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#include <stdint.h>
#include <errno.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmo-bts/gsm_data.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/measurement.h>
/* Measurment reporting period and mapping of SACCH message block for TCHF
* and TCHH chan As per in 3GPP TS 45.008, secton 8.4.1.
*
* Timeslot number (TN) TDMA frame number (FN) modulo 104
* Half rate, Half rate, Reporting SACCH
* Full Rate subch.0 subch.1 period Message block
* 0 0 and 1 0 to 103 12, 38, 64, 90
* 1 0 and 1 13 to 12 25, 51, 77, 103
* 2 2 and 3 26 to 25 38, 64, 90, 12
* 3 2 and 3 39 to 38 51, 77, 103, 25
* 4 4 and 5 52 to 51 64, 90, 12, 38
* 5 4 and 5 65 to 64 77, 103, 25, 51
* 6 6 and 7 78 to 77 90, 12, 38, 64
* 7 6 and 7 91 to 90 103, 25, 51, 77 */
/* measurement period ends at fn % 104 == ? */
static const uint8_t tchf_meas_rep_fn104[] = {
[0] = 103,
[1] = 12,
[2] = 25,
[3] = 38,
[4] = 51,
[5] = 64,
[6] = 77,
[7] = 90,
};
static const uint8_t tchh0_meas_rep_fn104[] = {
[0] = 103,
[1] = 103,
[2] = 25,
[3] = 25,
[4] = 51,
[5] = 51,
[6] = 77,
[7] = 77,
};
static const uint8_t tchh1_meas_rep_fn104[] = {
[0] = 12,
[1] = 12,
[2] = 38,
[3] = 38,
[4] = 64,
[5] = 64,
[6] = 90,
[7] = 90,
};
/* Measurment reporting period for SDCCH8 and SDCCH4 chan
* As per in 3GPP TS 45.008, section 8.4.2.
*
* Logical Chan TDMA frame number
* (FN) modulo 102
*
* SDCCH/8 12 to 11
* SDCCH/4 37 to 36
*/
/* Added interleve offset to Meas period end Fn which
* would reduce the Meas Res msg load at Abis */
static const uint8_t sdcch8_meas_rep_fn102[] = {
[0] = 11 + 7,
[1] = 11 + 11,
[2] = 11 + 15,
[3] = 11 + 19,
[4] = 11 + 23,
[5] = 11 + 27,
[6] = 11 + 31,
[7] = 11 + 35
};
static const uint8_t sdcch4_meas_rep_fn102[] = {
[0] = 36 + 4,
[1] = 36 + 8,
[2] = 36 + 14,
[3] = 36 + 18
};
/* determine if a measurement period ends at the given frame number */
static int is_meas_complete(struct gsm_lchan *lchan, uint32_t fn)
{
unsigned int fn_mod = -1;
const uint8_t *tbl;
int rc = 0;
enum gsm_phys_chan_config pchan = ts_pchan(lchan->ts);
if (lchan->ts->nr >= 8)
return -EINVAL;
if (pchan >= _GSM_PCHAN_MAX)
return -EINVAL;
switch (pchan) {
case GSM_PCHAN_TCH_F:
fn_mod = fn % 104;
if (tchf_meas_rep_fn104[lchan->ts->nr] == fn_mod)
rc = 1;
break;
case GSM_PCHAN_TCH_H:
fn_mod = fn % 104;
if (lchan->nr == 0)
tbl = tchh0_meas_rep_fn104;
else
tbl = tchh1_meas_rep_fn104;
if (tbl[lchan->ts->nr] == fn_mod)
rc = 1;
break;
case GSM_PCHAN_SDCCH8_SACCH8C:
case GSM_PCHAN_SDCCH8_SACCH8C_CBCH:
fn_mod = fn % 102;
if (sdcch8_meas_rep_fn102[lchan->nr] == fn_mod)
rc = 1;
break;
case GSM_PCHAN_CCCH_SDCCH4:
case GSM_PCHAN_CCCH_SDCCH4_CBCH:
fn_mod = fn % 102;
if (sdcch4_meas_rep_fn102[lchan->nr] == fn_mod)
rc = 1;
break;
default:
rc = 0;
break;
}
DEBUGP(DMEAS,
"%s meas period end fn:%u, fn_mod:%i, status:%d, pchan:%s\n",
gsm_lchan_name(lchan), fn, fn_mod, rc, gsm_pchan_name(pchan));
return rc;
}
/* receive a L1 uplink measurement from L1 */
int lchan_new_ul_meas(struct gsm_lchan *lchan, struct bts_ul_meas *ulm)
{
DEBUGP(DMEAS, "%s adding measurement, num_ul_meas=%d\n",
gsm_lchan_name(lchan), lchan->meas.num_ul_meas);
if (lchan->state != LCHAN_S_ACTIVE) {
LOGP(DMEAS, LOGL_NOTICE, "%s measurement during state: %s\n",
gsm_lchan_name(lchan), gsm_lchans_name(lchan->state));
}
if (lchan->meas.num_ul_meas >= ARRAY_SIZE(lchan->meas.uplink)) {
LOGP(DMEAS, LOGL_NOTICE, "%s no space for uplink measurement\n",
gsm_lchan_name(lchan));
return -ENOSPC;
}
memcpy(&lchan->meas.uplink[lchan->meas.num_ul_meas++], ulm,
sizeof(*ulm));
return 0;
}
/* input: BER in steps of .01%, i.e. percent/100 */
static uint8_t ber10k_to_rxqual(uint32_t ber10k)
{
/* Eight levels of Rx quality are defined and are mapped to the
* equivalent BER before channel decoding, as per in 3GPP TS 45.008,
* secton 8.2.4.
*
* RxQual: BER Range:
* RXQUAL_0 BER < 0,2 % Assumed value = 0,14 %
* RXQUAL_1 0,2 % < BER < 0,4 % Assumed value = 0,28 %
* RXQUAL_2 0,4 % < BER < 0,8 % Assumed value = 0,57 %
* RXQUAL_3 0,8 % < BER < 1,6 % Assumed value = 1,13 %
* RXQUAL_4 1,6 % < BER < 3,2 % Assumed value = 2,26 %
* RXQUAL_5 3,2 % < BER < 6,4 % Assumed value = 4,53 %
* RXQUAL_6 6,4 % < BER < 12,8 % Assumed value = 9,05 %
* RXQUAL_7 12,8 % < BER Assumed value = 18,10 % */
if (ber10k < 20)
return 0;
if (ber10k < 40)
return 1;
if (ber10k < 80)
return 2;
if (ber10k < 160)
return 3;
if (ber10k < 320)
return 4;
if (ber10k < 640)
return 5;
if (ber10k < 1280)
return 6;
return 7;
}
/* Update order TA at end of meas period */
static void lchan_meas_update_ordered_TA(struct gsm_lchan *lchan,
int32_t taqb_sum)
{
int32_t ms_timing_offset = 0;
uint8_t l1_info_valid;
l1_info_valid = lchan->meas.flags & LC_UL_M_F_L1_VALID;
if (l1_info_valid) {
DEBUGP(DMEAS,
"%s Update TA TimingOffset_Mean:%d, UL RX TA:%d, DL ordered TA:%d, flags:%d \n",
gsm_lchan_name(lchan), taqb_sum, lchan->meas.l1_info[1],
lchan->rqd_ta, lchan->meas.flags);
ms_timing_offset =
taqb_sum + (lchan->meas.l1_info[1] - lchan->rqd_ta);
if (ms_timing_offset > 0) {
if (lchan->rqd_ta < MEAS_MAX_TIMING_ADVANCE) {
/* MS is moving away from BTS.
* So increment Ordered TA by 1 */
lchan->rqd_ta++;
}
} else if (ms_timing_offset < 0) {
if (lchan->rqd_ta > MEAS_MIN_TIMING_ADVANCE) {
/* MS is moving toward BTS. So decrement
* Ordered TA by 1 */
lchan->rqd_ta--;
}
}
DEBUGP(DMEAS,
"%s New Update TA--> TimingOff_diff:%d, UL RX TA:%d, DL ordered TA:%d \n",
gsm_lchan_name(lchan), ms_timing_offset,
lchan->meas.l1_info[1], lchan->rqd_ta);
}
/* Clear L1 INFO valid flag at Meas period end */
lchan->meas.flags &= ~LC_UL_M_F_L1_VALID;
return;
}
int lchan_meas_check_compute(struct gsm_lchan *lchan, uint32_t fn)
{
struct gsm_meas_rep_unidir *mru;
uint32_t ber_full_sum = 0;
uint32_t irssi_full_sum = 0;
uint32_t ber_sub_sum = 0;
uint32_t irssi_sub_sum = 0;
int32_t taqb_sum = 0;
unsigned int num_meas_sub = 0;
int i;
/* if measurement period is not complete, abort */
if (!is_meas_complete(lchan, fn))
return 0;
/* if there are no measurements, skip computation */
if (lchan->meas.num_ul_meas == 0)
return 0;
/* compute the actual measurements */
/* step 1: add up */
for (i = 0; i < lchan->meas.num_ul_meas; i++) {
struct bts_ul_meas *m = &lchan->meas.uplink[i];
ber_full_sum += m->ber10k;
irssi_full_sum += m->inv_rssi;
taqb_sum += m->ta_offs_qbits;
if (m->is_sub) {
num_meas_sub++;
ber_sub_sum += m->ber10k;
irssi_sub_sum += m->inv_rssi;
}
}
/* step 2: divide */
ber_full_sum = ber_full_sum / lchan->meas.num_ul_meas;
irssi_full_sum = irssi_full_sum / lchan->meas.num_ul_meas;
taqb_sum = taqb_sum / lchan->meas.num_ul_meas;
if (num_meas_sub) {
ber_sub_sum = ber_sub_sum / num_meas_sub;
irssi_sub_sum = irssi_sub_sum / num_meas_sub;
} else {
ber_sub_sum = ber_full_sum;
irssi_sub_sum = irssi_full_sum;
}
DEBUGP(DMEAS, "%s Computed TA(% 4dqb) BER-FULL(%2u.%02u%%), RSSI-FULL(-%3udBm), "
"BER-SUB(%2u.%02u%%), RSSI-SUB(-%3udBm)\n", gsm_lchan_name(lchan),
taqb_sum, ber_full_sum/100,
ber_full_sum%100, irssi_full_sum, ber_sub_sum/100, ber_sub_sum%100,
irssi_sub_sum);
/* Update ordered TA for DL SACCH L1 Header */
lchan_meas_update_ordered_TA(lchan, taqb_sum);
/* store results */
mru = &lchan->meas.ul_res;
mru->full.rx_lev = dbm2rxlev((int)irssi_full_sum * -1);
mru->sub.rx_lev = dbm2rxlev((int)irssi_sub_sum * -1);
mru->full.rx_qual = ber10k_to_rxqual(ber_full_sum);
mru->sub.rx_qual = ber10k_to_rxqual(ber_sub_sum);
DEBUGP(DMEAS, "%s UL MEAS RXLEV_FULL(%u), RXLEV_SUB(%u),"
"RXQUAL_FULL(%u), RXQUAL_SUB(%u), num_meas_sub(%u), num_ul_meas(%u) \n",
gsm_lchan_name(lchan),
mru->full.rx_lev,
mru->sub.rx_lev,
mru->full.rx_qual,
mru->sub.rx_qual, num_meas_sub, lchan->meas.num_ul_meas);
lchan->meas.flags |= LC_UL_M_F_RES_VALID;
lchan->meas.num_ul_meas = 0;
/* send a signal indicating computation is complete */
return 1;
}
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