diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 7912ff6..0eba242 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -1783,6 +1783,55 @@
 	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }
 
+/* establish DChan, verify that the BTS sets the TA in the first SACCH L1 header. 
+TA for the IMM ASS messages is still controlled by g_pars.l1_pars.ms_actual_ta! */
+function f_tc_rsl_chan_initial_ta(charstring id) runs on ConnHdlr {
+	var L1ctlDlMessage l1_dl;
+	var uint5_t ta_to_test := 16;
+
+
+	f_l1_tune(L1CTL);
+	RSL.clear;
+
+	/* tell fake_trx to use a given timing offset for all bursts */
+	f_trx_fake_toffs256(ta_to_test*256);
+
+	f_est_dchan(more_ies :={valueof(t_RSL_IE(RSL_IE_TIMING_ADVANCE, RSL_IE_Body:{timing_adv := ta_to_test}))} );
+
+
+	alt {
+
+	/* Pick all SACCH blocks for checking */
+	[] L1CTL.receive(tr_L1CTL_DATA_IND(g_chan_nr, tr_RslLinkID_SACCH(?))) -> value l1_dl {
+
+		/* The second byte of the L1 header contains the TA. */
+		if (not (l1_dl.payload.data_ind.payload[1] == int2oct(ta_to_test, 1))) {
+			setverdict(fail, "TA in L1 header does not match the signaled (RSL) TA.");
+		}
+
+		}
+
+	/* Ignore all other blocks */
+	[] L1CTL.receive { repeat; }
+
+	}
+
+	f_rsl_chan_deact();
+	f_L1CTL_DM_REL_REQ(L1CTL, g_chan_nr);
+
+	setverdict(pass);
+}
+
+testcase TC_rsl_chan_initial_ta() runs on test_CT {
+	var ConnHdlr vc_conn;
+	var ConnHdlrPars pars;
+	f_init(testcasename());
+	pars := valueof(t_Pars(t_RslChanNr_Bm(1), ts_RSL_ChanMode_SIGN));
+	vc_conn := f_start_handler(refers(f_tc_rsl_chan_initial_ta), pars);
+	vc_conn.done;
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
+}
+
 /* Test if a channel without valid uplink bursts generates RSL CONN FAIL IND (TS 48.058 4.10) */
 private function f_TC_conn_fail_crit(charstring id) runs on ConnHdlr {
 	f_l1_tune(L1CTL);
@@ -4621,6 +4670,7 @@
 	execute( TC_meas_res_sign_sdcch8() );
 	execute( TC_meas_res_sign_tchh_toa256() );
 	execute( TC_rsl_ms_pwr_ctrl() );
+	execute( TC_rsl_chan_initial_ta() );
 	execute( TC_conn_fail_crit() );
 	execute( TC_paging_imsi_80percent() );
 	execute( TC_paging_tmsi_80percent() );