diff --git a/openair3/NAS/UE/user_defs.h b/openair3/NAS/UE/user_defs.h
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+/*******************************************************************************
+    OpenAirInterface
+    Copyright(c) 1999 - 2014 Eurecom
+
+    OpenAirInterface is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+
+    OpenAirInterface 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenAirInterface.The full GNU General Public License is
+   included in this distribution in the file called "COPYING". If not,
+   see <http://www.gnu.org/licenses/>.
+
+  Contact Information
+  OpenAirInterface Admin: openair_admin@eurecom.fr
+  OpenAirInterface Tech : openair_tech@eurecom.fr
+  OpenAirInterface Dev  : openair4g-devel@lists.eurecom.fr
+
+  Address      : Eurecom, Compus SophiaTech 450, route des chappes, 06451 Biot, France.
+
+ *******************************************************************************/
+/*****************************************************************************
+Source      user_defs.h
+
+Version     0.1
+
+Date        2016/07/01
+
+Product     NAS stack
+
+Subsystem   NAS main process
+
+Author      Frederic Leroy
+
+Description NAS type definition to manage a user equipment
+
+*****************************************************************************/
+#ifndef __USER_DEFS_H__
+#define __USER_DEFS_H__
+
+typedef struct {
+} nas_user_t;
+
+#endif