l1: Store measurement values sent by the MS

This commit extends the pcu_l1_meas structure by MS side measurement
values which are transmitted by PACKET DOWNLINK ACK/NACK and
PACKET RESOURCE REQUEST messages. The encoded values are remapped to
dB respectively % values. The values are stored in the corresponding
MS object (if there is one).

Note that the values are store as (rounded) integers, so some
different encodings are mapped to the same decoded value.

Sponsored-by: On-Waves ehf

1 files changed, 63 insertions, 1 deletions

diff --git a/src/bts.cpp b/src/bts.cpp
index f94799b6..5fafd84a 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -790,11 +790,62 @@ void gprs_rlcmac_pdch::rcv_control_ack(Packet_Control_Acknowledgement_t *packet,
 		"at no request\n");
 }
 
+static void get_rx_qual_meas(struct pcu_l1_meas *meas, uint8_t rx_qual_enc)
+{
+	static const int16_t rx_qual_map[] = {
+		0, /* 0,14 % */
+		0, /* 0,28 % */
+		1, /* 0,57 % */
+		1, /* 1,13 % */
+		2, /* 2,26 % */
+		5, /* 4,53 % */
+		9, /* 9,05 % */
+		18, /* 18,10 % */
+	};
+
+	meas->set_ms_rx_qual(rx_qual_map[
+		OSMO_MIN(rx_qual_enc, ARRAY_SIZE(rx_qual_map)-1)
+		]);
+}
+
+static void get_meas(struct pcu_l1_meas *meas,
+	const Packet_Resource_Request_t *qr)
+{
+	unsigned i;
+
+	meas->set_ms_c_value(qr->C_VALUE);
+	if (qr->Exist_SIGN_VAR)
+		meas->set_ms_sign_var((qr->SIGN_VAR + 2) / 4); /* SIGN_VAR * 0.25 dB */
+
+	for (i = 0; i < OSMO_MIN(ARRAY_SIZE(qr->Slot), ARRAY_SIZE(meas->ts)); i++)
+	{
+		if (qr->Slot[i].Exist)
+			meas->set_ms_i_level(i, -2 * qr->Slot[i].I_LEVEL);
+	}
+}
+
+static void get_meas(struct pcu_l1_meas *meas,
+	const Channel_Quality_Report_t *qr)
+{
+	unsigned i;
+
+	get_rx_qual_meas(meas, qr->RXQUAL);
+	meas->set_ms_c_value(qr->C_VALUE);
+	meas->set_ms_sign_var((qr->SIGN_VAR + 2) / 4); /* SIGN_VAR * 0.25 dB */
+
+	for (i = 0; i < OSMO_MIN(ARRAY_SIZE(qr->Slot), ARRAY_SIZE(meas->ts)); i++)
+	{
+		if (qr->Slot[i].Exist)
+			meas->set_ms_i_level(i, -2 * qr->Slot[i].I_LEVEL_TN);
+	}
+}
+
 void gprs_rlcmac_pdch::rcv_control_dl_ack_nack(Packet_Downlink_Ack_Nack_t *ack_nack, uint32_t fn)
 {
 	int8_t tfi = 0; /* must be signed */
 	struct gprs_rlcmac_dl_tbf *tbf;
 	int rc;
+	struct pcu_l1_meas meas;
 
 	tfi = ack_nack->DOWNLINK_TFI;
 	tbf = bts()->dl_tbf_by_poll_fn(fn, trx_no(), ts_no);
@@ -841,6 +892,11 @@ void gprs_rlcmac_pdch::rcv_control_dl_ack_nack(Packet_Downlink_Ack_Nack_t *ack_n
 		/* schedule uplink assignment */
 		tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
 	}
+	/* get measurements */
+	if (tbf->ms()) {
+		get_meas(&meas, &ack_nack->Channel_Quality_Report);
+		tbf->ms()->update_l1_meas(&meas);
+	}
 }
 
 void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request, uint32_t fn)
@@ -853,6 +909,7 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 		uint32_t tlli = request->ID.u.TLLI;
 		uint8_t ms_class = 0;
 		uint8_t ta = 0;
+		struct pcu_l1_meas meas;
 
 		GprsMs *ms = bts()->ms_by_tlli(tlli);
 		/* Keep the ms, even if it gets idle temporarily */
@@ -907,6 +964,12 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 		ul_tbf->control_ts = ts_no;
 		/* schedule uplink assignment */
 		ul_tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+
+		/* get measurements */
+		if (ul_tbf->ms()) {
+			get_meas(&meas, request);
+			ul_tbf->ms()->update_l1_meas(&meas);
+		}
 		return;
 	}
 
@@ -933,7 +996,6 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 			"RX: [PCU <- BTS] %s FIXME: Packet resource request\n",
 			tbf_name(ul_tbf));
 	}
-
 }
 
 void gprs_rlcmac_pdch::rcv_measurement_report(Packet_Measurement_Report_t *report, uint32_t fn)