hodec2: [2/2] implement automatic choice between FULL and SUBSET measurements

Add TDMA_MEAS_SET_AUTO to indicate automatic choice between FULL and
SUBSET measurements depending on DTX. So far use only in hodec2.

TDMA_MEAS_SET_AUTO looks at each individual measurement report's DTX
flag and for each report chooses FULL if DTX is not used, or SUB if DTX
is used.

The default setting for 'handover2 tdma-measurement' is still 'subset'.
To use the automatic choice, users need configure
  handover2 tdma-measurement auto

Change-Id: I67dce55ccf892c8679272ee5dfedc25620f0f725

6 files changed, 33 insertions, 22 deletions

diff --git a/include/osmocom/bsc/handover_cfg.h b/include/osmocom/bsc/handover_cfg.h
index 6e003af94..551ce8df5 100644
--- a/include/osmocom/bsc/handover_cfg.h
+++ b/include/osmocom/bsc/handover_cfg.h
@@ -38,18 +38,6 @@ static inline int bool2i(bool arg)
 	return arg? 1 : 0;
 }
 
-static inline bool a2tdma(const char *arg)
-{
-	if (!strcmp(arg, "full"))
-		return true;
-	return false;
-}
-
-static inline const char *tdma2a(bool val)
-{
-	return val? "full" : "subset";
-}
-
 /* The HO_CFG_ONE_MEMBER macro gets redefined, depending on whether to define struct members,
  * function declarations or definitions... It is of the format
  *   HO_CFG_ONE_MEMBER(TYPE, NAME, DEFAULT_VAL,
@@ -188,10 +176,13 @@ static inline const char *tdma2a(bool val)
 		"Disable in-call assignment\n" \
 		"Enable in-call assignment\n") \
 	\
-	HO_CFG_ONE_MEMBER(bool, hodec2_full_tdma, subset, \
-		"handover2 ", "tdma-measurement", "full|subset", a2tdma, "%s", tdma2a, \
+	HO_CFG_ONE_MEMBER(enum tdma_meas_set, hodec2_tdma_meas_set, subset, \
+		"handover2 ", "tdma-measurement", "auto|full|subset", \
+		tdma_meas_set_from_str, "%s", tdma_meas_set_name, \
 		HO_CFG_STR_HANDOVER2 \
 		"Define measurement set of TDMA frames\n" \
+		"Use full set when DTX is not in use, use subset when DTX is in use," \
+		" as indicated by each Measurement Report\n" \
 		"Full set of 102/104 TDMA frames\n" \
 		"Sub set of 4 TDMA frames (SACCH)\n") \
 	\
diff --git a/include/osmocom/bsc/meas_rep.h b/include/osmocom/bsc/meas_rep.h
index 5cfeb98fb..402a888b1 100644
--- a/include/osmocom/bsc/meas_rep.h
+++ b/include/osmocom/bsc/meas_rep.h
@@ -68,6 +68,12 @@ enum tdma_meas_set {
 	TDMA_MEAS_SET_AUTO,
 };
 
+extern const struct value_string tdma_meas_set_names[];
+static inline const char *tdma_meas_set_name(enum tdma_meas_set val)
+{ return get_value_string(tdma_meas_set_names, val); }
+static inline enum tdma_meas_set tdma_meas_set_from_str(const char *name)
+{ return get_string_value(tdma_meas_set_names, name); }
+
 /* obtain an average over the last 'num' fields in the meas reps */
 int get_meas_rep_avg(const struct gsm_lchan *lchan,
 		     enum tdma_meas_field field, enum tdma_meas_dir dir, enum tdma_meas_set set,
diff --git a/src/osmo-bsc/handover_decision_2.c b/src/osmo-bsc/handover_decision_2.c
index 67208fe90..3fa1084e4 100644
--- a/src/osmo-bsc/handover_decision_2.c
+++ b/src/osmo-bsc/handover_decision_2.c
@@ -244,16 +244,14 @@ static struct gsm_meas_rep_cell *cell_in_rep(struct gsm_meas_rep *mr, uint16_t a
 static int current_rxlev(struct gsm_lchan *lchan)
 {
 	struct gsm_bts *bts = lchan->ts->trx->bts;
-	return get_meas_rep_avg(lchan, TDMA_MEAS_FIELD_RXLEV, TDMA_MEAS_DIR_DL,
-				ho_get_hodec2_full_tdma(bts->ho) ? TDMA_MEAS_SET_FULL : TDMA_MEAS_SET_SUB,
+	return get_meas_rep_avg(lchan, TDMA_MEAS_FIELD_RXLEV, TDMA_MEAS_DIR_DL, ho_get_hodec2_tdma_meas_set(bts->ho),
 				ho_get_hodec2_rxlev_avg_win(bts->ho));
 }
 
 static int current_rxqual(struct gsm_lchan *lchan)
 {
 	struct gsm_bts *bts = lchan->ts->trx->bts;
-	return get_meas_rep_avg(lchan, TDMA_MEAS_FIELD_RXQUAL, TDMA_MEAS_DIR_DL,
-				ho_get_hodec2_full_tdma(bts->ho) ? TDMA_MEAS_SET_FULL : TDMA_MEAS_SET_SUB,
+	return get_meas_rep_avg(lchan, TDMA_MEAS_FIELD_RXQUAL, TDMA_MEAS_DIR_DL, ho_get_hodec2_tdma_meas_set(bts->ho),
 				ho_get_hodec2_rxqual_avg_win(bts->ho));
 }
 
diff --git a/src/osmo-bsc/meas_rep.c b/src/osmo-bsc/meas_rep.c
index 97c30ac1a..776c610df 100644
--- a/src/osmo-bsc/meas_rep.c
+++ b/src/osmo-bsc/meas_rep.c
@@ -81,8 +81,14 @@ unsigned int calc_initial_idx(unsigned int array_size,
 }
 
 static inline enum meas_rep_field choose_meas_rep_field(enum tdma_meas_field field, enum tdma_meas_dir dir,
-							enum tdma_meas_set set)
+							enum tdma_meas_set set, const struct gsm_meas_rep *meas_rep)
 {
+	if (set == TDMA_MEAS_SET_AUTO) {
+		bool dtx_in_use;
+		dtx_in_use = (meas_rep->flags & ((dir == TDMA_MEAS_DIR_UL) ? MEAS_REP_F_UL_DTX : MEAS_REP_F_DL_DTX));
+		set = (dtx_in_use ? TDMA_MEAS_SET_SUB : TDMA_MEAS_SET_FULL);
+	}
+
 	osmo_static_assert(TDMA_MEAS_FIELD_RXLEV >= 0 && TDMA_MEAS_FIELD_RXLEV <= 1
 			   && TDMA_MEAS_FIELD_RXQUAL >= 0 && TDMA_MEAS_FIELD_RXQUAL <= 1
 			   && TDMA_MEAS_DIR_UL >= 0 && TDMA_MEAS_DIR_UL <= 1
@@ -139,7 +145,7 @@ int get_meas_rep_avg(const struct gsm_lchan *lchan,
 		enum meas_rep_field use_field;
 		int val;
 
-		use_field = choose_meas_rep_field(field, dir, set);
+		use_field = choose_meas_rep_field(field, dir, set, &lchan->meas_rep[j]);
 		val = get_field(&lchan->meas_rep[j], use_field);
 
 		if (val >= 0) {
@@ -170,7 +176,7 @@ int meas_rep_n_out_of_m_be(const struct gsm_lchan *lchan,
 		enum meas_rep_field use_field;
 		int val;
 
-		use_field = choose_meas_rep_field(field, dir, set);
+		use_field = choose_meas_rep_field(field, dir, set, &lchan->meas_rep[j]);
 		val = get_field(&lchan->meas_rep[j], use_field);
 
 		if (val >= be) /* implies that val < 0 will not count */
@@ -182,3 +188,10 @@ int meas_rep_n_out_of_m_be(const struct gsm_lchan *lchan,
 
 	return 0;
 }
+
+const struct value_string tdma_meas_set_names[] = {
+	{ TDMA_MEAS_SET_FULL, "full" },
+	{ TDMA_MEAS_SET_SUB, "subset" },
+	{ TDMA_MEAS_SET_AUTO, "auto" },
+	{}
+};
diff --git a/tests/bsc/Makefile.am b/tests/bsc/Makefile.am
index a0bbb81b2..2f6677878 100644
--- a/tests/bsc/Makefile.am
+++ b/tests/bsc/Makefile.am
@@ -46,6 +46,7 @@ bsc_test_LDADD = \
 	$(top_builddir)/src/osmo-bsc/gsm_data.o \
 	$(top_builddir)/src/osmo-bsc/handover_cfg.o \
 	$(top_builddir)/src/osmo-bsc/handover_logic.o \
+	$(top_builddir)/src/osmo-bsc/meas_rep.o \
 	$(top_builddir)/src/osmo-bsc/neighbor_ident.o \
 	$(top_builddir)/src/osmo-bsc/net_init.o \
 	$(top_builddir)/src/osmo-bsc/nm_common_fsm.o \
diff --git a/tests/handover_cfg.vty b/tests/handover_cfg.vty
index 4bafd7225..ccb1a6b04 100644
--- a/tests/handover_cfg.vty
+++ b/tests/handover_cfg.vty
@@ -178,7 +178,7 @@ OsmoBSC(config-net)# list
   handover2 power budget hysteresis (<0-999>|default)
   handover2 maximum distance (<0-9999>|default)
   handover2 assignment (0|1|default)
-  handover2 tdma-measurement (full|subset|default)
+  handover2 tdma-measurement (auto|full|subset|default)
   handover2 min rxlev (<-110--50>|default)
   handover2 min rxqual (<0-7>|default)
   handover2 afs-bias rxlev (<0-20>|default)
@@ -335,6 +335,7 @@ OsmoBSC(config-net)# handover2 assignment ?
   default  Use default (0), remove explicit setting on this node
 
 OsmoBSC(config-net)# handover2 tdma-measurement ?
+  auto     Use full set when DTX is not in use, use subset when DTX is in use, as indicated by each Measurement Report
   full     Full set of 102/104 TDMA frames
   subset   Sub set of 4 TDMA frames (SACCH)
   default  Use default (subset), remove explicit setting on this node
@@ -553,6 +554,7 @@ OsmoBSC(config-net-bts)# handover2 assignment ?
   default  Use default (0), remove explicit setting on this node
 
 OsmoBSC(config-net-bts)# handover2 tdma-measurement ?
+  auto     Use full set when DTX is not in use, use subset when DTX is in use, as indicated by each Measurement Report
   full     Full set of 102/104 TDMA frames
   subset   Sub set of 4 TDMA frames (SACCH)
   default  Use default (subset), remove explicit setting on this node