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libosmocore/src/gsm/gsm48_rest_octets.c

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/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface,
* rest octet handling according to
* 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */
/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* SPDX-License-Identifier: GPL-2.0+
*
*/
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdbool.h>
#include <osmocom/core/bitvec.h>
#include <osmocom/gsm/bitvec_gsm.h>
#include <osmocom/gsm/sysinfo.h>
#include <osmocom/gsm/gsm48_arfcn_range_encode.h>
#include <osmocom/gsm/gsm48_rest_octets.h>
/* generate SI1 rest octets */
int osmo_gsm48_rest_octets_si1_encode(uint8_t *data, uint8_t *nch_pos, int is1800_net)
{
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = data;
bv.data_len = 1;
if (nch_pos) {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, *nch_pos, 5);
} else {
bitvec_set_bit(&bv, L);
}
if (is1800_net)
bitvec_set_bit(&bv, L);
else
bitvec_set_bit(&bv, H);
bitvec_spare_padding(&bv, 6);
return bv.data_len;
}
struct nch_pos {
uint8_t num_blocks;
uint8_t first_block;
};
/* 3GPP TS 44.010 Table 10.5.2.32.1b */
static const struct nch_pos si1ro_nch_positions[] = {
[0x00] = {1, 0},
[0x01] = {1, 1},
[0x02] = {1, 2},
[0x03] = {1, 3},
[0x04] = {1, 4},
[0x05] = {1, 5},
[0x06] = {1, 6},
[0x07] = {2, 0},
[0x08] = {2, 1},
[0x09] = {2, 2},
[0x0a] = {2, 3},
[0x0b] = {2, 4},
[0x0c] = {2, 5},
[0x0d] = {3, 0},
[0x0e] = {3, 1},
[0x0f] = {3, 2},
[0x10] = {3, 3},
[0x11] = {3, 4},
[0x12] = {4, 0},
[0x13] = {4, 1},
[0x14] = {4, 2},
[0x15] = {4, 3},
[0x16] = {5, 0},
[0x17] = {5, 1},
[0x18] = {5, 2},
[0x19] = {6, 0},
[0x1a] = {6, 1},
[0x1b] = {7, 0},
};
/*! Decode the 5-bit 'NCH position' field within SI1 Rest Octets.
* \param[in] value 5-bit value from SI1 rest octets
* \param[out] num_blocks Number of CCCH used for NCH
* \param[out] first_block First CCCH block used for NCH
* \returns 0 on success; negative in case of error */
int osmo_gsm48_si1ro_nch_pos_decode(uint8_t value, uint8_t *num_blocks, uint8_t *first_block)
{
if (value >= ARRAY_SIZE(si1ro_nch_positions))
return -EINVAL;
*num_blocks = si1ro_nch_positions[value].num_blocks;
*first_block = si1ro_nch_positions[value].first_block;
return 0;
}
/*! Encode the 5-bit 'NCH position' field within SI1 Rest Octets.
* \param[in] num_blocks Number of CCCH used for NCH
* \param[in] first_block First CCCH block used for NCH
* \returns 5-bit value for SI1 rest octets on success; negative in case of error */
int osmo_gsm48_si1ro_nch_pos_encode(uint8_t num_blocks, uint8_t first_block)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(si1ro_nch_positions); i++) {
if (si1ro_nch_positions[i].num_blocks == num_blocks &&
si1ro_nch_positions[i].first_block == first_block) {
return i;
}
}
return -EINVAL;
}
/* Append Repeated E-UTRAN Neighbour Cell to bitvec: see 3GPP TS 44.018 Table 10.5.2.33b.1 */
static inline bool append_eutran_neib_cell(struct bitvec *bv, const struct osmo_earfcn_si2q *e, size_t *e_offset,
uint8_t budget)
{
unsigned i, skip = 0;
size_t offset = *e_offset;
int16_t rem = budget - 6; /* account for mandatory stop bit and THRESH_E-UTRAN_high */
uint8_t earfcn_budget;
if (budget <= 6)
return false;
OSMO_ASSERT(budget <= SI2Q_MAX_LEN);
/* first we have to properly adjust budget requirements */
if (e->prio_valid) /* E-UTRAN_PRIORITY: 3GPP TS 45.008*/
rem -= 4;
else
rem--;
if (e->thresh_lo_valid) /* THRESH_E-UTRAN_low: */
rem -= 6;
else
rem--;
if (e->qrxlm_valid) /* E-UTRAN_QRXLEVMIN: */
rem -= 6;
else
rem--;
if (rem < 0)
return false;
/* now we can proceed with actually adding EARFCNs within adjusted budget limit */
for (i = 0; i < e->length; i++) {
if (e->arfcn[i] != OSMO_EARFCN_INVALID) {
if (skip < offset) {
skip++; /* ignore EARFCNs added on previous calls */
} else {
earfcn_budget = 17; /* compute budget per-EARFCN */
if (OSMO_EARFCN_MEAS_INVALID == e->meas_bw[i])
earfcn_budget++;
else
earfcn_budget += 4;
if (rem - earfcn_budget < 0)
break;
else {
(*e_offset)++;
rem -= earfcn_budget;
if (rem < 0)
return false;
bitvec_set_bit(bv, 1); /* EARFCN: */
bitvec_set_uint(bv, e->arfcn[i], 16);
if (OSMO_EARFCN_MEAS_INVALID == e->meas_bw[i])
bitvec_set_bit(bv, 0);
else { /* Measurement Bandwidth: 9.1.54 */
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, e->meas_bw[i], 3);
}
}
}
}
}
/* stop bit - end of EARFCN + Measurement Bandwidth sequence */
bitvec_set_bit(bv, 0);
/* Note: we don't support different EARFCN arrays each with different priority, threshold etc. */
if (e->prio_valid) {
/* E-UTRAN_PRIORITY: 3GPP TS 45.008*/
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, e->prio, 3);
} else {
bitvec_set_bit(bv, 0);
}
/* THRESH_E-UTRAN_high */
bitvec_set_uint(bv, e->thresh_hi, 5);
if (e->thresh_lo_valid) {
/* THRESH_E-UTRAN_low: */
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, e->thresh_lo, 5);
} else {
bitvec_set_bit(bv, 0);
}
if (e->qrxlm_valid) {
/* E-UTRAN_QRXLEVMIN: */
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, e->qrxlm, 5);
} else {
bitvec_set_bit(bv, 0);
}
return true;
}
static inline void append_earfcn(struct bitvec *bv, const struct osmo_earfcn_si2q *e, size_t *e_offset, uint8_t budget)
{
bool appended;
unsigned int old = bv->cur_bit; /* save current position to make rollback possible */
int rem = ((int)budget) - 40;
if (rem <= 0)
return;
OSMO_ASSERT(budget <= SI2Q_MAX_LEN);
/* Additions in Rel-5: */
bitvec_set_bit(bv, H);
/* No 3G Additional Measurement Param. Descr. */
bitvec_set_bit(bv, 0);
/* No 3G ADDITIONAL MEASUREMENT Param. Descr. 2 */
bitvec_set_bit(bv, 0);
/* Additions in Rel-6: */
bitvec_set_bit(bv, H);
/* 3G_CCN_ACTIVE */
bitvec_set_bit(bv, 0);
/* Additions in Rel-7: */
bitvec_set_bit(bv, H);
/* No 700_REPORTING_OFFSET */
bitvec_set_bit(bv, 0);
/* No 810_REPORTING_OFFSET */
bitvec_set_bit(bv, 0);
/* Additions in Rel-8: */
bitvec_set_bit(bv, H);
/* Priority and E-UTRAN Parameters Description */
bitvec_set_bit(bv, 1);
/* budget: 10 bits used above */
/* Serving Cell Priority Parameters Descr. is Present,
* see also: 3GPP TS 44.018, Table 10.5.2.33b.1 */
bitvec_set_bit(bv, 1);
/* GERAN_PRIORITY */
bitvec_set_uint(bv, 0, 3);
/* THRESH_Priority_Search */
bitvec_set_uint(bv, 0, 4);
/* THRESH_GSM_low */
bitvec_set_uint(bv, 0, 4);
/* H_PRIO */
bitvec_set_uint(bv, 0, 2);
/* T_Reselection */
bitvec_set_uint(bv, 0, 2);
/* budget: 26 bits used above */
/* No 3G Priority Parameters Description */
bitvec_set_bit(bv, 0);
/* E-UTRAN Parameters Description */
bitvec_set_bit(bv, 1);
/* E-UTRAN_CCN_ACTIVE */
bitvec_set_bit(bv, 0);
/* E-UTRAN_Start: 9.1.54 */
bitvec_set_bit(bv, 1);
/* E-UTRAN_Stop: 9.1.54 */
bitvec_set_bit(bv, 1);
/* No E-UTRAN Measurement Parameters Descr. */
bitvec_set_bit(bv, 0);
/* No GPRS E-UTRAN Measurement Param. Descr. */
bitvec_set_bit(bv, 0);
/* Note: each of next 3 "repeated" structures might be repeated any
(0, 1, 2...) times - we only support 1 and 0 */
/* Repeated E-UTRAN Neighbour Cells */
bitvec_set_bit(bv, 1);
/* budget: 34 bits used above */
appended = append_eutran_neib_cell(bv, e, e_offset, rem);
if (!appended) { /* appending is impossible within current budget: rollback */
bv->cur_bit = old;
return;
}
/* budget: further 6 bits used below, totalling 40 bits */
/* stop bit - end of Repeated E-UTRAN Neighbour Cells sequence: */
bitvec_set_bit(bv, 0);
/* Note: following 2 repeated structs are not supported ATM */
/* stop bit - end of Repeated E-UTRAN Not Allowed Cells sequence: */
bitvec_set_bit(bv, 0);
/* stop bit - end of Repeated E-UTRAN PCID to TA mapping sequence: */
bitvec_set_bit(bv, 0);
/* Priority and E-UTRAN Parameters Description ends here */
/* No 3G CSG Description */
bitvec_set_bit(bv, 0);
/* No E-UTRAN CSG Description */
bitvec_set_bit(bv, 0);
/* No Additions in Rel-9: */
bitvec_set_bit(bv, L);
}
static int range_encode(enum osmo_gsm48_range r, int *arfcns, int arfcns_used, int *w,
int f0, uint8_t *chan_list)
{
/*
* Manipulate the ARFCN list according to the rules in J4 depending
* on the selected range.
*/
int rc, f0_included;
osmo_gsm48_range_enc_filter_arfcns(arfcns, arfcns_used, f0, &f0_included);
rc = osmo_gsm48_range_enc_arfcns(r, arfcns, arfcns_used, w, 0);
if (rc < 0)
return rc;
/* Select the range and the amount of bits needed */
switch (r) {
case OSMO_GSM48_ARFCN_RANGE_128:
return osmo_gsm48_range_enc_128(chan_list, f0, w);
case OSMO_GSM48_ARFCN_RANGE_256:
return osmo_gsm48_range_enc_256(chan_list, f0, w);
case OSMO_GSM48_ARFCN_RANGE_512:
return osmo_gsm48_range_enc_512(chan_list, f0, w);
case OSMO_GSM48_ARFCN_RANGE_1024:
return osmo_gsm48_range_enc_1024(chan_list, f0, f0_included, w);
default:
return -ERANGE;
};
return f0_included;
}
static inline int f0_helper(int *sc, size_t length, uint8_t *chan_list)
{
int w[OSMO_GSM48_RANGE_ENC_MAX_ARFCNS] = { 0 };
return range_encode(OSMO_GSM48_ARFCN_RANGE_1024, sc, length, w, 0, chan_list);
}
/* Return p(n) for given NR_OF_TDD_CELLS - see Table 9.1.54.1a, 3GPP TS 44.018 */
static unsigned range1024_p(unsigned n)
{
switch (n) {
case 0: return 0;
case 1: return 10;
case 2: return 19;
case 3: return 28;
case 4: return 36;
case 5: return 44;
case 6: return 52;
case 7: return 60;
case 8: return 67;
case 9: return 74;
case 10: return 81;
case 11: return 88;
case 12: return 95;
case 13: return 102;
case 14: return 109;
case 15: return 116;
case 16: return 122;
default: return 0;
}
}
/* Estimate how many bits it'll take to append single FDD UARFCN */
static inline int append_utran_fdd_length(uint16_t u, const int *sc, size_t sc_len, size_t length)
{
uint8_t chan_list[16] = { 0 };
int tmp[sc_len], f0;
memcpy(tmp, sc, sizeof(tmp));
f0 = f0_helper(tmp, length, chan_list);
if (f0 < 0)
return f0;
return 21 + range1024_p(length);
}
/* Append single FDD UARFCN */
static inline int append_utran_fdd(struct bitvec *bv, uint16_t u, int *sc, size_t length)
{
uint8_t chan_list[16] = { 0 };
int f0 = f0_helper(sc, length, chan_list);
if (f0 < 0)
return f0;
/* Repeated UTRAN FDD Neighbour Cells */
bitvec_set_bit(bv, 1);
/* FDD-ARFCN */
bitvec_set_bit(bv, 0);
bitvec_set_uint(bv, u, 14);
/* FDD_Indic0: parameter value '0000000000' is a member of the set? */
bitvec_set_bit(bv, f0);
/* NR_OF_FDD_CELLS */
bitvec_set_uint(bv, length, 5);
f0 = bv->cur_bit;
bitvec_add_range1024(bv, (struct gsm48_range_1024 *)chan_list);
bv->cur_bit = f0 + range1024_p(length);
return 21 + range1024_p(length);
}
static inline int try_adding_uarfcn(struct bitvec *bv, uint16_t *scramble_list,
size_t uarfcn_length, size_t *u_offset,
uint16_t uarfcn, uint8_t num_sc, uint8_t start_pos, uint8_t budget)
{
int i, k, rc, a[uarfcn_length];
if (budget < 23)
return -ENOMEM;
/* copy corresponding Scrambling Codes: range encoder make in-place modifications */
for (i = start_pos, k = 0; i < num_sc; a[k++] = scramble_list[i++]);
/* estimate bit length requirements */
rc = append_utran_fdd_length(uarfcn, a, uarfcn_length, k);
if (rc < 0)
return rc; /* range encoder failure */
if (budget - rc <= 0)
return -ENOMEM; /* we have ran out of budget in current SI2q */
/* compute next offset */
*u_offset += k;
return budget - append_utran_fdd(bv, uarfcn, a, k);
}
/* Append multiple FDD UARFCNs */
static inline void append_uarfcns(struct bitvec *bv, const uint16_t *uarfcn_list, size_t *u_offset,
size_t uarfcn_length, uint16_t *scramble_list, uint8_t budget)
{
int i, rem = budget - 7, st = *u_offset; /* account for constant bits right away */
uint16_t cu = uarfcn_list[*u_offset]; /* caller ensures that length is positive */
OSMO_ASSERT(budget <= SI2Q_MAX_LEN);
if (budget <= 7)
return;
/* 3G Neighbour Cell Description */
bitvec_set_bit(bv, 1);
/* No Index_Start_3G */
bitvec_set_bit(bv, 0);
/* No Absolute_Index_Start_EMR */
bitvec_set_bit(bv, 0);
/* UTRAN FDD Description */
bitvec_set_bit(bv, 1);
/* No Bandwidth_FDD */
bitvec_set_bit(bv, 0);
for (i = *u_offset; i <= uarfcn_length; i++)
if (uarfcn_list[i] != cu) { /* we've reached new UARFCN */
rem = try_adding_uarfcn(bv, scramble_list, uarfcn_length, u_offset, cu, i, st, rem);
if (rem < 0)
break;
if (i < uarfcn_length) {
cu = uarfcn_list[i];
st = i;
} else {
break;
}
}
/* stop bit - end of Repeated UTRAN FDD Neighbour Cells */
bitvec_set_bit(bv, 0);
/* UTRAN TDD Description */
bitvec_set_bit(bv, 0);
}
static size_t si2q_earfcn_count(const struct osmo_earfcn_si2q *e)
{
unsigned i, ret = 0;
if (!e)
return 0;
for (i = 0; i < e->length; i++)
if (e->arfcn[i] != OSMO_EARFCN_INVALID)
ret++;
return ret;
}
/* generate SI2quater rest octets: 3GPP TS 44.018 § 10.5.2.33b */
int osmo_gsm48_rest_octets_si2quater_encode(uint8_t *data, uint8_t si2q_index, uint8_t si2q_count,
const uint16_t *uarfcn_list, size_t *u_offset,
size_t uarfcn_length, uint16_t *scramble_list,
struct osmo_earfcn_si2q *si2quater_neigh_list,
size_t *e_offset)
{
int rc;
struct bitvec bv;
if (si2q_count < si2q_index)
return -EINVAL;
bv.data = data;
bv.data_len = 20;
bitvec_zero(&bv);
/* BA_IND: Set to '0' as that's what we use for SI2xxx type,
* whereas '1' is used for SI5xxx type messages. The point here
* is to be able to correlate whether a given MS measurement
* report was using the neighbor cells advertised in SI2 or in
* SI5, as those two could very well be different */
bitvec_set_bit(&bv, 0);
/* 3G_BA_IND */
bitvec_set_bit(&bv, 1);
/* MP_CHANGE_MARK */
bitvec_set_bit(&bv, 0);
/* SI2quater_INDEX */
bitvec_set_uint(&bv, si2q_index, 4);
/* SI2quater_COUNT */
bitvec_set_uint(&bv, si2q_count, 4);
/* No Measurement_Parameters Description */
bitvec_set_bit(&bv, 0);
/* No GPRS_Real Time Difference Description */
bitvec_set_bit(&bv, 0);
/* No GPRS_BSIC Description */
bitvec_set_bit(&bv, 0);
/* No GPRS_REPORT PRIORITY Description */
bitvec_set_bit(&bv, 0);
/* No GPRS_MEASUREMENT_Parameters Description */
bitvec_set_bit(&bv, 0);
/* No NC Measurement Parameters */
bitvec_set_bit(&bv, 0);
/* No extension (length) */
bitvec_set_bit(&bv, 0);
rc = SI2Q_MAX_LEN - (bv.cur_bit + 3);
if (rc > 0 && uarfcn_length - *u_offset > 0)
append_uarfcns(&bv, uarfcn_list, u_offset, uarfcn_length, scramble_list, rc);
else /* No 3G Neighbour Cell Description */
bitvec_set_bit(&bv, 0);
/* No 3G Measurement Parameters Description */
bitvec_set_bit(&bv, 0);
/* No GPRS_3G_MEASUREMENT Parameters Descr. */
bitvec_set_bit(&bv, 0);
rc = SI2Q_MAX_LEN - bv.cur_bit;
if (rc > 0 && si2q_earfcn_count(si2quater_neigh_list) - *e_offset > 0)
append_earfcn(&bv, si2quater_neigh_list, e_offset, rc);
else /* No Additions in Rel-5: */
bitvec_set_bit(&bv, L);
bitvec_spare_padding(&bv, (bv.data_len * 8) - 1);
return bv.data_len;
}
/* Append selection parameters to bitvec */
static void append_selection_params(struct bitvec *bv,
const struct osmo_gsm48_si_selection_params *sp)
{
if (sp->present) {
bitvec_set_bit(bv, H);
bitvec_set_bit(bv, sp->cbq);
bitvec_set_uint(bv, sp->cell_resel_off, 6);
bitvec_set_uint(bv, sp->temp_offs, 3);
bitvec_set_uint(bv, sp->penalty_time, 5);
} else {
bitvec_set_bit(bv, L);
}
}
/* Append power offset to bitvec */
static void append_power_offset(struct bitvec *bv,
const struct osmo_gsm48_si_power_offset *po)
{
if (po->present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, po->power_offset, 2);
} else {
bitvec_set_bit(bv, L);
}
}
/* Append GPRS indicator to bitvec */
static void append_gprs_ind(struct bitvec *bv,
const struct osmo_gsm48_si3_gprs_ind *gi)
{
if (gi->present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, gi->ra_colour, 3);
/* 0 == SI13 in BCCH Norm, 1 == SI13 sent on BCCH Ext */
bitvec_set_bit(bv, gi->si13_position);
} else {
bitvec_set_bit(bv, L);
}
}
/* Generate SI3 Rest Octests (Chapter 10.5.2.34 / Table 10.4.72) */
int osmo_gsm48_rest_octets_si3_encode(uint8_t *data, const struct osmo_gsm48_si_ro_info *si3)
{
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = data;
bv.data_len = 4;
/* Optional Selection Parameters */
append_selection_params(&bv, &si3->selection_params);
/* Optional Power Offset */
append_power_offset(&bv, &si3->power_offset);
/* Do we have a SI2ter on the BCCH? */
if (si3->si2ter_indicator)
bitvec_set_bit(&bv, H);
else
bitvec_set_bit(&bv, L);
/* Early Classmark Sending Control */
if (si3->early_cm_ctrl)
bitvec_set_bit(&bv, H);
else
bitvec_set_bit(&bv, L);
/* Do we have a SI Type 9 on the BCCH? */
if (si3->scheduling.present) {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, si3->scheduling.where, 3);
} else {
bitvec_set_bit(&bv, L);
}
/* GPRS Indicator */
append_gprs_ind(&bv, &si3->gprs_ind);
/* 3G Early Classmark Sending Restriction. If H, then controlled by
* early_cm_ctrl above */
if (si3->early_cm_restrict_3g)
bitvec_set_bit(&bv, L);
else
bitvec_set_bit(&bv, H);
if (si3->si2quater_indicator) {
bitvec_set_bit(&bv, H); /* indicator struct present */
bitvec_set_uint(&bv, 0, 1); /* message is sent on BCCH Norm */
}
bitvec_spare_padding(&bv, (bv.data_len*8)-1);
return bv.data_len;
}
static int append_lsa_params(struct bitvec *bv,
const struct osmo_gsm48_lsa_params *lsa_params)
{
/* FIXME */
return -1;
}
/* Generate SI4 Rest Octets (Chapter 10.5.2.35) */
int osmo_gsm48_rest_octets_si4_encode(uint8_t *data, const struct osmo_gsm48_si_ro_info *si4, int len)
{
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = data;
bv.data_len = len;
/* SI4 Rest Octets O */
append_selection_params(&bv, &si4->selection_params);
append_power_offset(&bv, &si4->power_offset);
append_gprs_ind(&bv, &si4->gprs_ind);
if (0 /* FIXME */) {
/* H and SI4 Rest Octets S */
bitvec_set_bit(&bv, H);
/* LSA Parameters */
if (si4->lsa_params.present) {
bitvec_set_bit(&bv, H);
append_lsa_params(&bv, &si4->lsa_params);
} else {
bitvec_set_bit(&bv, L);
}
/* Cell Identity */
if (1) {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, si4->cell_id, 16);
} else {
bitvec_set_bit(&bv, L);
}
/* LSA ID Information */
if (0) {
bitvec_set_bit(&bv, H);
/* FIXME */
} else {
bitvec_set_bit(&bv, L);
}
} else {
/* L and break indicator */
bitvec_set_bit(&bv, L);
bitvec_set_bit(&bv, si4->break_ind ? H : L);
}
return bv.data_len;
}
/* GSM 04.18 ETSI TS 101 503 V8.27.0 (2006-05)
<SI6 rest octets> ::=
{L | H <PCH and NCH info>}
{L | H <VBS/VGCS options : bit(2)>}
{ < DTM_support : bit == L > I < DTM_support : bit == H >
< RAC : bit (8) >
< MAX_LAPDm : bit (3) > }
< Band indicator >
{ L | H < GPRS_MS_TXPWR_MAX_CCH : bit (5) > }
<implicit spare >;
*/
int osmo_gsm48_rest_octets_si6_encode(uint8_t *data, const struct osmo_gsm48_si6_ro_info *in)
{
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = data;
bv.data_len = 1;
if (in->pch_nch_info.present) {
bitvec_set_bit(&bv, H);
bitvec_set_bit(&bv, !!in->pch_nch_info.paging_channel_restructuring);
bitvec_set_uint(&bv, in->pch_nch_info.nln_sacch, 2);
if (in->pch_nch_info.call_priority_present) {
bitvec_set_bit(&bv, 1);
bitvec_set_uint(&bv, in->pch_nch_info.call_priority, 3);
} else {
bitvec_set_bit(&bv, 0);
}
bitvec_set_bit(&bv, !!in->pch_nch_info.nln_status_sacch);
} else {
bitvec_set_bit(&bv, L);
}
if (in->vbs_vgcs_options.present) {
bitvec_set_bit(&bv, H);
bitvec_set_bit(&bv, !!in->vbs_vgcs_options.inband_notifications);
bitvec_set_bit(&bv, !!in->vbs_vgcs_options.inband_pagings);
} else {
bitvec_set_bit(&bv, L);
}
if (in->dtm_support.present) {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, in->dtm_support.rac, 8);
bitvec_set_uint(&bv, in->dtm_support.max_lapdm, 3);
} else {
bitvec_set_bit(&bv, L);
}
if (in->band_indicator_1900)
bitvec_set_bit(&bv, H);
else
bitvec_set_bit(&bv, L);
if (in->gprs_ms_txpwr_max_ccch.present) {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, in->gprs_ms_txpwr_max_ccch.max_txpwr, 5);
} else {
bitvec_set_bit(&bv, L);
}
bitvec_spare_padding(&bv, (bv.data_len * 8) - 1);
return bv.data_len;
}
static unsigned int decode_t3192(unsigned int t3192)
{
/* See also 3GPP TS 44.060
Table 12.24.2: GPRS Cell Options information element details */
static const unsigned int decode_t3192_tbl[8] = {500, 1000, 1500, 0, 80, 120, 160, 200};
OSMO_ASSERT(t3192 <= 7);
return decode_t3192_tbl[t3192];
}
static unsigned int decode_drx_timer(unsigned int drx)
{
static const unsigned int decode_drx_timer_tbl[8] = {0, 1, 2, 4, 8, 16, 32, 64};
OSMO_ASSERT(drx <= 7);
return decode_drx_timer_tbl[drx];
}
static int decode_gprs_cell_opt(struct osmo_gprs_cell_options *gco, struct bitvec *bv)
{
gco->nmo = bitvec_get_uint(bv, 2);
gco->t3168 = (bitvec_get_uint(bv, 3) + 1) * 500;
gco->t3192 = decode_t3192(bitvec_get_uint(bv, 3));
gco->drx_timer_max = decode_drx_timer(bitvec_get_uint(bv, 3));
/* ACCESS_BURST_TYPE: */
bitvec_get_uint(bv, 1);
/* CONTROL_ACK_TYPE: */
gco->ctrl_ack_type_use_block = bitvec_get_uint(bv, 1);
gco->bs_cv_max = bitvec_get_uint(bv, 4);
if (bitvec_get_uint(bv, 1)) {
bitvec_get_uint(bv, 3); /* DEC */
bitvec_get_uint(bv, 3); /* INC */
bitvec_get_uint(bv, 3); /* MAX */
}
if (bitvec_get_uint(bv, 1)) {
int ext_len = bitvec_get_uint(bv, 6);
if (ext_len < 0)
return ext_len;
unsigned int cur_bit = bv->cur_bit;
/* Extension Information */
/* R99 extension: */
gco->ext_info.egprs_supported = bitvec_get_uint(bv, 1);
if (gco->ext_info.egprs_supported) {
gco->ext_info.use_egprs_p_ch_req = !bitvec_get_uint(bv, 1);
gco->ext_info.bep_period = bitvec_get_uint(bv, 4);
}
gco->ext_info.pfc_supported = bitvec_get_uint(bv, 1);
gco->ext_info.dtm_supported = bitvec_get_uint(bv, 1);
gco->ext_info.bss_paging_coordination = bitvec_get_uint(bv, 1);
/* REL-4 extension: */
gco->ext_info.ccn_active = bitvec_get_uint(bv, 1);
bitvec_get_uint(bv, 1); /* NW_EXT_UTBF */
bv->cur_bit = cur_bit + ext_len + 1;
}
return 0;
}
static void decode_gprs_pwr_ctrl_pars(struct osmo_gprs_power_ctrl_pars *pcp, struct bitvec *bv)
{
pcp->alpha = bitvec_get_uint(bv, 4);
pcp->t_avg_w = bitvec_get_uint(bv,5);
pcp->t_avg_t = bitvec_get_uint(bv, 5);
pcp->pc_meas_chan = bitvec_get_uint(bv, 1);
pcp->n_avg_i = bitvec_get_uint(bv, 4);
}
/*! Decode SI13 Rest Octests (04.08 Chapter 10.5.2.37b).
* \param[out] si13 decoded SI13 rest octets
* \param[in] encoded SI13 rest octets
* \returns parsed bits on success, negative on error */
int osmo_gsm48_rest_octets_si13_decode(struct osmo_gsm48_si13_info *si13, const uint8_t *data)
{
struct osmo_gprs_cell_options *co = &si13->cell_opts;
struct osmo_gprs_power_ctrl_pars *pcp = &si13->pwr_ctrl_pars;
struct bitvec bv;
int rc;
memset(&bv, 0, sizeof(bv));
bv.data = (uint8_t *) data;
bv.data_len = 20;
memset(si13, 0, sizeof(*si13));
if (bitvec_get_bit_high(&bv) == H) {
si13->bcch_change_mark = bitvec_get_uint(&bv, 3);
si13->si_change_field = bitvec_get_uint(&bv, 4);
if (bitvec_get_uint(&bv, 1)) {
si13->bcch_change_mark = bitvec_get_uint(&bv, 2);
/* FIXME: implement parsing GPRS Mobile Allocation IE */
return -ENOTSUP;
}
if (bitvec_get_uint(&bv, 1)) {
/* PBCCH present in cell */
/* FIXME: parse not implemented */
return -ENOTSUP;
} else {
/* PBCCH not present in cell */
si13->rac = bitvec_get_uint(&bv, 8);
si13->spgc_ccch_sup = bitvec_get_uint(&bv, 1);
si13->prio_acc_thr = bitvec_get_uint(&bv, 3);
si13->net_ctrl_ord = bitvec_get_uint(&bv, 2);
if ((rc = decode_gprs_cell_opt(co, &bv)) < 0)
return rc;
decode_gprs_pwr_ctrl_pars(pcp, &bv);
}
}
return bv.cur_bit;
}
/* GPRS Mobile Allocation as per TS 04.60 Chapter 12.10a:
< GPRS Mobile Allocation IE > ::=
< HSN : bit (6) >
{ 0 | 1 < RFL number list : < RFL number list struct > > }
{ 0 < MA_LENGTH : bit (6) >
< MA_BITMAP: bit (val(MA_LENGTH) + 1) >
| 1 { 0 | 1 <ARFCN index list : < ARFCN index list struct > > } } ;
< RFL number list struct > :: =
< RFL_NUMBER : bit (4) >
{ 0 | 1 < RFL number list struct > } ;
< ARFCN index list struct > ::=
< ARFCN_INDEX : bit(6) >
{ 0 | 1 < ARFCN index list struct > } ;
*/
static int append_gprs_mobile_alloc(struct bitvec *bv)
{
/* Hopping Sequence Number */
bitvec_set_uint(bv, 0, 6);
if (0) {
/* We want to use a RFL number list */
bitvec_set_bit(bv, 1);
/* FIXME: RFL number list */
} else {
bitvec_set_bit(bv, 0);
}
if (0) {
/* We want to use a MA_BITMAP */
bitvec_set_bit(bv, 0);
/* FIXME: MA_LENGTH, MA_BITMAP, ... */
} else {
bitvec_set_bit(bv, 1);
if (0) {
/* We want to provide an ARFCN index list */
bitvec_set_bit(bv, 1);
/* FIXME */
} else {
bitvec_set_bit(bv, 0);
}
}
return 0;
}
static int encode_t3192(unsigned int t3192)
{
/* See also 3GPP TS 44.060
Table 12.24.2: GPRS Cell Options information element details */
if (t3192 == 0)
return 3;
else if (t3192 <= 80)
return 4;
else if (t3192 <= 120)
return 5;
else if (t3192 <= 160)
return 6;
else if (t3192 <= 200)
return 7;
else if (t3192 <= 500)
return 0;
else if (t3192 <= 1000)
return 1;
else if (t3192 <= 1500)
return 2;
else
return -EINVAL;
}
static int encode_drx_timer(unsigned int drx)
{
if (drx == 0)
return 0;
else if (drx == 1)
return 1;
else if (drx == 2)
return 2;
else if (drx <= 4)
return 3;
else if (drx <= 8)
return 4;
else if (drx <= 16)
return 5;
else if (drx <= 32)
return 6;
else if (drx <= 64)
return 7;
else
return -EINVAL;
}
/* GPRS Cell Options as per TS 04.60 Chapter 12.24
< GPRS Cell Options IE > ::=
< NMO : bit(2) >
< T3168 : bit(3) >
< T3192 : bit(3) >
< DRX_TIMER_MAX: bit(3) >
< ACCESS_BURST_TYPE: bit >
< CONTROL_ACK_TYPE : bit >
< BS_CV_MAX: bit(4) >
{ 0 | 1 < PAN_DEC : bit(3) >
< PAN_INC : bit(3) >
< PAN_MAX : bit(3) >
{ 0 | 1 < Extension Length : bit(6) >
< bit (val(Extension Length) + 1
& { < Extension Information > ! { bit ** = <no string> } } ;
< Extension Information > ::=
{ 0 | 1 < EGPRS_PACKET_CHANNEL_REQUEST : bit >
< BEP_PERIOD : bit(4) > }
< PFC_FEATURE_MODE : bit >
< DTM_SUPPORT : bit >
<BSS_PAGING_COORDINATION: bit >
<spare bit > ** ;
*/
static int append_gprs_cell_opt(struct bitvec *bv,
const struct osmo_gprs_cell_options *gco)
{
int t3192, drx_timer_max;
t3192 = encode_t3192(gco->t3192);
if (t3192 < 0)
return t3192;
drx_timer_max = encode_drx_timer(gco->drx_timer_max);
if (drx_timer_max < 0)
return drx_timer_max;
bitvec_set_uint(bv, gco->nmo, 2);
/* See also 3GPP TS 44.060
Table 12.24.2: GPRS Cell Options information element details */
bitvec_set_uint(bv, gco->t3168 / 500 - 1, 3);
bitvec_set_uint(bv, t3192, 3);
bitvec_set_uint(bv, drx_timer_max, 3);
/* ACCESS_BURST_TYPE: Hard-code 8bit */
bitvec_set_bit(bv, 0);
/* CONTROL_ACK_TYPE: */
bitvec_set_bit(bv, gco->ctrl_ack_type_use_block);
bitvec_set_uint(bv, gco->bs_cv_max, 4);
if (0) {
/* hard-code no PAN_{DEC,INC,MAX} */
bitvec_set_bit(bv, 0);
} else {
/* copied from ip.access BSC protocol trace */
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, 1, 3); /* DEC */
bitvec_set_uint(bv, 1, 3); /* INC */
bitvec_set_uint(bv, 15, 3); /* MAX */
}
if (!gco->ext_info_present) {
/* no extension information */
bitvec_set_bit(bv, 0);
} else {
/* extension information */
bitvec_set_bit(bv, 1);
/* R99 extension: */
if (!gco->ext_info.egprs_supported) {
/* 6bit length of extension */
bitvec_set_uint(bv, (1 + 5)-1, 6);
/* EGPRS supported in the cell */
bitvec_set_bit(bv, 0);
} else {
/* 6bit length of extension */
bitvec_set_uint(bv, (1 + 5 + 5)-1, 6);
/* EGPRS supported in the cell */
bitvec_set_bit(bv, 1);
/* 1bit EGPRS PACKET CHANNEL REQUEST (inverted logic) */
bitvec_set_bit(bv, !gco->ext_info.use_egprs_p_ch_req);
/* 4bit BEP PERIOD */
bitvec_set_uint(bv, gco->ext_info.bep_period, 4);
}
bitvec_set_bit(bv, gco->ext_info.pfc_supported);
bitvec_set_bit(bv, gco->ext_info.dtm_supported);
bitvec_set_bit(bv, gco->ext_info.bss_paging_coordination);
/* REL-4 extension: */
bitvec_set_bit(bv, gco->ext_info.ccn_active);
bitvec_set_bit(bv, 0); /* NW_EXT_UTBF disabled */
}
return 0;
}
static void append_gprs_pwr_ctrl_pars(struct bitvec *bv,
const struct osmo_gprs_power_ctrl_pars *pcp)
{
bitvec_set_uint(bv, pcp->alpha, 4);
bitvec_set_uint(bv, pcp->t_avg_w, 5);
bitvec_set_uint(bv, pcp->t_avg_t, 5);
bitvec_set_uint(bv, pcp->pc_meas_chan, 1);
bitvec_set_uint(bv, pcp->n_avg_i, 4);
}
/* Generate SI13 Rest Octests (04.08 Chapter 10.5.2.37b) */
int osmo_gsm48_rest_octets_si13_encode(uint8_t *data, const struct osmo_gsm48_si13_info *si13)
{
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = data;
bv.data_len = 20;
if (0) {
/* No rest octets */
bitvec_set_bit(&bv, L);
} else {
bitvec_set_bit(&bv, H);
bitvec_set_uint(&bv, si13->bcch_change_mark, 3);
bitvec_set_uint(&bv, si13->si_change_field, 4);
if (1) {
bitvec_set_bit(&bv, 0);
} else {
bitvec_set_bit(&bv, 1);
bitvec_set_uint(&bv, si13->bcch_change_mark, 2);
append_gprs_mobile_alloc(&bv);
}
/* PBCCH not present in cell:
it shall never be indicated according to 3GPP TS 44.018 Table 10.5.2.37b.1 */
bitvec_set_bit(&bv, 0);
bitvec_set_uint(&bv, si13->rac, 8);
bitvec_set_bit(&bv, si13->spgc_ccch_sup);
bitvec_set_uint(&bv, si13->prio_acc_thr, 3);
bitvec_set_uint(&bv, si13->net_ctrl_ord, 2);
append_gprs_cell_opt(&bv, &si13->cell_opts);
append_gprs_pwr_ctrl_pars(&bv, &si13->pwr_ctrl_pars);
/* 3GPP TS 44.018 Release 6 / 10.5.2.37b */
bitvec_set_bit(&bv, H); /* added Release 99 */
/* claim our SGSN is compatible with Release 99, as EDGE and EGPRS
* was only added in this Release */
bitvec_set_bit(&bv, 1);
}
bitvec_spare_padding(&bv, (bv.data_len*8)-1);
return bv.data_len;
}
/***********************************************************************
* Decoder
***********************************************************************/
/*! Decode SI3 Rest Octests (Chapter 10.5.2.34 / Table 10.4.72).
* \param[out] si3 decoded SI3 rest octets
* \param[in] encoded SI3 rest octets, 4 octets long */
void osmo_gsm48_rest_octets_si3_decode(struct osmo_gsm48_si_ro_info *si3, const uint8_t *data)
{
struct osmo_gsm48_si_selection_params *sp = &si3->selection_params;
struct osmo_gsm48_si_power_offset *po = &si3->power_offset;
struct osmo_gsm48_si3_gprs_ind *gi = &si3->gprs_ind;
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = (uint8_t *) data;
bv.data_len = 4;
memset(si3, 0, sizeof(*si3));
/* Optional Selection Parameters */
if (bitvec_get_bit_high(&bv) == H) {
sp->present = 1;
sp->cbq = bitvec_get_uint(&bv, 1);
sp->cell_resel_off = bitvec_get_uint(&bv, 6);
sp->temp_offs = bitvec_get_uint(&bv, 3);
sp->penalty_time = bitvec_get_uint(&bv, 5);
} else {
sp->present = 0;
}
/* Optional Power Offset */
if (bitvec_get_bit_high(&bv) == H) {
po->present = 1;
po->power_offset = bitvec_get_uint(&bv, 2);
} else {
po->present = 0;
}
/* System Information 2ter Indicator */
if (bitvec_get_bit_high(&bv) == H)
si3->si2ter_indicator = 1;
else
si3->si2ter_indicator = 0;
/* Early Classmark Sending Control */
if (bitvec_get_bit_high(&bv) == H)
si3->early_cm_ctrl = 1;
else
si3->early_cm_ctrl = 0;
/* Scheduling if and where */
if (bitvec_get_bit_high(&bv) == H) {
si3->scheduling.present = 1;
si3->scheduling.where = bitvec_get_uint(&bv, 3);
} else {
si3->scheduling.present = 0;
}
/* GPRS Indicator */
if (bitvec_get_bit_high(&bv) == H) {
gi->present = 1;
gi->ra_colour = bitvec_get_uint(&bv, 3);
gi->si13_position = bitvec_get_uint(&bv, 1);
} else {
gi->present = 0;
}
/* 3G Early Classmark Sending Restriction. If H, then controlled by
* early_cm_ctrl above */
if (bitvec_get_bit_high(&bv) == H)
si3->early_cm_restrict_3g = 0;
else
si3->early_cm_restrict_3g = 1;
if (bitvec_get_bit_high(&bv) == H)
si3->si2quater_indicator = 1;
else
si3->si2quater_indicator = 0;
}
void osmo_gsm48_rest_octets_si4_decode(struct osmo_gsm48_si_ro_info *si4, const uint8_t *data, int len)
{
struct osmo_gsm48_si_selection_params *sp = &si4->selection_params;
struct osmo_gsm48_si_power_offset *po = &si4->power_offset;
struct osmo_gsm48_si3_gprs_ind *gi = &si4->gprs_ind;
struct bitvec bv;
memset(&bv, 0, sizeof(bv));
bv.data = (uint8_t *) data;
bv.data_len = len;
memset(si4, 0, sizeof(*si4));
/* Optional Selection Parameters */
if (bitvec_get_bit_high(&bv) == H) {
sp->present = 1;
sp->cbq = bitvec_get_uint(&bv, 1);
sp->cell_resel_off = bitvec_get_uint(&bv, 6);
sp->temp_offs = bitvec_get_uint(&bv, 3);
sp->penalty_time = bitvec_get_uint(&bv, 5);
} else {
sp->present = 0;
}
/* Optional Power Offset */
if (bitvec_get_bit_high(&bv) == H) {
po->present = 1;
po->power_offset = bitvec_get_uint(&bv, 2);
} else {
po->present = 0;
}
/* GPRS Indicator */
if (bitvec_get_bit_high(&bv) == H) {
gi->present = 1;
gi->ra_colour = bitvec_get_uint(&bv, 3);
gi->si13_position = bitvec_get_uint(&bv, 1);
} else {
gi->present = 0;
}
}
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