diff --git a/library/LAPDm_RAW_PT.ttcn b/library/LAPDm_RAW_PT.ttcn
index 394deab..77f0452 100644
--- a/library/LAPDm_RAW_PT.ttcn
+++ b/library/LAPDm_RAW_PT.ttcn
@@ -38,9 +38,8 @@
 
 	/* directly switch to a dedicated channel (without RACH/IMM.ASS */
 	type record DCCH_switch_req {
-		Arfcn arfcn,
-		RslChannelNr chan_nr,
-		GsmTsc tsc
+		ChannelDescription chan_desc,
+		L1ctlMA ma
 	}
 
 	type record DCCH_switch_res {
@@ -236,17 +235,30 @@
 		/* store/save channel description */
 		chan_desc := imm_ass.chan_desc;
 
-		/* send DM_EST_REQ */
+		/* send DM_EST_REQ, TODO: Mobile Allocation */
 		f_L1CTL_DM_EST_REQ_IA(L1CTL, imm_ass);
 		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 {
+	private function f_switch_dcch(in DCCH_switch_req sw_req) runs on lapdm_CT {
 		set_ph_state(PH_STATE_TUNING_DCH);
 		/* store/save channel description */
-		chan_desc.chan_nr := chan_nr;
-		L1CTL.send(ts_L1CTL_DM_EST_REQ_H0(chan_nr, tsc, arfcn.arfcn));
+		chan_desc := sw_req.chan_desc;
+
+		/* tune the L1 to the indicated channel */
+		if (chan_desc.h) {
+			L1CTL.send(ts_L1CTL_DM_EST_REQ_H1(chan_desc.chan_nr,
+							  chan_desc.tsc,
+							  chan_desc.maio_hsn.hsn,
+							  chan_desc.maio_hsn.maio,
+							  sw_req.ma));
+		} else {
+			L1CTL.send(ts_L1CTL_DM_EST_REQ_H0(chan_desc.chan_nr,
+							  chan_desc.tsc,
+							  chan_desc.arfcn));
+		}
+
 		set_ph_state(PH_STATE_DCH);
 	}
 
@@ -431,7 +443,7 @@
 			}
 			[] 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);
+				f_switch_dcch(sw_req);
 				if (ph_state == PH_STATE_DCH) {
 					res := { omit };
 				} else {