diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index e1c64d6..5b69b5d 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -2571,6 +2571,95 @@
 	f_exp_err_rep(RSL_ERR_IE_CONTENT);
 }
 
+/* attempt to activate channel with wrong RSL Message Discriminator IE */
+function f_TC_chan_act_wrong_mdisc(charstring id) runs on ConnHdlr {
+	var template RSL_Message rsl := ts_RSL_CHAN_ACT(g_chan_nr, g_pars.chan_mode);
+	rsl.msg_disc := ts_RSL_MsgDisc(RSL_MDISC_RESERVED, false);
+	RSL.send(rsl);
+	f_rslem_unregister(0, g_chan_nr);
+}
+testcase TC_err_rep_wrong_mdisc() runs on test_CT {
+	var ConnHdlr vc_conn;
+	var ConnHdlrPars pars := valueof(t_Pars(ts_RslChanNr_SDCCH4(0,0), ts_RSL_ChanMode_SIGN));
+
+	f_init(testcasename());
+
+	vc_conn := f_start_handler(refers(f_TC_chan_act_wrong_mdisc), pars);
+	vc_conn.done;
+	f_exp_err_rep(RSL_ERR_MSG_DISCR);
+
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
+}
+
+/* Send messages with wrong message type */
+function f_TC_wrong_msg_type_dchan(charstring id) runs on ConnHdlr {
+	var template (value) RSL_Message rsl_tx;
+	rsl_tx := ts_RSL_CHAN_ACT(g_chan_nr, g_pars.chan_mode);
+	rsl_tx.msg_type := RSL_MT_NOT_CMD;
+	RSL.send(rsl_tx);
+	f_rslem_unregister(0, g_chan_nr);
+}
+function f_TC_wrong_msg_type_rll(charstring id) runs on ConnHdlr {
+	var template (value) RSL_Message rsl_tx;
+	/* we first have to activate the dedicated channel */
+	f_rsl_chan_act(g_pars.chan_mode);
+	/* ... to then send an invalid RLL message */
+	rsl_tx := ts_RSL_UNITDATA_REQ(g_chan_nr, ts_RslLinkID_DCCH(0), '0102'O);
+	rsl_tx.msg_type := RSL_MT_CBCH_LOAD_IND;
+	RSL.send(rsl_tx);
+	f_rslem_unregister(0, g_chan_nr);
+}
+testcase TC_err_rep_wrong_msg_type() runs on test_CT {
+	var ConnHdlr vc_conn;
+	var ConnHdlrPars pars := valueof(t_Pars(ts_RslChanNr_SDCCH4(0,0), ts_RSL_ChanMode_SIGN));
+	var template (value) RSL_Message rsl_tx;
+
+	f_init(testcasename());
+
+	/* Common Channel with wrong message type */
+	RSL_CCHAN.clear;
+	rsl_tx := valueof(ts_RSL_BCCH_INFO(RSL_SYSTEM_INFO_1, ''O));
+	rsl_tx.msg_type := RSL_MT_LOCATION_INFO;
+	RSL_CCHAN.send(ts_RSL_UD(rsl_tx));
+	f_exp_err_rep(RSL_ERR_MSG_TYPE);
+
+	/* TRX Management */
+	RSL_CCHAN.clear;
+	rsl_tx := ts_RSL_SACCH_FILL(RSL_SYSTEM_INFO_5, ''O);
+	rsl_tx.msg_type := RSL_MT_UNIT_DATA_IND;
+	RSL_CCHAN.send(ts_RSL_UD(rsl_tx));
+	f_exp_err_rep(RSL_ERR_MSG_TYPE);
+
+	/* Dedicated Channel */
+	RSL_CCHAN.clear;
+	vc_conn := f_start_handler(refers(f_TC_wrong_msg_type_dchan), pars);
+	vc_conn.done;
+	f_exp_err_rep(RSL_ERR_MSG_TYPE);
+
+	/* RLL */
+	RSL_CCHAN.clear;
+	vc_conn := f_start_handler(refers(f_TC_wrong_msg_type_rll), pars);
+	vc_conn.done;
+	f_exp_err_rep(RSL_ERR_MSG_TYPE);
+}
+
+/* Send messages in wrong sequence (RLL to an inactive lchan) */
+function f_TC_err_rep_wrong_sequence(charstring id) runs on ConnHdlr {
+	RSL.send(ts_RSL_UNITDATA_REQ(g_chan_nr, ts_RslLinkID_DCCH(0), '0102'O));
+	f_rslem_unregister(0, g_chan_nr);
+}
+testcase TC_err_rep_wrong_sequence() runs on test_CT {
+	var ConnHdlr vc_conn;
+	var ConnHdlrPars pars := valueof(t_Pars(ts_RslChanNr_SDCCH4(0,0), ts_RSL_ChanMode_SIGN));
+
+	f_init(testcasename());
+
+	RSL_CCHAN.clear;
+	vc_conn := f_start_handler(refers(f_TC_err_rep_wrong_sequence), pars);
+	vc_conn.done;
+	f_exp_err_rep(RSL_ERR_MSG_SEQ);
+}
+
 /***********************************************************************
  * IPA CRCX/MDCX/DLCS media stream handling
  ***********************************************************************/
@@ -4311,9 +4400,6 @@
 * SMS Broadcast Req / Cmd / CBCH LOad Ind
 * RF resource ind
 * error handling
-** discriminator error
-** type error
-** sequence error
 ** IE duplicated?
 * PCU interface
 ** TIME_IND from BTS->PCU
@@ -4416,6 +4502,10 @@
 	execute( TC_encr_cmd_a52() );
 	execute( TC_encr_cmd_a53() );
 
+	execute( TC_err_rep_wrong_mdisc() );
+	execute( TC_err_rep_wrong_msg_type() );
+	execute( TC_err_rep_wrong_sequence() );
+
 	execute( TC_lapdm_selftest() );
 
 	execute( TC_tch_sign_l2_fill_frame() );