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measurement: Compute RX{LEV,QUAL}-SUB for SDCCH and non-AMR TCH 

The rules on how to compute RX{LEV,QUAL}-SUB are rather convoluted, and
depend on the detailed channel type and mode.

For SDCCH and TCH/H in signalling mode, it's easy: No DTX is allowed,
and all measurements are used in SUB.

For non-AMR (TCH/F and TCH/H in non-signalling mode), we need to count
the SACCH block measurements, as well as any
SID/SID_UPDATE/L3_FILL/DUMMY blocks received in the blocks of table
8.3 of TS 45.008.

Only AMR (TCH/AFS + TCH/AHS) are more difficult, as there are no fixed
blocks/bursts/frames that always contain uplink messages, but the L1
will have to determine if a valid SID_UPDATE was received or not.

This patch implements the above rules (except AMR related) in the common
part of OsmoBTS.  The AMR specific bits will have to follow as a later
patch, likely in a BTS specific way, i.e. separate changes to
sysmo/lc15/octphy/trx code.

Related: OS#2978
Change-Id: I16eb3747a1c23df935a4c50dafe46abce512a474
This commit is contained in:
Harald Welte 2018-02-23 13:59:17 +01:00
parent 6381900677
commit 3a80a56b9b
1 changed files with 99 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

102
src/common/measurement.c
View File

@ -7,6 +7,97 @@
#include <osmo-bts/gsm_data.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/measurement.h>
#include <osmo-bts/scheduler.h>
/* Tables as per TS 45.008 Section 8.3 */
static const uint8_t ts45008_83_tch_f[] = { 52, 53, 54, 55, 56, 57, 58, 59 };
static const uint8_t ts45008_83_tch_hs0[] = { 0, 2, 4, 6, 52, 54, 56, 58 };
static const uint8_t ts45008_83_tch_hs1[] = { 14, 16, 18, 29, 66, 68, 70, 72 };
/* find out if an array contains a given key as element */
#define ARRAY_CONTAINS(arr, val) array_contains(arr, ARRAY_SIZE(arr), val)
static bool array_contains(const uint8_t *arr, unsigned int len, uint8_t val) {
int i;
for (i = 0; i < len; i++) {
if (arr[i] == val)
return true;
}
return false;
}
/* Decide if a given frame number is part of the "-SUB" measurements (true) or not (false) */
static bool ts45008_83_is_sub(struct gsm_lchan *lchan, uint32_t fn, bool is_amr_sid_update)
{
uint32_t fn104 = fn % 104;
/* See TS 45.008 Sections 8.3 and 8.4 for a detailed descriptions of the rules
* implemented here. We only implement the logic for Voice, not CSD */
switch (lchan->type) {
case GSM_LCHAN_TCH_F:
switch (lchan->tch_mode) {
case GSM48_CMODE_SIGN:
case GSM48_CMODE_SPEECH_V1:
case GSM48_CMODE_SPEECH_EFR:
if (trx_sched_is_sacch_fn(lchan->ts, fn, true))
return true;
if (ARRAY_CONTAINS(ts45008_83_tch_f, fn104))
return true;
break;
case GSM48_CMODE_SPEECH_AMR:
if (trx_sched_is_sacch_fn(lchan->ts, fn, true))
return true;
if (is_amr_sid_update)
return true;
break;
default:
LOGPFN(DMEAS, LOGL_ERROR, fn, "%s: Unsupported lchan->tch_mode %u\n",
gsm_lchan_name(lchan), lchan->tch_mode);
break;
}
break;
case GSM_LCHAN_TCH_H:
switch (lchan->tch_mode) {
case GSM48_CMODE_SPEECH_V1:
if (trx_sched_is_sacch_fn(lchan->ts, fn, true))
return true;
switch (lchan->nr) {
case 0:
if (ARRAY_CONTAINS(ts45008_83_tch_hs0, fn104))
return true;
break;
case 1:
if (ARRAY_CONTAINS(ts45008_83_tch_hs1, fn104))
return true;
break;
default:
OSMO_ASSERT(0);
}
break;
case GSM48_CMODE_SPEECH_AMR:
if (trx_sched_is_sacch_fn(lchan->ts, fn, true))
return true;
if (is_amr_sid_update)
return true;
break;
case GSM48_CMODE_SIGN:
/* No DTX allowed; SUB=FULL, therefore measurements at all frame numbers are
* SUB */
return true;
default:
LOGPFN(DMEAS, LOGL_ERROR, fn, "%s: Unsupported lchan->tch_mode %u\n",
gsm_lchan_name(lchan), lchan->tch_mode);
break;
}
break;
case GSM_LCHAN_SDCCH:
/* No DTX allowed; SUB=FULL, therefore measurements at all frame numbers are SUB */
return true;
default:
break;
}
return false;
}
/* Measurement reporting period and mapping of SACCH message block for TCHF
* and TCHH chan As per in 3GPP TS 45.008, section 8.4.1.
@ -182,9 +273,6 @@ static int is_meas_complete(struct gsm_lchan *lchan, uint32_t fn)
/* receive a L1 uplink measurement from L1 */
int lchan_new_ul_meas(struct gsm_lchan *lchan, struct bts_ul_meas *ulm, uint32_t fn)
{
DEBUGPFN(DMEAS, fn, "%s adding measurement, num_ul_meas=%d\n",
gsm_lchan_name(lchan), lchan->meas.num_ul_meas);
if (lchan->state != LCHAN_S_ACTIVE) {
LOGPFN(DMEAS, LOGL_NOTICE, fn,
"%s measurement during state: %s, num_ul_meas=%d\n",
@ -199,6 +287,14 @@ int lchan_new_ul_meas(struct gsm_lchan *lchan, struct bts_ul_meas *ulm, uint32_t
return -ENOSPC;
}
/* We expect the lower layers to mark AMR SID_UPDATE frames already as such.
* In this function, we only deal with the comon logic as per the TS 45.008 tables */
if (!ulm->is_sub)
ulm->is_sub = ts45008_83_is_sub(lchan, fn, false);
DEBUGPFN(DMEAS, fn, "%s adding measurement (is_sub=%u), num_ul_meas=%d\n",
gsm_lchan_name(lchan), ulm->is_sub, lchan->meas.num_ul_meas);
memcpy(&lchan->meas.uplink[lchan->meas.num_ul_meas++], ulm,
sizeof(*ulm));