txop.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2005 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 */

#ifndef TXOP_H
#define TXOP_H

#include "ns3/traced-value.h"
#include "mac-low-transmission-parameters.h"
#include "wifi-mac-header.h"

namespace ns3 {

class Packet;
class ChannelAccessManager;
class MacTxMiddle;
class MacLow;
class WifiMode;
class WifiMacQueue;
class WifiMacQueueItem;
class UniformRandomVariable;
class CtrlBAckResponseHeader;
class WifiRemoteStationManager;

class Txop : public Object
{
public:
  friend class DcfListener;
  friend class MacLowTransmissionListener;

  Txop ();
  virtual ~Txop ();

  static TypeId GetTypeId (void);

  typedef Callback <void, const WifiMacHeader&> TxOk;
  typedef Callback <void, const WifiMacHeader&> TxFailed;
  typedef Callback <void, Ptr<const Packet> > TxDropped;

  virtual bool IsQosTxop () const;

  void SetMacLow (const Ptr<MacLow> low);
  void SetChannelAccessManager (const Ptr<ChannelAccessManager> manager);
  virtual void SetWifiRemoteStationManager (const Ptr<WifiRemoteStationManager> remoteManager);
  void SetTxMiddle (const Ptr<MacTxMiddle> txMiddle);

  void SetTxOkCallback (TxOk callback);
  void SetTxFailedCallback (TxFailed callback);
  void SetTxDroppedCallback (TxDropped callback);

  Ptr<MacLow> GetLow (void) const;

  Ptr<WifiMacQueue > GetWifiMacQueue () const;

  void SetMinCw (uint32_t minCw);
  void SetMaxCw (uint32_t maxCw);
  void SetAifsn (uint8_t aifsn);
  void SetTxopLimit (Time txopLimit);
  uint32_t GetMinCw (void) const;
  uint32_t GetMaxCw (void) const;
  uint8_t GetAifsn (void) const;
  Time GetTxopLimit (void) const;

  virtual void NotifyChannelSwitching (void);
  virtual void NotifySleep (void);
  virtual void NotifyOff (void);
  virtual void NotifyWakeUp (void);
  virtual void NotifyOn (void);

  /* Event handlers */
  virtual void Queue (Ptr<const Packet> packet, const WifiMacHeader &hdr);

  void SendCfFrame (WifiMacType frameType, Mac48Address addr);

  /* Event handlers */
  virtual void MissedCts (void);
  virtual void GotAck (void);
  virtual void MissedAck (void);
  void GotCfEnd (void);
  void MissedCfPollResponse (bool expectedCfAck);
  virtual void GotBlockAck (const CtrlBAckResponseHeader *blockAck, Mac48Address recipient, double rxSnr, WifiMode txMode, double dataSnr);
  virtual void MissedBlockAck (uint8_t nMpdus);

  virtual void StartNextFragment (void);
  virtual void Cancel (void);
  virtual void StartNextPacket (void);
  virtual void EndTxNoAck (void);

  virtual Time GetTxopRemaining (void) const;
  virtual void TerminateTxop (void);

  bool CanStartNextPolling (void) const;


  int64_t AssignStreams (int64_t stream);

  virtual bool IsAccessRequested (void) const;

  void StartBackoffNow (uint32_t nSlots);

protected:
  friend class ChannelAccessManager;

  virtual void DoDispose (void);
  virtual void DoInitialize (void);

  /* dcf notifications forwarded here */
  virtual void NotifyAccessRequested (void);
  virtual void NotifyAccessGranted (void);
  virtual void NotifyInternalCollision (void);
  virtual void NotifyCollision (void);

  virtual void RestartAccessIfNeeded (void);
  virtual void StartAccessIfNeeded (void);

  uint32_t GetCw (void) const;
  void ResetCw (void);
  void UpdateFailedCw (void);
  uint32_t GetBackoffSlots (void) const;
  Time GetBackoffStart (void) const;
  void UpdateBackoffSlotsNow (uint32_t nSlots, Time backoffUpdateBound);

  bool NeedRtsRetransmission (Ptr<const Packet> packet, const WifiMacHeader &hdr);
  bool NeedDataRetransmission (Ptr<const Packet> packet, const WifiMacHeader &hdr);
  virtual bool NeedFragmentation (void) const;

  void NextFragment (void);
  virtual Ptr<Packet> GetFragmentPacket (WifiMacHeader *hdr);
  virtual uint32_t GetNextFragmentSize (void) const;
  virtual uint32_t GetFragmentSize (void) const;
  virtual uint32_t GetFragmentOffset (void) const;
  virtual bool IsLastFragment (void) const;
  void TxDroppedPacket (Ptr<const WifiMacQueueItem> item);

  Ptr<ChannelAccessManager> m_channelAccessManager; 
  TxOk m_txOkCallback; 
  TxFailed m_txFailedCallback; 
  TxDropped m_txDroppedCallback; 
  Ptr<WifiMacQueue> m_queue; 
  Ptr<MacTxMiddle> m_txMiddle; 
  Ptr <MacLow> m_low; 
  Ptr<WifiRemoteStationManager> m_stationManager; 
  Ptr<UniformRandomVariable> m_rng; 

  uint32_t m_cwMin;       
  uint32_t m_cwMax;       
  uint32_t m_cw;          
  uint32_t m_backoff;     
  bool m_accessRequested; 
  uint32_t m_backoffSlots; 

  Time m_backoffStart;

  uint8_t m_aifsn;        
  Time m_txopLimit;       

  Ptr<const Packet> m_currentPacket; 
  WifiMacHeader m_currentHdr; 
  MacLowTransmissionParameters m_currentParams; 
  uint8_t m_fragmentNumber; 
  TracedCallback<uint32_t> m_backoffTrace; 
  TracedValue<uint32_t> m_cwTrace;         
};

} //namespace ns3

#endif /* TXOP_H */