diff --git a/src/luop.h b/src/luop.h
new file mode 100644
index 0000000..7e2fbb0
--- /dev/null
+++ b/src/luop.h
@@ -0,0 +1,80 @@
+/* OsmoHLR TX/RX lu operations */
+
+/* (C) 2017 sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Harald Welte <laforge@gnumonks.org>
+ *
+ * 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/>.
+ *
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+#include <osmocom/core/timer.h>
+#include <osmocom/gsm/gsup.h>
+
+#include "db.h"
+
+#define CANCEL_TIMEOUT_SECS	30
+#define ISD_TIMEOUT_SECS	30
+
+enum lu_state {
+	LU_S_NULL,
+	LU_S_LU_RECEIVED,
+	LU_S_CANCEL_SENT,
+	LU_S_CANCEL_ACK_RECEIVED,
+	LU_S_ISD_SENT,
+	LU_S_ISD_ACK_RECEIVED,
+	LU_S_COMPLETE,
+};
+
+extern const struct value_string lu_state_names[];
+
+struct lu_operation {
+	/*! entry in global list of location update operations */
+	struct llist_head list;
+	/*! to which gsup_server do we belong */
+	struct osmo_gsup_server *gsup_server;
+	/*! state of the location update */
+	enum lu_state state;
+	/*! CS (false) or PS (true) Location Update? */
+	bool is_ps;
+	/*! currently running timer */
+	struct osmo_timer_list timer;
+
+	/*! subscriber related to this operation */
+	struct hlr_subscriber subscr;
+	/*! peer VLR/SGSN starting the request */
+	uint8_t *peer;
+};
+
+int osmo_gsup_addr_send(struct osmo_gsup_server *gs,
+			const uint8_t *addr, size_t addrlen,
+			struct msgb *msg);
+
+struct lu_operation *lu_op_alloc(struct osmo_gsup_server *srv);
+struct lu_operation *lu_op_alloc_conn(struct osmo_gsup_conn *conn);
+void lu_op_statechg(struct lu_operation *luop, enum lu_state new_state);
+bool lu_op_fill_subscr(struct lu_operation *luop, struct db_context *dbc,
+		       const char *imsi);
+struct lu_operation *lu_op_by_imsi(const char *imsi,
+				   const struct llist_head *lst);
+
+void lu_op_tx_error(struct lu_operation *luop, enum gsm48_gmm_cause cause);
+void lu_op_tx_ack(struct lu_operation *luop);
+void lu_op_tx_cancel_old(struct lu_operation *luop);
+void lu_op_tx_insert_subscr_data(struct lu_operation *luop);