diff --git a/library/GSM_Types.ttcn b/library/GSM_Types.ttcn
index 5884c27..b86bfd7 100644
--- a/library/GSM_Types.ttcn
+++ b/library/GSM_Types.ttcn
@@ -247,5 +247,10 @@
 	return GSM51_MFRAMES_PER_SEC * int2float(bs_ag_blks_res);
 }
 
+/* compute TC as per 45.002 6.3.1.3 */
+function f_gsm_compute_tc(integer fn) return integer {
+	return (fn / 51) mod 8;
+}
+
 
 } with { encode "RAW"; variant "FIELDORDER(msb)" }
diff --git a/library/Osmocom_Types.ttcn b/library/Osmocom_Types.ttcn
index 713acc9..a6d5c82 100644
--- a/library/Osmocom_Types.ttcn
+++ b/library/Osmocom_Types.ttcn
@@ -99,5 +99,24 @@
 	self.stop;
 }
 
+type record of integer IntegerRecord;
+
+function int2bool(integer int) return boolean {
+	if (int != 0) {
+		return true;
+	} else {
+		return false;
+	}
+}
+
+function f_array_contains(IntegerRecord arr, integer key) return boolean {
+	for (var integer i:= 0; i< sizeof(arr); i := i + 1) {
+		if (arr[i] == key) {
+		return true;
+			}
+	}
+	return false;
+}
+
 
 } with { encode "RAW"; variant "FIELDORDER(msb)" }