Update README and add contrib dir

contrib/tsn/model/tsn-transmission-selection-algo.h

@@ -0,0 +1,71 @@
+#ifndef TSN_TRANSMISSION_SELECTION_ALGO_H
+#define TSN_TRANSMISSION_SELECTION_ALGO_H
+
+#include "ns3/object.h"
+#include "ns3/packet.h"
+#include "ns3/nstime.h"
+
+#include "ns3/tsn-net-device.h"
+
+namespace ns3
+{
+
+class TsnNetDevice;
+
+class TsnTransmissionSelectionAlgo: public Object
+{
+  public:
+    /**
+     * \brief Get the TypeId
+     *
+     * \return The TypeId for this class
+     */
+    static TypeId GetTypeId();
+
+    /**
+     * \brief Create a TsnTransmissionSelectionAlgo
+     */
+    TsnTransmissionSelectionAlgo();
+
+    /**
+     * Destroy a TsnTransmissionSelectionAlgo
+     *
+     * This is the destructor for the TsnTransmissionSelectionAlgo.
+     */
+    ~TsnTransmissionSelectionAlgo();
+
+    // Delete copy constructor and assignment operator to avoid misuse
+    TsnTransmissionSelectionAlgo& operator=(const TsnTransmissionSelectionAlgo&) = delete;
+    TsnTransmissionSelectionAlgo(const TsnTransmissionSelectionAlgo&) = delete;
+
+    void SetTsnNetDevice(Ptr<TsnNetDevice> net);
+    void SetQueue(Ptr<Queue<Packet>> queue);
+
+
+    virtual bool IsReadyToTransmit();
+
+    virtual void TransmitStart(Ptr<Packet> p, Time txTime);
+    virtual void TransmitComplete(Ptr<Packet> p);
+
+    virtual void UpdateTransmissionGate(bool IsOpen);
+
+    Time GetHardwareLatency();
+
+  protected:
+    Ptr<TsnNetDevice>  m_net;
+    Ptr<Queue<Packet>> m_queue;
+    bool m_transmissionGateIsOpen;
+    bool m_MultidropMode;
+    Callback<void> ReadyToTransmitCallback;
+
+  private:
+
+    Time m_minLatencyOverhead;
+    Time m_maxLatencyOverhead;
+};
+
+}
+
+
+
+#endif /* TSN_TRANSMISSION_SELECTION_ALGO_H */