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libosmo-abis/src/trau/trau_pcu_ericsson.c

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/*
* (C) 2022 by sysmocom - s.f.m.c. GmbH
* Author: Philipp Maier <pmaier@sysmocom.de>
* All Rights Reserved
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
*/
#include <stdio.h>
#include <stdint.h>
#include <errno.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/bitvec.h>
#include <osmocom/core/crc16gen.h>
#include <osmocom/core/logging.h>
#include <arpa/inet.h>
#include <osmocom/trau/trau_pcu_ericsson.h>
#include <osmocom/gsm/gsm0502.h>
#define E1_TRAU_BITS_MSGB 2048
/* CRC polynom for CS1 TRAU frame protection: X^16+X^12+X^5+1 */
const struct osmo_crc16gen_code cs1_crc16 = { 16, 0x1021, 0, 0xffff };
/* Frame Type C-bits: C1..C5 */
#define PCU_TRAU_ER_FT_PCU_SYNC_IND 0x0F
#define PCU_TRAU_ER_FT_CCU_SYNC_IND 0x15
#define PCU_TRAU_ER_FT_DATA_IND 0x1A
#define PCU_TRAU_ER_FT_DATA9_IND 0x04
const ubit_t T_bits_16[] = {
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, /* (+8 variable bits) */
};
const ubit_t T_bits_64[] = {
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, /* (+16 variable bits) */
};
/* Calc an odd parity bit over a given number of bits */
static ubit_t calc_parity(const ubit_t *bits, size_t len)
{
size_t i;
ubit_t par = 1;
for (i = 0; i < len; i++)
par ^= bits[i];
return par;
}
/* Put data to TRAU frame, skip T bits */
static int put_trau_data(ubit_t *bits, size_t bits_len,
const ubit_t *bits_map, size_t bits_map_len, const ubit_t *bits_in, size_t offs, size_t len)
{
size_t bit_count = 0;
size_t i = 0;
/* The bits map must always cover all bits, so it must not be shorter
* then the bits we are about to parse. Also the offset must not be
* greater then the length of the bits */
if (bits_len > bits_map_len)
return -EINVAL;
if (bits_len <= offs)
return -EINVAL;
/* Advance to the position where the data is stored */
bits += offs;
bits_len -= offs;
bits_map += offs;
bits_map_len -= offs;
do {
/* Do not exceed bits or bits_map */
if (bit_count > bits_len)
return -EINVAL;
if (bit_count > bits_map_len)
return -EINVAL;
/* Do not exceed output buffer */
if (i > bits_len)
return -EINVAL;
/* skip positions that have already bits set. */
if (*bits_map == 0) {
*bits = *bits_in;
bits_in++;
i++;
}
bit_count++;
bits++;
bits_map++;
} while (i < len);
return 0;
}
/* Put an uint32 value to TRAU frame */
static int put_trau_uint32(ubit_t *bits, size_t bits_len,
const ubit_t *bits_map, size_t bits_map_len, uint32_t value, size_t offs, size_t len)
{
ubit_t buf[32];
OSMO_ASSERT(len < 32);
memset(buf, 0, sizeof(buf));
value = htonl(value);
osmo_pbit2ubit_ext(buf, 0, (ubit_t *) &value, 32 - len, len, 0);
return put_trau_data(bits, bits_len, bits_map, bits_map_len, buf, offs, len);
}
/* Get data from TRAU frame, ignore T bits */
static int get_trau_data(ubit_t *bits_out, size_t bits_out_len,
const ubit_t *bits, size_t bits_len,
const ubit_t *bits_map, size_t bits_map_len, size_t offs, size_t len)
{
size_t bit_count = 0;
size_t i = 0;
/* (see above) */
if (bits_len > bits_map_len)
return -EINVAL;
if (bits_len <= offs)
return -EINVAL;
/* Advance to the position where the data is located */
bits += offs;
bits_map += offs;
bits_len -= offs;
bits_map_len -= offs;
/* Extract bits from TRAU frame */
do {
/* Do not exceed bits or bits_map */
if (bit_count > bits_len)
return -EINVAL;
if (bit_count > bits_map_len)
return -EINVAL;
/* Do not exceed output buffer */
if (i > bits_out_len)
return -EINVAL;
if (*bits_map == 0) {
*bits_out = *bits;
bits_out++;
i++;
}
bit_count++;
bits++;
bits_map++;
} while (i < len);
return 0;
}
/* Get an uint32 value from TRAU frame */
static uint32_t get_trau_uint32(const ubit_t *bits, size_t bits_len,
const ubit_t *bits_map, size_t bits_map_len, size_t offs, uint8_t len)
{
ubit_t buf[32];
uint32_t result = 0;
int rc;
OSMO_ASSERT(len < 32);
memset(buf, 0, sizeof(buf));
rc = get_trau_data(buf, sizeof(buf), bits, bits_len, bits_map, bits_map_len, offs, len);
if (rc < 0)
return 0;
osmo_ubit2pbit_ext((pbit_t *) &result, 32 - len, buf, 0, len, 0);
result = ntohl(result);
return result;
}
/* Set Time adjustment bits, add 4 more bits in case of delay */
static int set_timing_ajustment_bits_16(ubit_t *trau_bits, enum time_adj_val tav)
{
/* Note: This sets the tail bits and returns the final length of the final length of the TRAU frame. The caller
* must then make sure that the frame is transitted with the returned length to achieve correct timing
* alignment. */
switch (tav) {
case TIME_ADJ_NONE:
return 320;
case TIME_ADJ_DELAY_250us:
return 320 + 4;
case TIME_ADJ_ADVANCE_250us:
/* Note: the 16 removed bits are not transmitted. */
return 320 - 4;
}
return -EINVAL;
}
/* Set Time adjustment bits, add 16 more bits in case of delay */
static int set_timing_ajustment_bits_64(ubit_t *trau_bits, enum time_adj_val tav)
{
/* (see comment above) */
switch (tav) {
case TIME_ADJ_NONE:
return 1280;
case TIME_ADJ_DELAY_250us:
return 1280 + 16;
case TIME_ADJ_ADVANCE_250us:
/* Note: the 16 removed bits are not transmitted. */
return 1280 - 16;
}
return -EINVAL;
}
/* Decode an 8-byte access burst data structure */
static int decode_ab(struct er_gprs_ab *ab, uint8_t *ab_bytes)
{
memset(ab, 0, sizeof(*ab));
/* Type 1/2 specific fields */
if ((ab_bytes[0] & 0x1f) == 0x1f) {
ab->ab_type = 1;
ab->u.type_1.crc = ab_bytes[0] >> 5 & 0x07;
ab->u.type_1.burst_qual = ab_bytes[2];
ab->u.type_1.frame_qual = ab_bytes[3];
} else if ((ab_bytes[0] & 0x1f) == 0) {
ab->ab_type = 2;
ab->u.type_2.abi = ab_bytes[0] >> 5 & 0x07;
ab->u.type_2.type = ab_bytes[3] >> 6 & 0x03;
} else
return -EINVAL;
/* Common fields */
ab->rxlev = ab_bytes[1];
ab->acc_delay = (ab_bytes[4] << 2) & 0x0300;
ab->acc_delay |= ab_bytes[5];
ab->data = (ab_bytes[6] << 3) & 0x0700;
ab->data |= ab_bytes[7];
return 0;
}
static int enc_pcu_sync_ind_16(ubit_t *trau_bits, struct er_pcu_sync_ind *ind)
{
/* 16kbps PCU-SYNC-IND TRAU frame format:
* Direction: PCU => CCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC 0. 0 0 0 0 0
* 1 0 0 0 0 0 0 0
* 0 D15 D16 D17 D18 D19 D20 D21 PSEQ (offset 41)
* 1 D22 D23 D24 D25 D26 D27 D28
* D29 D30 D31 D32 D33 D34 D35 D36
* 1 D37 D38 D39 D40 D41 D42 D43 SS (offset 65)
* D44 D45 D46 D47 D48 D49 D50 D51
* 1 1 1 1 1 1 1 1
* 1 D60 D61 D62 D63 D64 D65 D66 FN UL (offset 89)
* 1 D67 D68 D69 D70 D71 D72 D73
* D74 D75 D76 D77 D78 D79 D80 D81
* 1 D82 D83 D84 D85 D86 D87 D88 FN SS (offset 113)
* D89 D90 D91 D92 D93 D94 D95 D96
* 1 1 1 1 1 1 1 1
* 1 D105 D106 D107 D108 D109 D110 D111 FN DL (offset 137)
* 1 D112 D113 D114 D115 D116 D117 D118
* D119 D120 D121 D122 D123 D124 D125 D126
* 1 D127 D128 D129 D130 D131 D132 D133 LS (offset 161)
* D134 D135 D136 D137 D138 D139 D140 D141
* 1 1 1 1 1 1 1 1
* 1 1 1 ...
* ... 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 TA1 TA2 TA3 TA4 (bit 319)
* TA5* TA6* TA7* TA8*
*
* "*" = additional TA bits to delay the frame
* C = Control bits
* D = Data bits
* PC = Parity over C-Bits (odd) */
pbit_t c_1_5 = PCU_TRAU_ER_FT_PCU_SYNC_IND;
int rc;
/* C-Bits */
osmo_pbit2ubit_ext(trau_bits, 17, &c_1_5, 0, 5, 1);
osmo_pbit2ubit_ext(trau_bits, 22, (pbit_t *) &ind->tav, 0, 2, 1);
if (ind->ul_frame_err)
trau_bits[24] = 0;
trau_bits[25] = calc_parity(trau_bits + 17, 8);
/* D-Bits */
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->pseq, 41, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->ss, 65, 15);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->fn_ul, 89, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->fn_ss, 113, 15);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->fn_dl, 137, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), ind->ls, 161, 15);
if (rc < 0)
return -EINVAL;
return set_timing_ajustment_bits_16(trau_bits, ind->tav);
}
int enc_pcu_data_ind_16(ubit_t *trau_bits, struct er_pcu_data_ind *ind)
{
/* 16kbps PCU-DATA-IND TRAU frame format:
* Direction: PCU => CCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC E1 E2 E3 E4 E5 E6
* E7 E8 E9 E10 E11 E12 E13 E14
* E15 E16 PE D1 D2 D3 D4 D5
* D6 D7 D8 D9 D10 D11 D12 D13
* D14 D15 D16 ...
* ... D267 D268 D269
* D270 D271 D272 D273 TA1 TA2 TA3 TA4 (bit 319)
* TA5* TA6* TA7* TA8*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
pbit_t c_1_5 = PCU_TRAU_ER_FT_DATA_IND;
/* C-Bits */
osmo_pbit2ubit_ext(trau_bits, 17, &c_1_5, 0, 5, 1);
osmo_pbit2ubit_ext(trau_bits, 22, (pbit_t *) &ind->tav, 0, 2, 1);
if (ind->ul_frame_err)
trau_bits[24] = 0;
trau_bits[25] = calc_parity(trau_bits + 17, 8);
/* Set coding scheme (E1-E2) */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
trau_bits[26] = 0;
trau_bits[27] = 0;
break;
case CS_OR_HDR_CS2:
trau_bits[26] = 0;
trau_bits[27] = 1;
break;
default:
/* NOTE: The 16K TRAU frames do not have enough bandwidth to
* support coding schemes other than CS1 and CS2 */
/* NOTE: Access bursts (AB) are uplink-only. */
return -EINVAL;
}
/* Set demodulation in uplink (E3-E4) */
switch (ind->ul_chan_mode) {
case ER_UL_CHMOD_NB_GMSK:
case ER_UL_CHMOD_NB_UNKN:
trau_bits[28] = 0;
trau_bits[29] = 0;
break;
case ER_UL_CHMOD_AB:
trau_bits[28] = 0;
trau_bits[29] = 1;
break;
case ER_UL_CHMOD_AB_UNKN:
trau_bits[28] = 1;
trau_bits[29] = 0;
break;
case ER_UL_CHMOD_VOID:
trau_bits[28] = 1;
trau_bits[29] = 1;
break;
default:
return -EINVAL;
}
/* Timing offset (E5-E12, 8 bit value, MSB first) */
osmo_pbit2ubit_ext(trau_bits, 30, (pbit_t *) &ind->timing_offset, 0, 8, 0);
/* Power control (E13-E16, 4 bit value, MSB first, 2dB steps) */
osmo_pbit2ubit_ext(trau_bits, 38, (pbit_t *) &ind->atten_db, 4, 4, 0);
/* Parity (odd) over coding scheme, demodulation, timing offset and
* power control bits (E1-E16) */
trau_bits[42] = calc_parity(trau_bits + 26, 16);
/* Data bits */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
osmo_pbit2ubit_ext(trau_bits, 43, (pbit_t *) ind->data, 0, 184, 1);
osmo_crc16gen_set_bits(&cs1_crc16, trau_bits + 43, 184, trau_bits + 43 + 184);
break;
case CS_OR_HDR_CS2:
osmo_pbit2ubit_ext(trau_bits, 43, (pbit_t *) ind->data, 0, 271, 1);
break;
default:
/* NOTE: The 16K TRAU frames do not have enough bandwidth to
* support coding schemes other than CS1 and CS2 */
return -EINVAL;
}
return set_timing_ajustment_bits_16(trau_bits, ind->tav);
}
/*! encode an 16k Ericsson GPRS (GSL) TRAU frame.
* \param[out] bits caller-allocated memory for unpacked output bits (320+4).
* \param[in] fr input data structure describing TRAU frame.
* \return number of bits encoded. */
int er_gprs_trau_frame_encode_16k(ubit_t *bits, struct er_gprs_trau_frame *fr)
{
/* Prepare frame: first 16 bits set 0, remaining bits set to 1 */
memset(bits, 0, 16);
memset(bits + 16, 1, 320 + 4 - 16);
switch (fr->type) {
case ER_GPRS_TRAU_FT_SYNC:
return enc_pcu_sync_ind_16(bits, &fr->u.pcu_sync_ind);
case ER_GPRS_TRAU_FT_DATA:
return enc_pcu_data_ind_16(bits, &fr->u.pcu_data_ind);
default:
return -EINVAL;
}
return -EINVAL;
}
static int dec_ccu_sync_ind_16(struct er_ccu_sync_ind *ind, const ubit_t *trau_bits)
{
/* 16kbps CCU-SYNC-IND TRAU frame format:
* Direction: CCU => PCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC E1 PE 1 1 1 1
* 1 0 0 0 0 0 0 0
* 0 D13 D14 D15 D16 D17 D18 D19 PSEQ (offset 41)
* 1 D20 D21 D22 D23 D24 D25 D26
* D27 D28 D29 D30 D31 D32 D33 D34
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 D58 D59 D60 D61 D62 D63 D64 AFN UL (offset 89)
* 1 D65 D66 D67 D68 D69 D70 D71
* D72 D73 D74 D75 D76 D77 D78 D79
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 D103 D104 D105 D106 D107 D108 D109 AFN DL (offset 137)
* 1 D110 D111 D112 D113 D114 D115 D116
* D117 D118 D119 D120 D121 D122 D123 D124
* 1 1 1 1 1 1 1 1
* 1 1 1 ...
* ... 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 TA1 TA2 (bit 319)
* TA3* TA4*
*
* "*" = additional TA bits to delay the frame
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
size_t i;
/* Validate sync pattern (extended) */
for (i = 0; i < 19; i++) {
if (trau_bits[16 + i * 16] != 1) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-16: invalid sync pattern (T1 at position %zu != 1)\n", i);
return -EINVAL;
}
}
/* Validate C-Bits */
if (calc_parity(trau_bits + 17, 8) != trau_bits[25]) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-16: invalid parity (C1-C8)\n");
return -EINVAL;
}
/* TAV (C7-C9) */
osmo_ubit2pbit_ext((pbit_t *) &ind->tav, 0, trau_bits, 22, 2, 1);
/* Downlink frame error, DFE (C8) */
if (trau_bits[24] == 0)
ind->dfe = true;
/* Check (odd) parity of E1 bit */
if (trau_bits[26] != ((~trau_bits[27]) & 1)) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-16: invalid parity (E1)\n");
return -EINVAL;
}
/* Downlink Block error, DBE (E1) */
if (trau_bits[26] == 0)
ind->dbe = true;
/* D bits */
ind->pseq = get_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), 41, 22);
ind->afn_ul = get_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), 89, 22);
ind->afn_dl = get_trau_uint32(trau_bits, 320, T_bits_16, sizeof(T_bits_16), 137, 22);
return 0;
}
static int dec_ccu_data_ind_16(struct er_ccu_data_ind *ind, const ubit_t *trau_bits)
{
/* 16kbps CCU-DATA-IND TRAU frame format:
* Direction: CCU => PCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* PC E1 E2 E3 E4 E5 E6 E7
* E8 E9 E10 E11 E12 E13 E14 E15
* E16 E17 E18 E19 PE D1 D2 D3
* D4 D5 D6 D7 D8 D9 D10 D11
* D12 D13 D14 ...
* ... D267 D268 D269
* D270 D271 D272 D273 TA1 TA2 TA3 TA4 (bit 319)
* TA5* TA6* TA7* TA8*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
uint8_t sfq = 0;
uint8_t eadd = 0;
uint8_t e_2_4 = 0;
int rc;
int i;
/* Validate C-Bits */
if (calc_parity(trau_bits + 17, 7) != trau_bits[24]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: invalid parity (C1-C7)\n");
return -EINVAL;
}
/* TAV (C6-C7) */
osmo_ubit2pbit_ext((pbit_t *) &ind->tav, 0, trau_bits, 22, 2, 1);
/* Validate E-Bits */
if (calc_parity(trau_bits + 25, 19) != trau_bits[44]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: invalid parity (E1-E19)\n");
return -EINVAL;
}
/* Downlink block error (E1) */
if (trau_bits[25] == 0)
ind->dbe = true;
/* Coding scheme (E2-E4) */
osmo_ubit2pbit_ext((pbit_t *) &e_2_4, 5, trau_bits, 26, 3, 0);
switch (e_2_4) {
case 0:
ind->cs_hdr = CS_OR_HDR_CS1;
break;
case 1:
ind->cs_hdr = CS_OR_HDR_CS2;
break;
case 4:
ind->cs_hdr = CS_OR_HDR_AB;
break;
default:
/* 16kbps timeslots only support CS1, CS2 and AB are supported,
* due to bandwidth limitations. */
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: invalid codec status (E2-E4)\n");
return -EINVAL;
}
/* Soft frame quality SFQ (E5-E7, 0 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &sfq, 5, trau_bits, 29, 3, 0);
ind->u.gprs.block_qual = sfq;
/* Parity Check (E8, 1 in case of AB) */
ind->u.gprs.parity_ok = trau_bits[32];
/* RX-LEV (E9-E14, 63 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &ind->rx_lev, 2, trau_bits, 33, 6, 0);
/* Estimated access delay (E15-E17, 0 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &eadd, 5, trau_bits, 39, 3, 0);
switch (eadd) {
case 0:
/* <2 or less */
ind->est_acc_del_dev = -3;
break;
case 1:
ind->est_acc_del_dev = -1;
break;
case 2:
ind->est_acc_del_dev = 1;
break;
case 4:
ind->est_acc_del_dev = 2;
break;
case 5:
/* >2 or more */
ind->est_acc_del_dev = 3;
break;
case 6:
ind->est_acc_del_dev = 0;
break;
case 7:
ind->est_acc_del_dev = -2;
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: invalid estimated access delay (E15-E17)\n");
return -EINVAL;
}
/* Data bits */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 45, 184, 1);
rc = osmo_crc16gen_check_bits(&cs1_crc16, trau_bits + 45, 184, trau_bits + 45 + 184);
if (rc != 0) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: CRC error in CS1 block\n");
return -EINVAL;
}
ind->data_len = 23;
break;
case CS_OR_HDR_CS2:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 45, 271, 1);
ind->data_len = 34;
break;
case CS_OR_HDR_AB:
/* Note: The useful data starts at D4 and is byte-aligned inside the TRAU frame.
* The data string contains 4 items, each 8 bytes long, 32 bytes total. */
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 48, 256, 1);
ind->data_len = 32;
for (i = 0; i < 4; i++) {
rc = decode_ab(&ind->ab[i], ind->data + i * 8);
if (rc < 0)
return -EINVAL;
}
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-16: invalid cs_hdr set\n");
return -EINVAL;
}
return 0;
};
/*! decode an 16k Ericsson GPRS (GSL) TRAU frame.
* \param[out] fr caller-allocated output data structure.
* \param[in] bits unpacked input bits (320).
* \return 0 on success; negative in case of error. */
int er_gprs_trau_frame_decode_16k(struct er_gprs_trau_frame *fr, const ubit_t *bits)
{
uint8_t c_1_5 = 0;
const ubit_t expected_sync_pattern[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
int rc;
memset(fr, 0, sizeof(*fr));
/* Validate sync pattern */
if (memcmp(bits, expected_sync_pattern, ARRAY_SIZE(expected_sync_pattern)) != 0) {
LOGP(DLINP, LOGL_ERROR, "CCU-XXXX-IND-16: invalid sync pattern (T0)\n");
return -EINVAL;
}
/* Determine frame type */
osmo_ubit2pbit_ext((pbit_t *) &c_1_5, 0, bits, 17, 5, 1);
switch (c_1_5) {
case PCU_TRAU_ER_FT_CCU_SYNC_IND:
fr->type = ER_GPRS_TRAU_FT_SYNC;
rc = dec_ccu_sync_ind_16(&fr->u.ccu_sync_ind, bits);
break;
case PCU_TRAU_ER_FT_DATA_IND:
fr->type = ER_GPRS_TRAU_FT_DATA;
rc = dec_ccu_data_ind_16(&fr->u.ccu_data_ind, bits);
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-XXXX-IND-16: invalid frame type (%02x)\n", c_1_5);
rc = -EINVAL;
}
/* Ensure that we exit with predictable data in case of error. */
if (rc < 0)
memset(fr, 0, sizeof(*fr));
return rc;
}
/* Extract the CPS field from a given block, block must have minimum length of 5 bytes.
* See also: 3GPP TS 44.060, section 10.3a.3 and section 10.3a.4 */
static int cps_from_mcs_block(uint8_t *block, enum er_cs_or_hdr cs_hdr, bool uplink)
{
uint8_t cps;
if (uplink) {
switch (cs_hdr) {
case CS_OR_HDR_HDR1:
cps = block[4] & 0x1f;
break;
case CS_OR_HDR_HDR2:
cps = (block[2] >> 6) & 0x3;
cps |= block[3] << 2 & 0x4;
break;
case CS_OR_HDR_HDR3:
cps = (block[2] >> 6) & 0x3;
cps |= block[3] << 2 & 0xC;
break;
default:
return -EINVAL;
}
} else {
switch (cs_hdr) {
case CS_OR_HDR_HDR1:
cps = (block[4] >> 3) & 0x1f;
break;
case CS_OR_HDR_HDR2:
cps = (block[3] >> 1) & 0x07;
break;
case CS_OR_HDR_HDR3:
cps = (block[3] >> 1) & 0x0f;
break;
default:
return -EINVAL;
}
}
return cps;
}
/* Determine the MCS block type from a given CPS value.
* See also: 3GPP TS 44.060, section 10.4.8a */
static int mcs_from_cps(uint8_t cps, enum er_cs_or_hdr cs_hdr)
{
switch (cs_hdr) {
case CS_OR_HDR_HDR1:
if (cps <= 0x0A)
return 9;
if (cps <= 0x13)
return 8;
if (cps <= 0x1C)
return 7;
return -EINVAL;
break;
case CS_OR_HDR_HDR2:
if (cps <= 0x03 || cps == 0x06 || cps == 0x07)
return 6;
if (cps == 4 || cps == 5)
return 5;
return -EINVAL;
break;
case CS_OR_HDR_HDR3:
if (cps <= 0x02)
return 4;
if (cps <= 0x08)
return 3;
if (cps == 0x09 || cps == 0x0A || cps == 0x0D || cps == 0x0E)
return 2;
if (cps == 0x0B || cps == 0x0C)
return 1;
return -EINVAL;
break;
default:
return -EINVAL;
}
}
static int enc_pcu_sync_ind_64(ubit_t *trau_bits, struct er_pcu_sync_ind *ind)
{
/* 64kbps PCU-SYNC-IND TRAU frame format:
* Direction: PCU => CCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 D96 D97 D98 D99 D100 D101
* D102 D103 D104 D105 D106 D107 D108 D109
* D110 D111 D112 D113 D114 D115 D116 D117
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* D133 D134 D135 D136 D137 D138 D139 D140
* D141 D142 D143 D144 D145 D146 D147 D148
* 1 1 1 1 1 1 1 1
* 1 1 D159 D160 D161 D162 D163 D164
* D165 D166 D167 D168 D169 D170 D171 D172
* D173 D174 D175 D176 D177 D178 D179 D180
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* D196 D197 D198 D199 D200 D201 D202 D203
* D204 D205 D206 D207 D208 D209 D210 D211
* 1 1 1 1 1 1 1 1
* 1 1 D222 D223 D224 D225 D226 D227
* D228 D229 D230 D231 D232 D233 D234 D235
* D236 D237 D238 D239 D340 D241 D242 D243
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* D259 D260 D261 D262 D263 D264 D265 D266
* D267 D268 D269 D270 D271 D272 D273 D274
* 1 1 1 1 1 1 1 1
* 1 1 1 ...
* ... 1 1 1
* 1 1 1 1 1 1 1 1
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* "*" = additional TA bits to delay the frame
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
pbit_t c_1_5 = PCU_TRAU_ER_FT_PCU_SYNC_IND;
int rc;
/* C-Bits */
osmo_pbit2ubit_ext(trau_bits, 65, &c_1_5, 0, 5, 1);
osmo_pbit2ubit_ext(trau_bits, 70, (pbit_t *) &ind->tav, 0, 2, 1);
if (ind->ul_frame_err)
trau_bits[73] = 0;
trau_bits[74] = calc_parity(trau_bits + 65, 8);
/* unused D-bits are initialized in er_gprs_trau_frame_encode */
/* D-Bits */
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->pseq, 170, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->ss, 208, 16);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->fn_ul, 234, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->fn_ss, 272, 15);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->fn_dl, 298, 22);
if (rc < 0)
return -EINVAL;
rc = put_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), ind->ls, 336, 16);
if (rc < 0)
return -EINVAL;
return set_timing_ajustment_bits_64(trau_bits, ind->tav);
}
int enc_pcu_data_ind_64(ubit_t *trau_bits, struct er_pcu_data_ind *ind, uint8_t mcs)
{
/* 64kbps PCU-DATA-IND TRAU frame format:
* Direction: PCU => CCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC E1 E2 E3 E4 E5 E6
* E7 E8 E9 E10 E11 E12 E13 E14
* E15 E16 E17 E18 E19 E20 E21 E22
* E23 E24 E25 E26 E27 E28 E29 E30
* E31 E32 E33 E34 E35 E36 PE S1
* S2 S3 S4 S5 S6 S7 S8 S9
* S10 S11 S12 S13 S14 S15 S16 S17
* S18 S19 S20 S21 D1 D2 D3 D4
* D5 D6 D7 D8 D9 D10 D11 D12
* D13 D14 D15 D16 D17 D18 D19 D20
* D21 D22 D23 ...
* ... D1130 D1131 D1132
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
pbit_t c_1_5 = PCU_TRAU_ER_FT_DATA_IND;
/* C-Bits */
osmo_pbit2ubit_ext(trau_bits, 65, &c_1_5, 0, 5, 1);
osmo_pbit2ubit_ext(trau_bits, 70, (pbit_t *) &ind->tav, 0, 2, 1);
if (ind->ul_frame_err)
trau_bits[73] = 0;
trau_bits[74] = calc_parity(trau_bits + 65, 8);
/* Set coding scheme (E1-E3) */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
trau_bits[74] = 0;
trau_bits[75] = 0;
trau_bits[76] = 1;
break;
case CS_OR_HDR_CS2:
trau_bits[74] = 0;
trau_bits[75] = 1;
trau_bits[76] = 0;
break;
case CS_OR_HDR_CS3:
trau_bits[74] = 0;
trau_bits[75] = 1;
trau_bits[76] = 1;
break;
case CS_OR_HDR_CS4:
trau_bits[74] = 1;
trau_bits[75] = 0;
trau_bits[76] = 0;
break;
case CS_OR_HDR_HDR1:
trau_bits[74] = 1;
trau_bits[75] = 0;
trau_bits[76] = 1;
break;
case CS_OR_HDR_HDR2:
trau_bits[74] = 1;
trau_bits[75] = 1;
trau_bits[76] = 0;
break;
case CS_OR_HDR_HDR3:
trau_bits[74] = 1;
trau_bits[75] = 1;
trau_bits[76] = 1;
break;
default:
/* NOTE: Access bursts (AB) are uplink-only. */
return -EINVAL;
}
/* Set demodulation in uplink (E4-E6) */
switch (ind->ul_chan_mode) {
case ER_UL_CHMOD_VOID:
trau_bits[77] = 0;
trau_bits[78] = 0;
trau_bits[79] = 0;
break;
case ER_UL_CHMOD_NB_GMSK:
trau_bits[77] = 0;
trau_bits[78] = 0;
trau_bits[79] = 1;
break;
case ER_UL_CHMOD_NB_UNKN:
trau_bits[77] = 0;
trau_bits[78] = 1;
trau_bits[79] = 0;
break;
case ER_UL_CHMOD_AB:
trau_bits[77] = 0;
trau_bits[78] = 1;
trau_bits[79] = 1;
break;
case ER_UL_CHMOD_AB_UNKN:
trau_bits[77] = 1;
trau_bits[78] = 0;
trau_bits[79] = 0;
break;
default:
return -EINVAL;
}
/* Timing offset (E7-E14, 8 bit value, MSB first) */
osmo_pbit2ubit_ext(trau_bits, 80, (pbit_t *) &ind->timing_offset, 0, 8, 0);
/* Power control (E33-E36, 4 bit value, MSB first, 2dB steps) */
osmo_pbit2ubit_ext(trau_bits, 106, (pbit_t *) &ind->atten_db, 4, 4, 0);
/* Parity (odd) over coding scheme, demodulation, timing offset and
* power control bits (E1-E36) */
trau_bits[110] = calc_parity(trau_bits + 74, 36);
/* Data bits */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 184, 1);
osmo_crc16gen_set_bits(&cs1_crc16, trau_bits + 132, 184, trau_bits + 132 + 184);
break;
case CS_OR_HDR_CS2:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 271, 1);
break;
case CS_OR_HDR_CS3:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 315, 1);
break;
case CS_OR_HDR_CS4:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 431, 1);
break;
case CS_OR_HDR_HDR1:
case CS_OR_HDR_HDR2:
case CS_OR_HDR_HDR3:
switch (mcs) {
case 1:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 209, 1);
break;
case 2:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 257, 1);
break;
case 3:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 329, 1);
break;
case 4:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 385, 1);
break;
case 5:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 478, 1);
break;
case 6:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 622, 1);
break;
case 7:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 940, 1);
break;
case 8:
osmo_pbit2ubit_ext(trau_bits, 132, (pbit_t *) ind->data, 0, 1132, 1);
break;
}
break;
default:
/* NOTE: The 16K TRAU frames do not have enough bandwidth to
* support coding schemes other than CS1 and CS2 */
return -EINVAL;
}
return set_timing_ajustment_bits_64(trau_bits, ind->tav);
}
int enc_pcu_data_ind_64_mcs9(ubit_t *trau_bits, struct er_pcu_data_ind *ind)
{
/* 64kbps PCU-DATA-IND (MCS9) TRAU frame format:
* Direction: PCU => CCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 D1 D2 D3 D4 D5 D6 D7
* D8 D9 D10 D11 D12 D13 D14 D15
* D16 D17 D18 D19 D20 D21 D22 D23
* D24 D25 D26 D27 D28 D29 D30 D31
* D32 D33 D34 D35 D36 D37 D38 D39
* D40 D41 D42 D43 D44 D45 D46 D47
* D48 C1 C2 C3 C4 C5 C6 C7
* C8 PC E1 E2 E3 E4 E5 E6
* E7 E8 E9 PE D49 D50 D51 D52
* D53 D54 D55 D56 D57 D58 D59 D60
* D61 D62 D63 D64 D65 D66 D67 D68
* D69 D70 D71 ...
* ... D1226 D1227 D1228
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
pbit_t c_1_5 = PCU_TRAU_ER_FT_DATA9_IND;
/* NOTE: The ericsson MCS9 64K TRAU format uses a different sync
* pattern than the other 64K TRAU frame formats. To make room for
* the additional bits in MCS9 only the first 16 bits are T0 bits. */
trau_bits[16] = 1;
/* Fill headroom that normally would have T0 and T1 bits with data
* bits */
osmo_pbit2ubit_ext(trau_bits, 17, (pbit_t *) ind->data, 0, 48, 1);
/* C-Bits */
osmo_pbit2ubit_ext(trau_bits, 65, &c_1_5, 0, 5, 1);
osmo_pbit2ubit_ext(trau_bits, 70, (pbit_t *) &ind->tav, 0, 2, 1);
if (ind->ul_frame_err)
trau_bits[73] = 0;
trau_bits[74] = calc_parity(trau_bits + 65, 8);
/* Set demodulation in uplink (E1-E3) */
switch (ind->ul_chan_mode) {
case ER_UL_CHMOD_VOID:
trau_bits[74] = 0;
trau_bits[75] = 0;
trau_bits[76] = 0;
break;
case ER_UL_CHMOD_NB_GMSK:
trau_bits[74] = 0;
trau_bits[75] = 0;
trau_bits[76] = 1;
break;
case ER_UL_CHMOD_NB_UNKN:
trau_bits[74] = 0;
trau_bits[75] = 1;
trau_bits[76] = 0;
break;
case ER_UL_CHMOD_AB:
trau_bits[74] = 0;
trau_bits[75] = 1;
trau_bits[76] = 1;
break;
case ER_UL_CHMOD_AB_UNKN:
trau_bits[74] = 1;
trau_bits[75] = 0;
trau_bits[76] = 0;
break;
default:
return -EINVAL;
}
/* E4-E5 are spare bits? */
/* Power control (E6-E9, 4 bit value, MSB first, 2dB steps) */
osmo_pbit2ubit_ext(trau_bits, 79, (pbit_t *) &ind->atten_db, 4, 4, 0);
/* Parity (odd) over coding scheme, demodulation, timing offset and
* power control bits (E1-E9) */
trau_bits[83] = calc_parity(trau_bits + 74, 9);
/* Fill the rest of the block with data bits */
osmo_pbit2ubit_ext(trau_bits, 84, (pbit_t *) ind->data + 6, 0, 1180, 1);
return set_timing_ajustment_bits_64(trau_bits, ind->tav);
}
/*! encode an 64k Ericsson GPRS (GSL) TRAU frame.
* \param[out] bits caller-allocated memory for unpacked output bits (1280+16).
* \param[in] fr input data structure describing TRAU frame.
* \return number of bits encoded. */
int er_gprs_trau_frame_encode_64k(ubit_t *bits, struct er_gprs_trau_frame *fr)
{
int cps;
int mcs = 0;
enum er_cs_or_hdr cs;
/* Prepare frame: first 16 bits set 0, remaining bits set to 1 */
memset(bits, 0, 64);
memset(bits + 64, 1, 1280 + 16 - 64);
switch (fr->type) {
case ER_GPRS_TRAU_FT_SYNC:
return enc_pcu_sync_ind_64(bits, &fr->u.pcu_sync_ind);
case ER_GPRS_TRAU_FT_DATA:
cs = fr->u.pcu_data_ind.cs_hdr;
if (cs == CS_OR_HDR_HDR1 || cs == CS_OR_HDR_HDR2 || cs == CS_OR_HDR_HDR3) {
cps = cps_from_mcs_block(fr->u.pcu_data_ind.data, cs, false);
if (cps < 0)
return -EINVAL;
mcs = mcs_from_cps((uint8_t) cps, cs);
if (mcs < 0)
return -EINVAL;
}
if (mcs < 9)
return enc_pcu_data_ind_64(bits, &fr->u.pcu_data_ind, mcs);
else
return enc_pcu_data_ind_64_mcs9(bits, &fr->u.pcu_data_ind);
default:
return -EINVAL;
}
return -EINVAL;
}
static int dec_ccu_sync_ind_64(struct er_ccu_sync_ind *ind, const ubit_t *trau_bits)
{
/* 64kbps CCU-SYNC-IND TRAU frame format:
* Direction: CCU => PCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* C8 PC E1 PE 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 D94 D95 D96 D97 D98 D99
* D100 D101 D102 D103 D104 D105 D106 D107
* D108 D109 D110 D111 D112 D113 D114 D115
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 D157 D158 D159 D160 D161 D162
* D163 D164 D165 D166 D167 D168 D169 D170
* D171 D172 D173 D174 D175 D176 D177 D178
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 1 1 1 1 1 1
* 1 1 D220 D221 D222 D223 D224 D225
* D226 D227 D228 D229 D230 D231 D232 D233
* D234 D235 D236 D237 D238 D239 D240 D241
* 1 1 1 1 1 1 1 1
* 1 1 1 ...
* ... 1 1 1
* 1 1 1 1 1 1 1 1
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* "*" = additional TA bits to delay the frame
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
size_t i;
/* Validate sync pattern (extended) */
for (i = 0; i < 19; i++) {
if (trau_bits[64 + i * 64] != 1) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-64: invalid sync pattern (T1 at position %zu != 1)\n", i);
return -EINVAL;
}
}
/* Validate C-Bits */
if (calc_parity(trau_bits + 65, 8) != trau_bits[73]) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-64: invalid parity (C1-C8)\n");
return -EINVAL;
}
/* TAV (C6-C7) */
osmo_ubit2pbit_ext((pbit_t *) &ind->tav, 0, trau_bits, 70, 2, 1);
/* Downlink frame error, DFE (C8) */
if (trau_bits[72] == 0)
ind->dfe = true;
/* Check (odd) parity of E1 bit */
if (trau_bits[74] != ((~trau_bits[75]) & 1)) {
LOGP(DLINP, LOGL_ERROR, "CCU-SYNC-IND-64: invalid parity (E1)\n");
return -EINVAL;
}
/* Downlink Block error, DBE (E1) */
if (trau_bits[74] == 0)
ind->dbe = true;
/* D bits */
ind->pseq = get_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), 170, 22);
ind->afn_ul = get_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), 234, 22);
ind->afn_dl = get_trau_uint32(trau_bits, 1280, T_bits_64, sizeof(T_bits_64), 298, 22);
return 0;
}
static int dec_ccu_data_ind_64(struct er_ccu_data_ind *ind, const ubit_t *trau_bits)
{
/* 64kbps CCU-DATA-IND TRAU frame format:
* Direction: CCU => PCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 C1 C2 C3 C4 C5 C6 C7
* PC E1 E2 E3 E4 E5 E6 E7
* E8 E9 E10 E11 E12 E13 E14 E15
* E16 E17 E18 E19 E20 E21 E22 E23
* E24 E25 E26 E27 E28 E29 E30 E31
* E32 E33 E34 E35 E36 E37 E38 E39
* E40 E41 E42 E43 E44 E45 E46 E47
* E48 E49 E50 E51 E52 E53 E54 E55
* E56 E57 PE S1 S2 S3 D1 D2
* D3 D4 D5 D6 D7 D8 D9 D10
* D11 D12 D13 D14 D15 D16 D17 D18
* D19 D20 D21 ...
* ... D1136 D1137 D1138
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
uint8_t sfq = 0;
uint8_t eadd = 0;
uint8_t e_2_4 = 0;
uint8_t mean_bep = 0;
uint8_t cv_bep = 0;
int cps;
int mcs = 0;
int rc;
int i;
/* Validate C-Bits */
if (calc_parity(trau_bits + 65, 7) != trau_bits[72]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid parity (C1-C7)\n");
return -EINVAL;
}
/* TAV (C6-C7) */
osmo_ubit2pbit_ext((pbit_t *) &ind->tav, 0, trau_bits, 70, 2, 1);
/* Validate E-Bits */
if (calc_parity(trau_bits + 73, 57) != trau_bits[130]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid parity (E1-E57)\n");
return -EINVAL;
}
/* Downlink block error (E1) */
if (trau_bits[73] == 0)
ind->dbe = true;
/* Coding scheme (E2-E4) */
osmo_ubit2pbit_ext((pbit_t *) &e_2_4, 5, trau_bits, 74, 3, 0);
switch (e_2_4) {
case 0:
ind->cs_hdr = CS_OR_HDR_AB;
break;
case 1:
ind->cs_hdr = CS_OR_HDR_CS1;
break;
case 2:
ind->cs_hdr = CS_OR_HDR_CS2;
break;
case 3:
ind->cs_hdr = CS_OR_HDR_CS3;
break;
case 4:
ind->cs_hdr = CS_OR_HDR_CS4;
break;
case 5:
ind->cs_hdr = CS_OR_HDR_HDR1;
break;
case 6:
ind->cs_hdr = CS_OR_HDR_HDR2;
break;
case 7:
ind->cs_hdr = CS_OR_HDR_HDR3;
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid codec status (E2-E4)\n");
return -EINVAL;
}
/* RX-LEV (E5-E10, 63 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &ind->rx_lev, 2, trau_bits, 77, 6, 0);
/* Estimated access delay (E11-E13, 0 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &eadd, 5, trau_bits, 83, 3, 0);
switch (eadd) {
case 0:
/* <2 or less */
ind->est_acc_del_dev = -3;
break;
case 1:
ind->est_acc_del_dev = -1;
break;
case 2:
ind->est_acc_del_dev = 1;
break;
case 4:
ind->est_acc_del_dev = 2;
break;
case 5:
/* >2 or more */
ind->est_acc_del_dev = 3;
break;
case 6:
ind->est_acc_del_dev = 0;
break;
case 7:
ind->est_acc_del_dev = -2;
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid estimated access delay (E11-E13)\n");
return -EINVAL;
}
if (ind->cs_hdr == CS_OR_HDR_CS1 || ind->cs_hdr == CS_OR_HDR_CS2 || ind->cs_hdr == CS_OR_HDR_CS3
|| ind->cs_hdr == CS_OR_HDR_CS4) {
/* Soft frame quality SFQ (E14-E16, 0 in case of AB) */
osmo_ubit2pbit_ext((pbit_t *) &sfq, 5, trau_bits, 86, 3, 0);
ind->u.gprs.block_qual = sfq;
/* Parity Check (E17, 1 in case of AB) */
ind->u.gprs.parity_ok = trau_bits[89];
} else {
/* Mean BEP (E14-E20) */
osmo_ubit2pbit_ext((pbit_t *) &mean_bep, 1, trau_bits, 86, 7, 0);
ind->u.egprs.mean_bep = mean_bep;
/* CV BEP (E21-E23) */
osmo_ubit2pbit_ext((pbit_t *) &cv_bep, 5, trau_bits, 93, 3, 0);
ind->u.egprs.mean_bep = cv_bep;
/* RLC/MAC header quality (E24) */
if (trau_bits[96] == 0) {
ind->u.egprs.hdr_good = true;
/* Data block quality (E25/E26) */
if (trau_bits[97] == 0)
ind->u.egprs.data_good[0] = true;
if (trau_bits[98] == 0)
ind->u.egprs.data_good[1] = true;
} else {
ind->u.egprs.hdr_good = false;
/* A bad RLC/MAC header always means that the the data blocks
* cannot be valid. */
ind->u.egprs.data_good[0] = false;
ind->u.egprs.data_good[1] = false;
}
}
/* Data bits */
switch (ind->cs_hdr) {
case CS_OR_HDR_CS1:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 184, 1);
rc = osmo_crc16gen_check_bits(&cs1_crc16, trau_bits + 134, 184, trau_bits + 134 + 184);
if (rc != 0) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: CRC error in CS1 block\n");
return -EINVAL;
}
ind->data_len = 23;
break;
case CS_OR_HDR_CS2:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 271, 1);
ind->data_len = 34;
break;
case CS_OR_HDR_CS3:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 315, 1);
ind->data_len = 40;
break;
case CS_OR_HDR_CS4:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 431, 1);
ind->data_len = 54;
break;
case CS_OR_HDR_HDR1:
case CS_OR_HDR_HDR2:
case CS_OR_HDR_HDR3:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 40, 1);
cps = cps_from_mcs_block(ind->data, ind->cs_hdr, true);
if (cps < 0) {
LOGP(DLINP, LOGL_DEBUG,
"CCU-DATA-IND-64: unable to read CPS from data block, bad data block received?\n");
break;
}
mcs = mcs_from_cps((uint8_t) cps, ind->cs_hdr);
if (mcs < 0) {
LOGP(DLINP, LOGL_DEBUG,
"CCU-DATA-IND-64: unable to determine coding scheme (MCS) from CPS, bad data block received?\n");
break;
}
/* Note: receiving noise (and eventually bad CPS field, may
* happen from time to time and is not an error condition. */
switch (mcs) {
case 1:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 209, 1);
ind->data_len = 27;
break;
case 2:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 257, 1);
ind->data_len = 33;
break;
case 3:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 329, 1);
ind->data_len = 42;
break;
case 4:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 385, 1);
ind->data_len = 49;
break;
case 5:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 487, 1);
ind->data_len = 61;
break;
case 6:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 631, 1);
ind->data_len = 79;
break;
case 7:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 946, 1);
ind->data_len = 119;
break;
case 8:
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 134, 1138, 1);
ind->data_len = 143;
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid cs_hdr set\n");
return -EINVAL;
}
break;
case CS_OR_HDR_AB:
/* Note: The useful data starts at D13 and is byte-aligned inside the TRAU frame.
* The data string contains 4 items, each 8 bytes long, 32 bytes total. */
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, trau_bits, 144, 256, 1);
ind->data_len = 32;
for (i = 0; i < 4; i++) {
rc = decode_ab(&ind->ab[i], ind->data + i * 8);
if (rc < 0)
return -EINVAL;
}
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid cs_hdr set\n");
return -EINVAL;
}
return 0;
};
static int dec_ccu_data_ind_64_mcs9(struct er_ccu_data_ind *ind, const ubit_t *trau_bits)
{
/* 64kbps CCU-DATA-IND (MCS9) TRAU frame format:
* Direction: CCU => PCU
*
* (bit 0) 0 0 0 0 0 0 0 0
* 0 0 0 0 0 0 0 0
* 1 D1 D2 D3 D4 D5 D6 D7
* D8 D9 D10 D11 D12 D13 D14 D15
* D16 D17 D18 D19 D20 D21 D22 D23
* D24 D25 D26 D27 D28 D29 D30 D31
* D32 D33 D34 D35 D36 D37 D38 D39
* D40 D41 D42 D43 D44 D45 D46 D47
* D48 C1 C2 C3 C4 C5 C6 C7
* PC E1 E2 E3 E4 E5 E6 E7
* E8 E9 E10 E11 E12 E13 E14 E15
* E16 E17 E18 E19 E20 E21 E22 E23
* PE S1 S2 D49 D50 D51 D52 D53
* D54 D55 D56 D57 D58 D59 D60 D61
* D62 D63 D64 ...
* ... D1219 D1220 D1221
* TA1 TA2 TA3 TA4 TA5 TA6 TA7 TA8
* TA9 TA10 TA11 TA12 TA13 TA14 TA15 TA16 (bit 1279)
* TA17* TA18* TA19* TA20* TA21* TA22* TA23* TA24*
* TA25* TA26* TA27* TA28* TA29* TA30* TA31* TA32*
*
* C = Control bits
* D = Data bits
* E = Extended control bits
* PC = Parity over C-Bits (odd)
* PE = Parity over extended control bits (odd) */
ubit_t block[1234];
uint8_t eadd = 0;
uint8_t mean_bep = 0;
uint8_t cv_bep = 0;
/* Validate C-Bits */
if (calc_parity(trau_bits + 65, 7) != trau_bits[72]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid parity (C1-C7)\n");
return -EINVAL;
}
/* TAV (C6-C7) */
osmo_ubit2pbit_ext((pbit_t *) &ind->tav, 0, trau_bits, 70, 2, 1);
/* Validate E-Bits */
if (calc_parity(trau_bits + 73, 23) != trau_bits[96]) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid parity (E1-E23)\n");
return -EINVAL;
}
/* Downlink block error (E1) */
if (trau_bits[73] == 0)
ind->dbe = true;
/* MCS9 uses CS header type 1 */
ind->cs_hdr = CS_OR_HDR_HDR1;
/* RX-LEV (E2-E7) */
osmo_ubit2pbit_ext((pbit_t *) &ind->rx_lev, 2, trau_bits, 74, 6, 0);
/* Estimated access delay (E8-E10) */
osmo_ubit2pbit_ext((pbit_t *) &eadd, 5, trau_bits, 80, 3, 0);
switch (eadd) {
case 0:
/* <2 or less */
ind->est_acc_del_dev = -3;
break;
case 1:
ind->est_acc_del_dev = -1;
break;
case 2:
ind->est_acc_del_dev = 1;
break;
case 4:
ind->est_acc_del_dev = 2;
break;
case 5:
/* >2 or more */
ind->est_acc_del_dev = 3;
break;
case 6:
ind->est_acc_del_dev = 0;
break;
case 7:
ind->est_acc_del_dev = -2;
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid estimated access delay (E8-E10)\n");
return -EINVAL;
}
/* Mean BEP (E11-E17) */
osmo_ubit2pbit_ext((pbit_t *) &mean_bep, 1, trau_bits, 83, 7, 0);
ind->u.egprs.mean_bep = mean_bep;
/* CV BEP (E18-E20) */
osmo_ubit2pbit_ext((pbit_t *) &cv_bep, 5, trau_bits, 90, 3, 0);
ind->u.egprs.mean_bep = cv_bep;
/* RLC/MAC header quality (E21) */
if (trau_bits[93] == 0) {
ind->u.egprs.hdr_good = true;
/* Data block quality (E22/E23) */
if (trau_bits[94] == 0)
ind->u.egprs.data_good[0] = true;
if (trau_bits[95] == 0)
ind->u.egprs.data_good[1] = true;
} else {
/* A bad RLC/MAC header always means that the the data blocks
* cannot be valid. */
ind->u.egprs.data_good[0] = false;
ind->u.egprs.data_good[1] = false;
}
/* For capacity reasons the following fields are stripped from the
* header: Spare, RSB, CPS. This means we have to restore those
* fields to get a valid MCS9 block. See also: 3GPP TS 44.060,
* section 10.3a.4.1 */
memcpy(block, trau_bits + 17, 32);
block[32] = 0; /* CPS 0 */
block[33] = 0; /* CPS 1 */
block[34] = 0; /* CPS 2 */
block[35] = 0; /* CPS 3 */
block[36] = 0; /* CPS 4 */
block[37] = 0; /* RSB (not a resent block - guessed) */
block[38] = trau_bits[49]; /* PI */
block[39] = 0; /* Spare */
block[40] = 0; /* Spare */
block[41] = 0; /* Spare */
block[42] = 0; /* Spare */
block[43] = 0; /* Spare */
block[44] = 0; /* Spare */
block[45] = 0; /* Spare */
memcpy(block + 45, trau_bits + 50, 15);
memcpy(block + 45, trau_bits + 99, 1173);
osmo_ubit2pbit_ext((pbit_t *) &ind->data, 0, block, 0, sizeof(block), 1);
return 0;
}
/*! decode an 64k Ericsson GPRS (GSL) TRAU frame.
* \param[out] fr caller-allocated output data structure.
* \param[in] bits unpacked input bits (1280).
* \return 0 on success; negative in case of error. */
int er_gprs_trau_frame_decode_64k(struct er_gprs_trau_frame *fr, const ubit_t *bits)
{
uint8_t c_1_5 = 0;
const ubit_t expected_sync_pattern[] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1,
};
const ubit_t expected_sync_pattern_mcs9[] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1,
};
int rc;
memset(fr, 0, sizeof(*fr));
/* Determine frame type */
osmo_ubit2pbit_ext((pbit_t *) &c_1_5, 0, bits, 65, 5, 1);
/* Validate sync patern */
switch (c_1_5) {
case PCU_TRAU_ER_FT_CCU_SYNC_IND:
case PCU_TRAU_ER_FT_DATA_IND:
if (memcmp(bits, expected_sync_pattern, ARRAY_SIZE(expected_sync_pattern)) != 0) {
LOGP(DLINP, LOGL_ERROR, "CCU-XXXX-IND-64: invalid sync pattern (T0,T1)\n");
return -EINVAL;
}
break;
case PCU_TRAU_ER_FT_DATA9_IND:
if (memcmp(bits, expected_sync_pattern_mcs9, ARRAY_SIZE(expected_sync_pattern_mcs9)) != 0) {
LOGP(DLINP, LOGL_ERROR, "CCU-DATA-IND-64: invalid sync pattern (T0,T1)\n");
return -EINVAL;
}
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-XXXX-IND-64: invalid frame type (%02x)\n", c_1_5);
rc = -EINVAL;
}
/* Decode frame */
switch (c_1_5) {
case PCU_TRAU_ER_FT_CCU_SYNC_IND:
fr->type = ER_GPRS_TRAU_FT_SYNC;
rc = dec_ccu_sync_ind_64(&fr->u.ccu_sync_ind, bits);
break;
case PCU_TRAU_ER_FT_DATA_IND:
fr->type = ER_GPRS_TRAU_FT_DATA;
rc = dec_ccu_data_ind_64(&fr->u.ccu_data_ind, bits);
break;
case PCU_TRAU_ER_FT_DATA9_IND:
fr->type = ER_GPRS_TRAU_FT_DATA;
rc = dec_ccu_data_ind_64_mcs9(&fr->u.ccu_data_ind, bits);
break;
default:
LOGP(DLINP, LOGL_ERROR, "CCU-XXXX-IND-64: invalid frame type (%02x)\n", c_1_5);
rc = -EINVAL;
}
/* Ensure that we exit with predictable data in case of error. */
if (rc < 0)
memset(fr, 0, sizeof(*fr));
return rc;
}
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