Review at https://gerrit.osmocom.org/6856
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
---
M src/common/measurement.c
1 file changed, 99 insertions(+), 3 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/56/6856/1
diff --git a/src/common/measurement.c b/src/common/measurement.c
index 4e9a534..1406fef 100644
--- a/src/common/measurement.c
+++ b/src/common/measurement.c
@@ -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.
@@ -183,9 +274,6 @@
/* 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",
@@ -200,6 +288,14 @@
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));
--
To view, visit https://gerrit.osmocom.org/6856
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I16eb3747a1c23df935a4c50dafe46abce512a474
Gerrit-PatchSet: 1
Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Owner: Harald Welte <lafo...@gnumonks.org>
