diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index f60da24..0506e64 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -245,7 +245,7 @@
 			},
 			cell_sel_par := ts_CellSelPar_default,
 			rach_control := ts_RachCtrl_default,
-			rest_octets := '2B2B2B2B'O
+			rest_octets := '2C2B2B2B'O /* GPRS present */
 		}
 	}
 }
@@ -3983,6 +3983,174 @@
 	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }
 
+/* Ensure that GPRS capability is not advertised before PCU socket conncet */
+private function f_get_si3(L1CTL_PT pt) runs on test_CT return SystemInformationType3 {
+	var L1ctlDlMessage l1_dl;
+	var SystemInformation si;
+	timer T := 5.0;
+	T.start;
+	alt {
+	[] pt.receive(tr_L1CTL_DATA_IND(t_RslChanNr_BCCH(0), ?)) -> value l1_dl {
+		/* somehow dec_SystemInformation will try to decode even non-RR as SI */
+		if (not (l1_dl.payload.data_ind.payload[1] ==  '06'O)) {
+			log("Ignoring non-RR SI ", l1_dl);
+			repeat;
+		}
+		si := dec_SystemInformation(l1_dl.payload.data_ind.payload)
+		if (not ischosen(si.payload.si3)) {
+			repeat;
+		}
+		}
+	[] pt.receive {
+		repeat;
+		}
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for SI3");
+		}
+	}
+	return si.payload.si3;
+}
+
+/* CSN.1 L/H logic: is the bit at the current position using "inverted logic" (true) or not? */
+private function f_bitpos_is_inv(integer idx) return boolean {
+	select (idx mod 8) {
+	case ((2, 4, 6, 7)) { return true; } /* 1-bits of 0x2B */
+	case else { return false; } /* 0-bits of 0x2B */
+	}
+}
+/* determine if the bit at position 'idx' in 'str' is a CSN.1 'H' (true) or 'L' (false) */
+private function f_bit_is_high(bitstring str, integer idx) return boolean {
+	var boolean invert := f_bitpos_is_inv(idx);
+	if (invert) {
+		if (str[idx] == '1'B) {
+			return false;
+		} else {
+			return true;
+		}
+	} else {
+		if (str[idx] == '1'B) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+}
+/* As the TITAN RAW codec cannot expres the CSN.1 L/H concept yet, we have to do this
+   manually.  Let's hope https://www.eclipse.org/forums/index.php/t/1099087/ takes off and
+   we can replace this piece of code soon ... */
+private function f_si3_has_gprs_indicator(OCT4 si3_restoctets) return boolean {
+	var bitstring bits := oct2bit(si3_restoctets);
+	var integer idx := 0;
+
+	if (f_bit_is_high(bits, idx)) {
+		/* skip Optional selection parameters */
+		idx := idx + 16;
+	} else {
+		idx := idx + 1;
+	}
+
+	if (f_bit_is_high(bits, idx)) {
+		/* skip Optional power offset */
+		idx := idx + 3;
+	} else {
+		idx := idx + 1;
+	}
+
+	/* skip SI2ter Indicator */
+	idx := idx + 1;
+
+	/* skip Early CM Sending Control */
+	idx := idx + 1;
+
+	/* skip Scheduling if and where */
+	if (f_bit_is_high(bits, idx)) {
+		idx := idx + 4;
+	} else {
+		idx := idx + 1;
+	}
+
+	return f_bit_is_high(bits, idx);
+}
+
+testcase TC_pcu_socket_noconnect_nosi3gprs() runs on test_CT {
+	var SystemInformationType3 si3;
+	timer T := 5.0;
+
+	/* don't call f_init() as this would connect PCU socket */
+	f_init_rsl(testcasename());
+	T.start;
+	alt {
+	[] RSL_CCHAN.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_UP});
+	[] T.timeout {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Timeout waiting for ASP_IPA_EVENT_UP");
+		}
+	}
+	f_rsl_bcch_fill(RSL_SYSTEM_INFO_3, ts_SI3_default);
+
+	f_init_l1ctl();
+	f_l1_tune(L1CTL);
+
+	f_sleep(2.0);
+	L1CTL.clear;
+	si3 := f_get_si3(L1CTL);
+	if (f_si3_has_gprs_indicator(si3.rest_octets)) {
+		setverdict(fail, "SI3 indicates GPRS even before PCU socket connected");
+	} else {
+		setverdict(pass);
+	}
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
+}
+
+/* Ensure that GPRS capability is advertised after PCU socket connect */
+testcase TC_pcu_socket_connect_si3gprs() runs on test_CT {
+	var SystemInformationType3 si3;
+
+	/* this (among other things) establishes the first connection to the PCUIF socket */
+	f_init();
+	f_init_l1ctl();
+	f_l1_tune(L1CTL);
+
+	f_sleep(2.0);
+	L1CTL.clear;
+	si3 := f_get_si3(L1CTL);
+	if (not f_si3_has_gprs_indicator(si3.rest_octets)) {
+		setverdict(fail, "SI3 indicates no GPRS despite PCU socket connected");
+	} else {
+		setverdict(pass);
+	}
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
+}
+
+/* Ensure that GPRS capability is no longer advertised after PCU socket disconnect */
+testcase TC_pcu_socket_disconnect_nosi3gprs() runs on test_CT {
+	var SystemInformationType3 si3;
+
+	/* this (among other things) establishes the first connection to the PCUIF socket */
+	f_init();
+	f_init_l1ctl();
+	f_l1_tune(L1CTL);
+
+	f_pcuif_close(PCU, g_pcu_conn_id);
+	g_pcu_conn_id := -1;
+
+	f_sleep(1.0);
+
+	/* re-connect */
+	PCU.clear;
+	f_init_pcu(PCU, testcasename(), g_pcu_conn_id, g_pcu_last_info);
+
+	f_sleep(2.0);
+	L1CTL.clear;
+	si3 := f_get_si3(L1CTL);
+	if (f_si3_has_gprs_indicator(si3.rest_octets)) {
+		setverdict(fail, "SI3 indicates GPRS after PCU socket disconnected");
+	} else {
+		setverdict(pass);
+	}
+
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
+}
+
 
 /***********************************************************************
  * Osmocom Style Dynamic Timeslot Support
@@ -5360,6 +5528,9 @@
 		execute( TC_pcu_rr_suspend() );
 		execute( TC_pcu_socket_connect_multi() );
 		execute( TC_pcu_socket_reconnect() );
+		execute( TC_pcu_socket_noconnect_nosi3gprs() );
+		execute( TC_pcu_socket_connect_si3gprs() );
+		execute( TC_pcu_socket_disconnect_nosi3gprs() );
 	} else {
 		log("PCU socket path not available, skipping PCU tests");
 	}