diff --git a/bts/BTS_Tests_SMSCB.ttcn b/bts/BTS_Tests_SMSCB.ttcn
index 11855bf..92e8094 100644
--- a/bts/BTS_Tests_SMSCB.ttcn
+++ b/bts/BTS_Tests_SMSCB.ttcn
@@ -243,8 +243,17 @@
 	f_init();
 
 	f_init_l1ctl();
-	f_l1_tune(L1CTL, ccch_mode := CCCH_MODE_COMBINED_CBCH);
-	/* FIXME: switch to dedicated mode for SDCCH/8 */
+
+	/* Tune L1 to the given CBCH timeslot (SDCCH4+CBCH or SDCCH8+CBCH)  */
+	if (match(pars.chan_nr, t_RslChanNr_CBCH4(0))) {
+		f_l1_tune(L1CTL, ccch_mode := CCCH_MODE_COMBINED_CBCH);
+	} else {
+		f_l1_tune(L1CTL, ccch_mode := CCCH_MODE_COMBINED);
+		/* TODO: also handle frequency hopping parameters */
+		L1CTL.send(ts_L1CTL_DM_EST_REQ_H0(pars.chan_nr,
+						  7 /* TODO: mp_tsc */,
+						  mp_trx0_arfcn));
+	}
 
 	/* send SMSCB[s] via RSL */
 	f_smscb_setup_rsl_chan(pars.basic, false);