diff --git a/library/LAPDm_RAW_PT.ttcn b/library/LAPDm_RAW_PT.ttcn
index fe2d321..222c1aa 100644
--- a/library/LAPDm_RAW_PT.ttcn
+++ b/library/LAPDm_RAW_PT.ttcn
@@ -36,6 +36,17 @@
 		charstring err optional
 	}
 
+	/* directly switch to a dedicated channel (without RACH/IMM.ASS */
+	type record DCCH_switch_req {
+		Arfcn arfcn,
+		RslChannelNr chan_nr,
+		GsmTsc tsc
+	}
+
+	type record DCCH_switch_res {
+		charstring err optional
+	}
+
 	type record length(8) of uint8_t TfiList;
 	type record TbfPars {
 		GsmArfcn	arfcn optional,
@@ -104,12 +115,14 @@
 	type port LAPDm_SP_PT message {
 		in	BCCH_tune_req,
 			DCCH_establish_req,
+			DCCH_switch_req,
 			DCCH_release_req,
 			TBF_UL_establish_req,
 			TBF_DL_establish_req,
 			RLCMAC_ph_data_req,
 			LAPDm_ph_data;
 		out	DCCH_establish_res,
+			DCCH_switch_res,
 			TBF_UL_establish_res,
 			RLCMAC_ph_data_ind,
 			LAPDm_ph_data;
@@ -118,11 +131,13 @@
 	/* port from user (external) point of view */
 	type port LAPDm_PT message {
 		in	DCCH_establish_res,
+			DCCH_switch_res,
 			TBF_UL_establish_res,
 			RLCMAC_ph_data_ind,
 			LAPDm_ph_data;
 		out	BCCH_tune_req,
 			DCCH_establish_req,
+			DCCH_switch_req,
 			DCCH_release_req,
 			TBF_UL_establish_req,
 			TBF_DL_establish_req,
@@ -222,6 +237,15 @@
 		set_ph_state(PH_STATE_DCH);
 	}
 
+	/* switching directly to a dedicated channel *without RACH/IMM-ASS */
+	private function f_switch_dcch(Arfcn arfcn, RslChannelNr chan_nr, GsmTsc tsc) runs on lapdm_CT {
+		set_ph_state(PH_STATE_TUNING_DCH);
+		/* store/save channel description */
+		chan_desc.chan_nr := chan_nr;
+		f_L1CTL_DM_EST_REQ(L1CTL,arfcn, chan_nr, tsc);
+		set_ph_state(PH_STATE_DCH);
+	}
+
 	/* initialize a tfi_usf array with "not used" value 255 for all TN */
 	function f_TfiUsfArrInit() return TfiUsfArr {
 		var TfiUsfArr tua := { 255, 255, 255, 255, 255, 255, 255, 255 };
@@ -374,6 +398,7 @@
 		var RLCMAC_ph_data_ind rpdi;
 		var RLCMAC_ph_data_req rpdr;
 		var DCCH_establish_req est_req;
+		var DCCH_switch_req sw_req;
 		var DCCH_establish_res est_res;
 
 		f_init_tbf();
@@ -422,6 +447,17 @@
 				}
 				LAPDM_SP.send(res);
 			}
+			[] LAPDM_SP.receive(DCCH_switch_req:?) -> value sw_req {
+				var DCCH_switch_res res;
+				f_switch_dcch(sw_req.arfcn, sw_req.chan_nr, sw_req.tsc);
+				if (ph_state == PH_STATE_DCH) {
+					res := { omit };
+				} else {
+					res := { "Unable to switch to DCCH" };
+				}
+				LAPDM_SP.send(res);
+			}
+
 
 			[] as_tbf_ul_est();
 			[] as_tbf_dl_est();