diff --git a/GSM/GSMCommon.cpp b/GSM/GSMCommon.cpp
new file mode 100644
index 0000000..87f5ab2
--- /dev/null
+++ b/GSM/GSMCommon.cpp
@@ -0,0 +1,76 @@
+/*
+* Copyright 2008 Free Software Foundation, Inc.
+* Copyright 2011 Range Networks, Inc.
+*
+* This software is distributed under the terms of the GNU Affero Public License.
+* See the COPYING file in the main directory for details.
+*
+* This use of this software may be subject to additional restrictions.
+* See the LEGAL file in the main directory for details.
+
+	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 "GSMCommon.h"
+
+using namespace GSM;
+using namespace std;
+
+
+const BitVector GSM::gTrainingSequence[] = {
+    BitVector("00100101110000100010010111"),
+    BitVector("00101101110111100010110111"),
+    BitVector("01000011101110100100001110"),
+    BitVector("01000111101101000100011110"),
+    BitVector("00011010111001000001101011"),
+    BitVector("01001110101100000100111010"),
+    BitVector("10100111110110001010011111"),
+    BitVector("11101111000100101110111100"),
+};
+
+const BitVector GSM::gDummyBurst("0001111101101110110000010100100111000001001000100000001111100011100010111000101110001010111010010100011001100111001111010011111000100101111101010000");
+
+const BitVector GSM::gRACHSynchSequence("01001011011111111001100110101010001111000");
+
+
+int32_t GSM::FNDelta(int32_t v1, int32_t v2)
+{
+	static const int32_t halfModulus = gHyperframe/2;
+	int32_t delta = v1-v2;
+	if (delta>=halfModulus) delta -= gHyperframe;
+	else if (delta<-halfModulus) delta += gHyperframe;
+	return (int32_t) delta;
+}
+
+int GSM::FNCompare(int32_t v1, int32_t v2)
+{
+	int32_t delta = FNDelta(v1,v2);
+	if (delta>0) return 1;
+	if (delta<0) return -1;
+	return 0;
+}
+
+
+
+
+ostream& GSM::operator<<(ostream& os, const Time& t)
+{
+	os << t.TN() << ":" << t.FN();
+	return os;
+}
+
+
+// vim: ts=4 sw=4