trxcon/scheduler: add TCH/H channel support

Change-Id: Ibb2a0850692c5ff86b13b820af10b12085589e67
changes/60/10460/3
Vadim Yanitskiy 5 years ago
parent 1bffe899d9
commit 7d06c78b37
  1. 11
      src/host/trxcon/sched_lchan_desc.c
  2. 319
      src/host/trxcon/sched_lchan_tchh.c
  3. 2
      src/host/trxcon/sched_trx.c
  4. 6
      src/host/trxcon/sched_trx.h

@ -27,10 +27,7 @@
/* TODO: implement */
#define tx_pdtch_fn NULL
#define tx_tchh_fn NULL
#define rx_pdtch_fn NULL
#define rx_tchh_fn NULL
/* Forward declaration of handlers */
int rx_data_fn(struct trx_instance *trx, struct trx_ts *ts,
@ -54,6 +51,14 @@ int rx_tchf_fn(struct trx_instance *trx, struct trx_ts *ts,
int tx_tchf_fn(struct trx_instance *trx, struct trx_ts *ts,
struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid);
int rx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid,
sbit_t *bits, int8_t rssi, int16_t toa256);
int tx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid);
const struct trx_lchan_desc trx_lchan_desc[_TRX_CHAN_MAX] = {
{
TRXC_IDLE, "IDLE",

@ -3,6 +3,7 @@
* TDMA scheduler: handlers for DL / UL bursts on logical channels
*
* (C) 2018 by Vadim Yanitskiy <axilirator@gmail.com>
* (C) 2018 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
@ -23,11 +24,27 @@
*/
#include <errno.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/bits.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/coding/gsm0503_coding.h>
#include <osmocom/codec/codec.h>
#include "l1ctl_proto.h"
#include "scheduler.h"
#include "sched_trx.h"
#include "logging.h"
#include "trx_if.h"
#include "trxcon.h"
#include "l1ctl.h"
static const uint8_t tch_h0_traffic_block_map[3][4] = {
/* B0(0,2,4,6), B1(4,6,8,10), B2(8,10,0,2) */
@ -181,3 +198,305 @@ uint32_t sched_tchh_block_dl_first_fn(enum trx_lchan_type chan,
/* Couldn't calculate the first fn, return the last */
return last_fn;
}
int rx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid,
sbit_t *bits, int8_t rssi, int16_t toa256)
{
const struct trx_lchan_desc *lchan_desc;
int n_errors = -1, n_bits_total, rc;
sbit_t *buffer, *offset;
uint8_t l2[128], *mask;
size_t l2_len;
/* Set up pointers */
lchan_desc = &trx_lchan_desc[lchan->type];
mask = &lchan->rx_burst_mask;
buffer = lchan->rx_bursts;
LOGP(DSCHD, LOGL_DEBUG, "Traffic received on %s: fn=%u ts=%u bid=%u\n",
lchan_desc->name, fn, ts->index, bid);
if (*mask == 0x00) {
/* Align to the first burst */
if (bid > 0)
return 0;
/* Align reception of the first FACCH/H frame */
if (lchan->tch_mode == GSM48_CMODE_SIGN) {
if (!sched_tchh_facch_start(lchan->type, fn, 0))
return 0;
} else { /* or TCH/H traffic frame */
if (!sched_tchh_traffic_start(lchan->type, fn, 0))
return 0;
}
}
/* Update mask */
*mask |= (1 << bid);
/**
* FIXME: properly update measurements
*
* Since TCH/H channel is using block-diagonal interleaving,
* a single burst may carry 57 bits of one encoded frame,
* and 57 bits of another. This should be taken into account.
*/
lchan->meas.rssi_sum += rssi;
lchan->meas.toa256_sum += toa256;
lchan->meas.rssi_num++;
lchan->meas.toa256_num++;
/* Copy burst to the end of buffer of 6 bursts */
offset = buffer + bid * 116 + 464;
memcpy(offset, bits + 3, 58);
memcpy(offset + 58, bits + 87, 58);
/* Wait until the second burst */
if (bid != 1)
return 0;
/* Wait for complete set of bursts */
if (lchan->tch_mode == GSM48_CMODE_SIGN) {
/* FACCH/H is interleaved over 6 bursts */
if ((*mask & 0x3f) != 0x3f)
goto bfi_shift;
} else {
/* Traffic is interleaved over 4 bursts */
if ((*mask & 0x0f) != 0x0f)
goto bfi_shift;
}
/* Skip decoding attempt in case of FACCH/H */
if (lchan->dl_ongoing_facch) {
lchan->dl_ongoing_facch = false;
goto bfi_shift; /* 2/2 BFI */
}
switch (lchan->tch_mode) {
case GSM48_CMODE_SIGN:
case GSM48_CMODE_SPEECH_V1: /* HR */
rc = gsm0503_tch_hr_decode(l2, buffer,
!sched_tchh_facch_end(lchan->type, fn, 0),
&n_errors, &n_bits_total);
break;
case GSM48_CMODE_SPEECH_AMR: /* AMR */
/**
* TODO: AMR requires a dedicated loop,
* which will be implemented later...
*/
LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet\n");
return -ENOTSUP;
default:
LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode);
return -EINVAL;
}
/* Shift buffer by 4 bursts for interleaving */
memcpy(buffer, buffer + 232, 232);
memcpy(buffer + 232, buffer + 464, 232);
/* Shift burst mask */
*mask = *mask << 2;
/* Check decoding result */
if (rc < 4) {
LOGP(DSCHD, LOGL_ERROR, "Received bad TCH frame ending at "
"fn=%u on %s (rc=%d)\n", fn, lchan_desc->name, rc);
/* Send BFI */
goto bfi;
} else if (rc == GSM_MACBLOCK_LEN) {
/* Skip decoding of the next 2 stolen bursts */
lchan->dl_ongoing_facch = true;
/* Calculate TDMA frame number of the first burst */
lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
fn, true); /* FACCH/H */
/* FACCH/H received, forward to the higher layers */
sched_send_dt_ind(trx, ts, lchan, l2, GSM_MACBLOCK_LEN,
n_errors, false, false);
/* 1/2 BFI */
goto bfi;
} else {
/* A good TCH frame received */
l2_len = rc;
}
/* Calculate TDMA frame number of the first burst */
lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
fn, false); /* TCH/H */
/* Send a traffic frame to the higher layers */
return sched_send_dt_ind(trx, ts, lchan, l2, l2_len,
n_errors, false, true);
bfi_shift:
/* Shift buffer */
memcpy(buffer, buffer + 232, 232);
memcpy(buffer + 232, buffer + 464, 232);
/* Shift burst mask */
*mask = *mask << 2;
bfi:
/* Didn't try to decode */
if (n_errors < 0)
n_errors = 116 * 2;
/* Calculate TDMA frame number of the first burst */
lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
fn, false); /* TCH/H */
/* BFI is not applicable in signalling mode */
if (lchan->tch_mode == GSM48_CMODE_SIGN)
return sched_send_dt_ind(trx, ts, lchan, NULL, 0,
n_errors, true, false);
/* Bad frame indication */
l2_len = sched_bad_frame_ind(l2, lchan);
/* Send a BFI frame to the higher layers */
return sched_send_dt_ind(trx, ts, lchan, l2, l2_len,
n_errors, true, true);
}
int tx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid)
{
const struct trx_lchan_desc *lchan_desc;
ubit_t burst[GSM_BURST_LEN];
ubit_t *buffer, *offset;
const uint8_t *tsc;
uint8_t *mask;
size_t l2_len;
int rc;
/* Set up pointers */
lchan_desc = &trx_lchan_desc[lchan->type];
mask = &lchan->tx_burst_mask;
buffer = lchan->tx_bursts;
if (bid > 0) {
/* Align to the first burst */
if (*mask == 0x00)
return 0;
goto send_burst;
}
if (*mask == 0x00) {
/* Align transmission of the first FACCH/H frame */
if (lchan->tch_mode == GSM48_CMODE_SIGN)
if (!sched_tchh_facch_start(lchan->type, fn, 1))
return 0;
}
/* Shift buffer by 2 bursts back for interleaving */
memcpy(buffer, buffer + 232, 232);
/* Also shift TX burst mask */
*mask = *mask << 2;
/* If FACCH/H blocks are still pending */
if (lchan->ul_facch_blocks > 2) {
memcpy(buffer + 232, buffer + 464, 232);
goto send_burst;
}
/* Check the current TCH mode */
switch (lchan->tch_mode) {
case GSM48_CMODE_SIGN:
case GSM48_CMODE_SPEECH_V1: /* HR */
l2_len = GSM_HR_BYTES + 1;
break;
case GSM48_CMODE_SPEECH_AMR: /* AMR */
/**
* TODO: AMR requires a dedicated loop,
* which will be implemented later...
*/
LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet, "
"dropping frame...\n");
/* Forget this primitive */
sched_prim_drop(lchan);
return -ENOTSUP;
default:
LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u, "
"dropping frame...\n", lchan->tch_mode);
/* Forget this primitive */
sched_prim_drop(lchan);
return -EINVAL;
}
/* Determine payload length */
if (PRIM_IS_FACCH(lchan->prim)) {
l2_len = GSM_MACBLOCK_LEN; /* FACCH */
} else if (lchan->prim->payload_len != l2_len) {
LOGP(DSCHD, LOGL_ERROR, "Primitive has odd length %zu "
"(expected %zu for TCH or %u for FACCH), so dropping...\n",
lchan->prim->payload_len, l2_len, GSM_MACBLOCK_LEN);
/* Forget this primitive */
sched_prim_drop(lchan);
return -EINVAL;
}
/* Encode the payload */
rc = gsm0503_tch_hr_encode(buffer, lchan->prim->payload, l2_len);
if (rc) {
LOGP(DSCHD, LOGL_ERROR, "Failed to encode L2 payload\n");
/* Forget this primitive */
sched_prim_drop(lchan);
return -EINVAL;
}
/* A FACCH/H frame occupies 6 bursts */
if (PRIM_IS_FACCH(lchan->prim))
lchan->ul_facch_blocks = 6;
send_burst:
/* Determine which burst should be sent */
offset = buffer + bid * 116;
/* Update mask */
*mask |= (1 << bid);
/* Choose proper TSC */
tsc = sched_nb_training_bits[trx->tsc];
/* Compose a new burst */
memset(burst, 0, 3); /* TB */
memcpy(burst + 3, offset, 58); /* Payload 1/2 */
memcpy(burst + 61, tsc, 26); /* TSC */
memcpy(burst + 87, offset + 58, 58); /* Payload 2/2 */
memset(burst + 145, 0, 3); /* TB */
LOGP(DSCHD, LOGL_DEBUG, "Transmitting %s fn=%u ts=%u burst=%u\n",
lchan_desc->name, fn, ts->index, bid);
/* Forward burst to transceiver */
sched_trx_handle_tx_burst(trx, ts, lchan, fn, burst);
/* In case of a FACCH/H frame, one block less */
if (lchan->ul_facch_blocks)
lchan->ul_facch_blocks--;
if ((*mask & 0x0f) == 0x0f) {
/**
* If no more FACCH/H blocks pending,
* confirm data / traffic sending
*/
if (!lchan->ul_facch_blocks)
sched_send_dt_conf(trx, ts, lchan, fn,
PRIM_IS_TCH(lchan->prim));
/* Forget processed primitive */
sched_prim_drop(lchan);
}
return 0;
}

@ -463,7 +463,7 @@ static void sched_trx_reset_lchan(struct trx_lchan_state *lchan)
/* TCH specific variables */
if (CHAN_IS_TCH(lchan->type)) {
lchan->dl_ongoing_facch = 0;
lchan->ul_ongoing_facch = 0;
lchan->ul_facch_blocks = 0;
lchan->tch_mode = GSM48_CMODE_SIGN;

@ -171,9 +171,9 @@ struct trx_lchan_state {
uint8_t tch_mode;
/*! \brief FACCH/H on downlink */
uint8_t dl_ongoing_facch;
/*! \brief FACCH/H on uplink */
uint8_t ul_ongoing_facch;
bool dl_ongoing_facch;
/*! \brief pending FACCH/H blocks on Uplink */
uint8_t ul_facch_blocks;
struct {
/*! \brief Number of RSSI values */

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