diff --git a/openbsc/src/libmsc/gsm_04_11_helper.c b/openbsc/src/libmsc/gsm_04_11_helper.c
new file mode 100644
index 0000000..f48c6de
--- /dev/null
+++ b/openbsc/src/libmsc/gsm_04_11_helper.c
@@ -0,0 +1,37 @@
+/* Helpers for SMS/GSM 04.11 */
+/*
+ * (C) 2014 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_04_11.h>
+
+uint8_t sms_next_rp_msg_ref(struct gsm_subscriber_connection *conn)
+{
+	const uint8_t rp_msg_ref = conn->next_rp_ref;
+	/*
+	 * This should wrap as the valid range is 0 to 255. We only
+	 * transfer one SMS at a time so we don't need to check if
+	 * the id has been already assigned.
+	 */
+	conn->next_rp_ref += 1;
+
+	return rp_msg_ref;
+}
+