diff --git a/ttcn/LibIms_SIPTypesAndValues.ttcn b/ttcn/LibIms_SIPTypesAndValues.ttcn
index bd94c1776b953bbd587136e59f80c09fa81299fb..2b30fd9cfe01b63ced995d43880f29c0ba28400f 100644
--- a/ttcn/LibIms_SIPTypesAndValues.ttcn
+++ b/ttcn/LibIms_SIPTypesAndValues.ttcn
@@ -16,6 +16,10 @@ group Constants
 
 const integer c_ISUP_HOP_COUNT:=31; //TODO replace this value with appropriate PIXIT parameter
 
+// URN scheme (RFC 5031)
+// TODO NOTE: this definition is for temporary use
+const charstring c_urnScheme := "urn";
+
 group UserProfileConstants
 	{
 	  // number of user profile (RESERVED: from 1-10 for SIP profile)
diff --git a/ttcn/LibIms_Steps.ttcn b/ttcn/LibIms_Steps.ttcn
index 9dcc7a33bef0bbee9a39f228bbd07af8b8cd5fdf..c3c372ab2aa9de09597e1faaf183de576b25fe43 100644
--- a/ttcn/LibIms_Steps.ttcn
+++ b/ttcn/LibIms_Steps.ttcn
@@ -807,10 +807,14 @@ module LibIms_Steps
 						p_sipUrl.hostPort := {host := PX_IMS_TS_ISUP_HOME_DOMAIN, portField :=omit}
 				}
 				case (c_serviceProfile_EMERGENCY) {
+						// TODO NOTE: this definition is for temporary use
+				        p_sipUrl.scheme := c_urnScheme;
 						p_sipUrl.userInfo := {userOrTelephoneSubscriber:=PX_IMS_SUT_EMERGENCY_SERVICE, password:=omit};
 						p_sipUrl.hostPort := {host := PX_IMS_SUT_EMERGENCY_HOME_DOMAIN, portField :=omit}
 						}
 				case (c_serviceProfile_EMERGENCY_INVALID) {
+						// TODO NOTE: this definition is for temporary use
+				        p_sipUrl.scheme := c_urnScheme;
 						p_sipUrl.userInfo := {userOrTelephoneSubscriber:=PX_IMS_SUT_EMERGENCY_SERVICE_INVALID, password:=omit};
 						p_sipUrl.hostPort := {host := PX_IMS_SUT_EMERGENCY_HOME_DOMAIN, portField :=omit}
 						}