MS Power Control Loop: Support set up of C/I parameters for osmo-bts

This commit extends existing VTY and RSL infrastructure to configure and
manage MS Power Parameters used in MS Power Control loop, by adding
support to set up Carrier-to-Interference (CI) parameters.

Using C/I instead of existing RxQual is preferred due to extended
granularity of C/I (bigger range than RxQual's 0-7).
Furthermore, existing literature (such as "GSM/EDGE: Evolution and Performance"
Table 10.3) provides detailed information about expected target values,
even different values for different channel types. Hence, it was decided
to support setting different MS Power Parameters for different channel
types.

These MS Power Parameters are Osmocom specific, ie. supported only by
newish versions of osmo-bts. Older versions of osmo-bts should ignore
the new IEs added just fine. The new IEs containing the MS POwer
Parameters are not send for non osmo-bts BTSs, hence this commit is
secure with regards to running  osmo-bsc against an ip.access BTS such
as nanoBTS.

Related: SYS#4917
Depends: libosmocore.git Change-Id Iffef0611430ad6c90606149c398d80158633bbca
Change-Id: I7e76ec47b323d469f777624b74b08752d1f5584f

1 files changed, 99 insertions, 0 deletions

diff --git a/src/osmo-bsc/bts_osmobts.c b/src/osmo-bsc/bts_osmobts.c
index 9813a265d..5007d2b90 100644
--- a/src/osmo-bsc/bts_osmobts.c
+++ b/src/osmo-bsc/bts_osmobts.c
@@ -44,6 +44,105 @@ extern struct gsm_bts_model bts_model_nanobts;
 
 static struct gsm_bts_model model_osmobts;
 
+static void enc_osmo_meas_proc_params(struct msgb *msg, const struct gsm_power_ctrl_params *mp)
+{
+	struct osmo_preproc_ave_cfg *ave_cfg;
+	uint8_t *ie_len;
+
+	/* No averaging => no Measurement Averaging parameters */
+	if (mp->ci_fr_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE &&
+	    mp->ci_hr_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE &&
+	    mp->ci_amr_fr_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE &&
+	    mp->ci_amr_hr_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE &&
+	    mp->ci_sdcch_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE &&
+	    mp->ci_gprs_meas.algo == GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE)
+		return;
+
+	/* (TLV) Measurement Averaging parameters for RxLev/RxQual */
+	ie_len = msgb_tl_put(msg, RSL_IPAC_EIE_OSMO_MEAS_AVG_CFG);
+
+	ave_cfg = (struct osmo_preproc_ave_cfg *) msgb_put(msg, sizeof(*ave_cfg));
+
+#define ENC_PROC(PARAMS, TO, TYPE) do { \
+	(TO)->TYPE.ave_enabled = (PARAMS)->TYPE##_meas.algo != GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE; \
+	if ((TO)->TYPE.ave_enabled) { \
+		/* H_REQAVE and H_REQT */ \
+		(TO)->TYPE.h_reqave = (PARAMS)->TYPE##_meas.h_reqave & 0x1f; \
+		(TO)->TYPE.h_reqt = (PARAMS)->TYPE##_meas.h_reqt & 0x1f; \
+		/* Averaging method and parameters */ \
+		(TO)->TYPE.ave_method = ((PARAMS)->TYPE##_meas.algo - 1) & 0x07; \
+		switch ((PARAMS)->TYPE##_meas.algo) { \
+		case GSM_PWR_CTRL_MEAS_AVG_ALGO_OSMO_EWMA: \
+			msgb_v_put(msg, (PARAMS)->TYPE##_meas.ewma.alpha); \
+			break; \
+		case GSM_PWR_CTRL_MEAS_AVG_ALGO_WEIGHTED: \
+		case GSM_PWR_CTRL_MEAS_AVG_ALGO_MOD_MEDIAN: \
+			/* FIXME: unknown format */ \
+			break; \
+		case GSM_PWR_CTRL_MEAS_AVG_ALGO_UNWEIGHTED: \
+		case GSM_PWR_CTRL_MEAS_AVG_ALGO_NONE: \
+			/* No parameters here */ \
+			break; \
+		} \
+	} \
+	} while (0)
+	ENC_PROC(mp, ave_cfg, ci_fr);
+	ENC_PROC(mp, ave_cfg, ci_hr);
+	ENC_PROC(mp, ave_cfg, ci_amr_fr);
+	ENC_PROC(mp, ave_cfg, ci_amr_hr);
+	ENC_PROC(mp, ave_cfg, ci_sdcch);
+	ENC_PROC(mp, ave_cfg, ci_gprs);
+#undef ENC_PROC
+
+	/* Update length part of the containing IE */
+	*ie_len = msg->tail - (ie_len + 1);
+}
+
+/* Appends Osmocom specific extension IEs into RSL_IE_MS_POWER_PARAM */
+void osmobts_enc_power_params_osmo_ext(struct msgb *msg, const struct gsm_power_ctrl_params *cp)
+{
+	struct osmo_preproc_pc_thresh *osmo_thresh;
+	struct osmo_preproc_pc_comp *osmo_thresh_comp;
+	uint8_t *ie_len;
+
+	/* (TLV) Measurement Averaging Configure (C/I) */
+	enc_osmo_meas_proc_params(msg, cp);
+
+	/* (TLV) Thresholds (C/I) */
+	ie_len = msgb_tl_put(msg, RSL_IPAC_EIE_OSMO_MS_PWR_CTL);
+	osmo_thresh = (struct osmo_preproc_pc_thresh *) msgb_put(msg, sizeof(*osmo_thresh));
+	#define ENC_THRESH_CI(TYPE) \
+		osmo_thresh->l_##TYPE = cp->TYPE##_meas.lower_thresh; \
+		osmo_thresh->u_##TYPE = cp->TYPE##_meas.upper_thresh
+	ENC_THRESH_CI(ci_fr);
+	ENC_THRESH_CI(ci_hr);
+	ENC_THRESH_CI(ci_amr_fr);
+	ENC_THRESH_CI(ci_amr_hr);
+	ENC_THRESH_CI(ci_sdcch);
+	ENC_THRESH_CI(ci_gprs);
+	#undef ENC_THRESH_CI
+	/* Update length part of the containing IE */
+	*ie_len = msg->tail - (ie_len + 1);
+
+	/* (TLV) PC Threshold Comparators (C/I) */
+	ie_len = msgb_tl_put(msg, RSL_IPAC_EIE_OSMO_PC_THRESH_COMP);
+	osmo_thresh_comp = (struct osmo_preproc_pc_comp *) msgb_put(msg, sizeof(*osmo_thresh_comp));
+	#define ENC_THRESH_CI(TYPE) \
+		osmo_thresh_comp->TYPE.lower_p = cp->TYPE##_meas.lower_cmp_p & 0x1f; \
+		osmo_thresh_comp->TYPE.lower_n = cp->TYPE##_meas.lower_cmp_n & 0x1f; \
+		osmo_thresh_comp->TYPE.upper_p = cp->TYPE##_meas.upper_cmp_p & 0x1f; \
+		osmo_thresh_comp->TYPE.upper_n = cp->TYPE##_meas.upper_cmp_n & 0x1f
+	ENC_THRESH_CI(ci_fr);
+	ENC_THRESH_CI(ci_hr);
+	ENC_THRESH_CI(ci_amr_fr);
+	ENC_THRESH_CI(ci_amr_hr);
+	ENC_THRESH_CI(ci_sdcch);
+	ENC_THRESH_CI(ci_gprs);
+	#undef ENC_THRESH_CI
+	/* Update length part of the containing IE */
+	*ie_len = msg->tail - (ie_len + 1);
+}
+
 static int power_ctrl_set_c0_power_red(const struct gsm_bts *bts,
 				       const uint8_t red)
 {