_t ts;
+ uint32_t fn;
+ uint8_t rssi;
+ uint16_t t_offs;
+ sbit_t bits[148];
+} __attribute__((packed));
+
+struct trx_dl_msg {
+ uint8_t ts;
+ uint32_t fn;
+ uint8_t att_db;
+ ubit_t bits[148];
+} __attribute__((packed));
+
+
+/***********************************************************************
+ * Helper Functions
+ ***********************************************************************/
+
+static int ubits2trxbits(uint8_t *sbits, const ubit_t *ubits, unsigned int count)
+{
+ unsigned int i;
+
+ for (i = 0; i < count; i++) {
+ if ((*ubits++) & 1) {
+ *sbits++ = 255;
+ } else {
+ *sbits++ = 0;
+ }
+ }
+
+ return count;
+}
+
+static int __attribute__((__unused__)) dec(const ubit_t *bursts_u)
+{
+ sbit_t bursts_s[GSM_4BURST_BITS*2];
+ uint8_t dec_tch_data[GSM_FR_BYTES];
+ int n_errors, n_bits_total;
+ int rc;
+
+ /* convert from u_bit (tx) to s_bit (rx) */
+ osmo_ubit2sbit(bursts_s, bursts_u, sizeof(bursts_s));
+
+ rc = gsm0503_tch_fr_decode(dec_tch_data, bursts_s, 1, 0, &n_errors, &n_bits_total);
+ printf("rc=%d, n_errors=%d, n_bits_total=%d: %s\n", rc, n_errors, n_bits_total,
+ osmo_hexdump(dec_tch_data, sizeof(dec_tch_data)));
+
+ return rc;
+}
+
+/*! \brief Training Sequences (TS 05.02 Chapter 5.2.3) */
+static const ubit_t _sched_tsc[8][26] = {
+ { 0,0,1,0,0,1,0,1,1,1,0,0,0,0,1,0,0,0,1,0,0,1,0,1,1,1, },
+ { 0,0,1,0,1,1,0,1,1,1,0,1,1,1,1,0,0,0,1,0,1,1,0,1,1,1, },
+ { 0,1,0,0,0,0,1,1,1,0,1,1,1,0,1,0,0,1,0,0,0,0,1,1,1,0, },
+ { 0,1,0,0,0,1,1,1,1,0,1,1,0,1,0,0,0,1,0,0,0,1,1,1,1,0, },
+ { 0,0,0,1,1,0,1,0,1,1,1,0,0,1,0,0,0,0,0,1,1,0,1,0,1,1, },
+ { 0,1,0,0,1,1,1,0,1,0,1,1,0,0,0,0,0,1,0,0,1,1,1,0,1,0, },
+ { 1,0,1,0,0,1,1,1,1,1,0,1,1,0,0,0,1,0,1,0,0,1,1,1,1,1, },
+ { 1,1,1,0,1,1,1,1,0,0,0,1,0,0,1,0,1,1,1,0,1,1,1,1,0,0, },
+};
+
+/***********************************************************************
+ * state + processing functions
+ ***********************************************************************/
+
+/* state we have to keep for one physical channel */
+struct pchan_data {
+ /* PRBS state */
+ struct osmo_prbs_state st;
+ /* unpacked PRBS bits, generated from PRBS */
+ ubit_t prbs_u[4+260];
+ /* packed frame (to be sent) */
+ uint8_t tch_data[GSM_FR_BYTES];
+ /* burst bits (ubit) to be transmitted */
+ ubit_t bursts[GSM_4BURST_BITS*2]; /* 116 * 8 */
+ /* burst bits (sbit) 'as if received' */
+ sbit_t bursts_s[GSM_4BURST_BITS*2];
+ /* next to-be transmitted burst number */
+ unsigned int burst_nr;
+ /* training sequence code */
+ unsigned int tsc;
+};
+
+struct ts_data {
+ struct pchan_data pchan[2];
+};
+
+struct trx_data {
+ struct ts_data ts[8];
+};
+
+static struct trx_data g_trx_data;
+
+/* initialize the state for one TRX */
+static void trx_data_init(struct trx_data *trx)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(trx->ts); i++) {
+ struct ts_data *ts = &trx->ts[i];
+ int j;
+ for (j = 0; j < ARRAY_SIZE(ts->pchan); j++) {
+ struct pchan_data *pchan = &ts->pchan[j];
+
+ memset(pchan, 0, sizeof(*pchan));
+ osmo_prbs_state_init(&pchan->st, &osmo_prbs9);
+ pchan->tsc = 7;
+ }
+ }
+}
+
+/*! obtain the next to-be-transmitted burst for the given pchan
+ * \param pchan physical channel on which we operate
+ * \param[in] fn frame number
+ * \param[out] burst_out caller-provided buffer for 148 unpacked output bits
+ * \retruns number of bits stored in \a burst_out */
+static int pchan_get_next_burst(struct pchan_data *pchan, uint32_t fn, ubit_t *burst_out)
+{
+ uint32_t fn26 = fn % 26;
+ int rc;
+
+ if (fn26 == 0 || fn26 == 4 || fn26 == 8 || fn26 == 13 || fn26 == 17 || fn26 == 21)
+ pchan->burst_nr = 0;
+
+ if (fn26 == 12 || fn26 == 25) {
+ memset(burst_out, 0, GSM_BURST_LEN);
+ return GSM_BURST_LEN;
+ }
+
+ if (pchan->burst_nr == 0) {
+ /* generate PRBS output in ubit format, skipping first nibble for 260-264 padding */
+ const uint8_t prefix[] = { 0xd0 };
+ osmo_pbit2ubit(pchan->prbs_u, prefix, 4);
+ rc = osmo_prbs_get_ubits(pchan->prbs_u+4, sizeof(pchan->prbs_u)-4, &pchan->st);
+ OSMO_ASSERT(rc == sizeof(pchan->prbs_u)-4);
+ /* pack to PBIT format */
+ rc = osmo_ubit2pbit(pchan->tch_data, pchan->prbs_u, sizeof(pchan->prbs_u));
+ //memset(pchan->tch_data, 0xff, sizeof(pchan->tch_data));
+
+ printf("%s\n", osmo_hexdump(pchan->tch_data, GSM_FR_BYTES));
+
+ /* shift buffer by 4 bursts for interleaving */
+ memcpy(pchan->bursts, pchan->bursts + GSM_4BURST_BITS, GSM_4BURST_BITS);
+ memset(pchan->bursts + GSM_4BURST_BITS, 0, GSM_4BURST_BITS);
+
+ /* encode block (codec frame) into four bursts */
+ rc = gsm0503_tch_fr_encode(pchan->bursts, pchan->tch_data, GSM_FR_BYTES, 1);
+ OSMO_ASSERT(rc == 0);
+
+ for (int i = 0; i < sizeof(pchan->bursts); i += GSM_BURST_BITS)
+ printf("\t%s\n", osmo_ubit_dump(pchan->bursts + i, GSM_BURST_BITS));
+
+// dec(pchan->bursts);
+ }
+
+ /* for all bursts: format 148 symbols from 116 input bits */
+ ubit_t *burst = pchan->bursts + pchan->burst_nr * GSM_BURST_BITS;
+ printf("TX(%u): %s\n", pchan->burst_nr, osmo_ubit_dump(burst, GSM_BURST_BITS));
+ memset(burst_out, 0, 3); /* guard bits */
+ memcpy(burst_out+3, burst, 58); /* firrst half */
+ memcpy(burst_out+61, _sched_tsc[pchan->tsc], 26); /* midamble */
+ memcpy(burst_out+87, burst+58, 58); /* second half */
+ memset(burst_out+145, 0, 3); /* guard bits */
+
+ /* increment burst number for next call */
+ pchan->burst_nr += 1;
+#if 0
+ if (pchan->burst_nr == 4)
+ pchan->burst_nr = 0;
+#endif
+
+ return GSM_BURST_LEN;
+}
+
+static int pchan_process_ts_fn(struct pchan_data *pchan, uint32_t fn, uint8_t *burst_t)
+{
+ ubit_t burst_u[GSM_BURST_LEN];
+ int rc;
+
+ rc = pchan_get_next_burst(pchan, fn, burst_u);
+ OSMO_ASSERT(rc == sizeof(burst_u));
+
+ /* convert from u_bit (tx) to s_bit (rx) */
+ ubits2trxbits(burst_t, burst_u, GSM_BURST_LEN);
+
+ return GSM_BURST_LEN;
+}
+
+/* read TRX DL data from BTS, write TRX UL data to BTS */
+static int read_and_process(int fd)
+{
+ /* receive (downlink) buffer */
+ uint8_t rx_dl_buf[1024];
+ struct trx_dl_msg *dl_msg = (struct trx_dl_msg *) rx_dl_buf;
+ /* transmit (uplink) buffer */
+ uint8_t tx_ul_buf[1024];
+ struct trx_ul_msg *ul_msg = (struct trx_ul_msg *) tx_ul_buf;
+ /* other variables */
+ struct pchan_data *pchan;
+ uint8_t rc;
+
+ /* do a blocking read on the socket and receive DL from BTS */
+ rc = read(fd, rx_dl_buf, sizeof(rx_dl_buf));
+ if (rc < sizeof(*dl_msg))
+ return rc;
+
+ dl_msg->fn = ntohl(dl_msg->fn);
+
+ if (dl_msg->ts >= ARRAY_SIZE(g_trx_data.ts))
+ return -ENODEV;
+
+ if (dl_msg->ts != 2)
+ return 0;
+
+ printf("FN=%s TS=%u\n", gsm_fn_as_gsmtime_str(dl_msg->fn), dl_msg->ts);
+
+ /* FIXME: second pchan for TCH/H */
+ pchan = &g_trx_data.ts[dl_msg->ts].pchan[0];
+
+ rc = pchan_process_ts_fn(pchan, dl_msg->fn, (uint8_t *) ul_msg->bits);
+ OSMO_ASSERT(rc == sizeof(ul_msg->bits));
+
+ /* copy over timeslot and frame number */
+ ul_msg->fn = htonl(dl_msg->fn);
+ ul_msg->ts = dl_msg->ts;
+
+ /* write uplink message towards BTS */
+ rc = write(fd, tx_ul_buf, sizeof(*ul_msg));
+ if (rc < sizeof(*ul_msg))
+ return -EIO;
+
+ return 0;
+}
+
+static int open_trx_data_sock(unsigned int trx_nr, const char *bts_host)
+{
+ int rc;
+
+ rc = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, TRX_PORT_DATA_TRX(trx_nr),
+ bts_host, TRX_PORT_DATA_BTS(trx_nr),
+ OSMO_SOCK_F_CONNECT | OSMO_SOCK_F_BIND);
+ return rc;
+}
+
+
+int main(int argc, char **argv)
+{
+ int fd;
+
+ trx_data_init(&g_trx_data);
+
+ fd = open_trx_data_sock(0, "127.0.0.1");
+ if (fd < 0)
+ exit(1);
+
+ while (1) {
+ read_and_process(fd);
+ }
+
+ return 0;
+}
--
To view, visit https://gerrit.osmocom.org/c/osmo-trx/+/18005
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Gerrit-Project: osmo-trx
Gerrit-Branch: master
Gerrit-Change-Id: I2300f909bbfda10a7053320edfd1deaea763759a
Gerrit-Change-Number: 18005
Gerrit-PatchSet: 1
Gerrit-Owner: laforge <laforge at osmocom.org>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <laforge at osmocom.org>
Gerrit-Reviewer: pespin <pespin at sysmocom.de>
Gerrit-MessageType: merged
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