diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 21e5634..5cde0af 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -1,5 +1,26 @@
 module BTS_Tests {
 
+/* Integration Tests for OsmoBTS
+ * (C) 2019-2019 by Harald Welte <laforge@gnumonks.org>
+ * contributions by Vadim Yanitskiy and sysmocom - s.f.m.c. GmbH
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ *
+ * This test suite tests OsmoBTS by attaching to the external interfaces
+ * such as Abis RSL, PCU, VTY as well as by attaching to a MS L1 implementation
+ * using the L1CTL protocol/interface.
+ *
+ * You can run the tests with
+ *  a) osmo-bts-trx + trxcon + fake_trx (without any hardware)
+ *  b) any osmo-bts-* + OsmocomBB layer1 + osmocon (with real BTS hardware)
+ *  c) osmo-bts-virtual + virt_phy (without any hardware)
+ *
+ * Some of the tests will only run on a subset of those three configurations
+ * due to limitations in the respective L1.
+ */
+
 import from Misc_Helpers all;
 import from General_Types all;
 import from GSM_Types all;