BTS_Tests.ttcn: introduce TC_pcu_data_ind_lqual_cbHEADmaster

The idea of this test case is to verify that the link quality
measurements, in particular C/I (Carrier-to-Interference ratio),
are delivered to the PCU (as a part of PCUIF_DATA.ind).

The C/I ratio needs to be calculated by the transceiver from the
training sequence of each burst, where we can compare the "ideal"
training sequence with the actual training sequence and then
express that in cB (centiBels).

This test case can only be executed with fake_trx.py and trxcon,
because this pair allows us to simulate C/I values. Also, the
new TRXD header format needs to be supported (see OS#4006).

Change-Id: I67d89b2f0e13a7a6f74f001b19d37add77ec06f5
Depends: (OsmocomBB) I7080effbbc1022d1884c6d6f0cb580eba8e514ff
Related: OS#1855

1 files changed, 77 insertions, 0 deletions

diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 6972806..ebe74c0 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -422,6 +422,8 @@ function f_init() runs on test_CT {
 		/* Start with a default moderate timing offset equalling TA=2, and RSSI=-60 */
 		ret := f_TRXC_transceive(BTS_TRXC, g_bts_trxc_conn_id, valueof(ts_TRXC_FAKE_TIMING(2*256)));
 		ret := f_TRXC_transceive(BTS_TRXC, g_bts_trxc_conn_id, valueof(ts_TRXC_FAKE_RSSI(-60)));
+		/* FIXME: OsmoBTS may have different AB / NB threshold (see MIN_QUAL_NORM, MIN_QUAL_RACH) */
+		ret := f_TRXC_transceive(BTS_TRXC, g_bts_trxc_conn_id, valueof(ts_TRXC_FAKE_CI(0)));
 	}
 
 	/* Wait some extra time to make sure the BTS emits a stable carrier.
@@ -4315,6 +4317,80 @@ testcase TC_pcu_ext_rach_content() runs on test_CT {
 	setverdict(pass);
 }
 
+private function f_TC_pcu_data_ind_lqual_cb(int16_t lqual_cb_exp, int16_t thresh)
+runs on test_CT {
+	var template PCUIF_send_data sdt;
+	var PCUIF_send_data sd;
+	var int16_t lqual_cb;
+	timer T := 1.0;
+
+	/* PCUIF_DATA.ind is encapsulated into a supplementary record */
+	sdt := t_SD_PCUIF_MSGT(g_pcu_conn_id, PCU_IF_MSG_DATA_IND);
+
+	/* Send a random PDTCH frame over Um */
+	L1CTL.send(ts_L1CTL_TRAFFIC_REQ(ts_RslChanNr_PDCH(7), ts_RslLinkID_DCCH(0),
+					'0000'O & f_rnd_octstring(21)));
+
+	T.start;
+	alt {
+	/* If expected link quality is above the threshold */
+	[lqual_cb_exp >= thresh] PCU.receive(sdt) -> value sd {
+		lqual_cb := sd.data.u.data_ind.lqual_cb;
+		log("Rx PCUIF_DATA.ind (lqual_cb=", lqual_cb, ")");
+
+		/* Make sure the actual link quality matches the expected value */
+		if (not match(lqual_cb, lqual_cb_exp)) {
+			setverdict(fail, log2str("Link quality ", lqual_cb, " does not match ",
+						 "expected value ", lqual_cb_exp));
+		} else {
+			setverdict(pass);
+		}
+		}
+	/* If expected link quality is below the threshold */
+	[lqual_cb_exp < thresh] PCU.receive(sdt) -> value sd {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail,
+					log2str("Rx unexpected PCUIF_DATA.ind: ", sd.data));
+		}
+	/* Ignore PCUIF_RTS.req and PCUIF_TIME.ind */
+	[] PCU.receive { repeat; }
+	[lqual_cb_exp < thresh] T.timeout {
+		log("Rx nothing, as expected");
+		setverdict(pass);
+		}
+	[lqual_cb_exp >= thresh] T.timeout {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail,
+					"Timeout waiting for PCUIF_DATA.ind");
+		}
+	}
+}
+
+/* Verify C/I (Carrier-to-Interference ratio) processing of PDTCH frames */
+testcase TC_pcu_data_ind_lqual_cb() runs on test_CT {
+	f_init_pcu_test();
+	PCU.clear;
+
+	f_init_l1ctl();
+	f_l1_tune(L1CTL);
+
+	/* Activate a PDCH channel on TS7 */
+	f_TC_pcu_act_req(0, 0, 7, true);
+
+	/* Tune trxcon to that PDCH channel on TS7 */
+	f_L1CTL_DM_EST_REQ(L1CTL, { false, mp_trx0_arfcn },
+			   valueof(ts_RslChanNr_PDCH(7)), 7);
+
+	/* C/I in centiBels, test range: -256 .. +1280, step 128 */
+	for (var int16_t i := -256; i <= 1280; i := i + 128) {
+		var TrxcMessage ret;
+
+		ret := f_TRXC_transceive(BTS_TRXC, g_bts_trxc_conn_id,
+					 valueof(ts_TRXC_FAKE_CI(i)));
+
+		/* FIXME: OsmoBTS may have different threshold (see MIN_QUAL_NORM) */
+		f_TC_pcu_data_ind_lqual_cb(i, thresh := 0);
+	}
+}
+
 /* Send PAGING via RSL, expect it to shw up on PCU socket */
 testcase TC_pcu_paging_from_rsl() runs on test_CT {
 	f_init_pcu_test();
@@ -6163,6 +6239,7 @@ control {
 		execute( TC_pcu_data_req_imm_ass_pch() );
 		execute( TC_pcu_rach_content() );
 		execute( TC_pcu_ext_rach_content() );
+		execute( TC_pcu_data_ind_lqual_cb() );
 		execute( TC_pcu_paging_from_rsl() );
 		execute( TC_pcu_time_ind() );
 		execute( TC_pcu_rts_req() );