Update README and add contrib dir

contrib/tsn/model/frer-sequence-generation-function.h

@@ -0,0 +1,54 @@
+#ifndef FRER_SEQUENCE_GENERATION_FUNCTION_H
+#define FRER_SEQUENCE_GENERATION_FUNCTION_H
+
+#include "ns3/object.h"
+
+
+namespace ns3
+{
+
+class SequenceGenerationFunction : public Object
+{
+  public:
+    /**
+     * \brief Get the TypeId
+     *
+     * \return The TypeId for this class
+     */
+    static TypeId GetTypeId();
+
+    /**
+     * \brief Create a SequenceGenerationFunction
+     */
+    SequenceGenerationFunction();
+
+    /**
+     * Destroy a SequenceGenerationFunction
+     *
+     * This is the destructor for the SequenceGenerationFunction.
+     */
+    ~SequenceGenerationFunction();
+
+    // Delete copy constructor and assignment operator to avoid misuse
+    SequenceGenerationFunction& operator=(const SequenceGenerationFunction&) = delete;
+    SequenceGenerationFunction(const SequenceGenerationFunction&) = delete;
+
+    void SetStreamHandle(std::vector<uint32_t> frerSeqGenStreamList);
+
+    bool IsApplicable(uint32_t streamHandle);
+    uint16_t GetSequenceNumber();
+
+  protected:
+
+
+  private:
+    std::vector<uint32_t> m_frerSeqGenStreamList;
+    bool m_frerSeqGenDirection;     //out-facing (True) or in-facing (False)
+
+    uint16_t m_GenSeqNum = 0;      //802.1CB-2017 7.4.1.2.2
+
+
+};
+
+}
+#endif /* FRER_SEQUENCE_GENERATION_FUNCTION_H */