diff --git a/library/GSM_RR_Types.ttcn b/library/GSM_RR_Types.ttcn
index 8cb824d2f..78db7a55b 100644
--- a/library/GSM_RR_Types.ttcn
+++ b/library/GSM_RR_Types.ttcn
@@ -466,6 +466,11 @@ module GSM_RR_Types {
 	} with {
 		variant (pa) "CROSSTAG(spa, pa_disc = '1'B; uldl, pa_disc = '0'B)"
 	};
+	type record TbfStartingTime {
+		uint5_t		t1,
+		uint6_t		t3,
+		uint5_t		t2
+	};
 	type record PacketUlAssignDyn {
 		uint5_t		tfi_assignment,
 		BIT1		polling,
@@ -483,7 +488,7 @@ module GSM_RR_Types {
 		BIT1		ta_index_present,
 		uint4_t		ta_index optional,
 		BIT1		tbf_starting_time_present,
-		uint16_t	tbf_starting_time optional
+		TbfStartingTime	tbf_starting_time optional
 	} with {
 		variant (p0)		"PRESENCE(p0_present = '1'B)"
 		variant (pr_mode)	"PRESENCE(p0_present = '1'B)"
@@ -496,7 +501,7 @@ module GSM_RR_Types {
 		uint4_t		alpha optional,
 		uint5_t		gamma,
 		BIT2		padding ('01'B),
-		uint16_t	tbf_starting_time
+		TbfStartingTime	tbf_starting_time
 		/* TODO: P0 / PR_MODE */
 	} with {
 		variant (alpha)		"PRESENCE(alpha_present = '1'B)"
@@ -526,7 +531,7 @@ module GSM_RR_Types {
 		BIT1		ta_index_present,
 		uint4_t		ta_index optional,
 		BIT1		tbf_starting_time_present,
-		uint16_t	tbf_starting_time optional,
+		TbfStartingTime	tbf_starting_time optional,
 		BIT1		p0_present,
 		uint4_t		p0 optional,
 		BIT1		pr_mode optional
@@ -564,7 +569,7 @@ module GSM_RR_Types {
 		BIT1		ta_index_present,
 		uint4_t		ta_index optional,
 		BIT1		tbf_starting_time_present,
-		uint16_t	tbf_starting_time optional
+		TbfStartingTime	tbf_starting_time optional
 		/* TODO: Additions for Rel-7 */
 	} with {
 		variant (p0)		"PRESENCE(p0_present = '1'B)"
@@ -578,7 +583,7 @@ module GSM_RR_Types {
 		BIT1		alpha_present,
 		uint4_t		alpha optional,
 		uint5_t		gamma,
-		uint16_t	tbf_starting_time,
+		TbfStartingTime	tbf_starting_time,
 		BIT2		nr_radio_blocks_allocated,
 		BIT1		p0_present,
 		uint4_t		p0 optional,