/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2005,2006 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 ARF_WIFI_MANAGER_H

#define ARF_WIFI_MANAGER_H

#include "wifi-remote-station-manager.h"

namespace ns3 {

/**

 * \brief ARF Rate control algorithm

 *

 * This class implements the so-called ARF algorithm which was

 * initially described in <i>WaveLAN-II: A High-performance wireless 

 * LAN for the unlicensed band</i>, by A. Kamerman and L. Monteban. in

 * Bell Lab Technical Journal, pages 118-133, Summer 1997.

 *

 * This implementation differs from the initial description in that it

 * uses a packet-based timer rather than a time-based timer as described 

 * in XXX (I cannot find back the original paper which described how

 * the time-based timer could be easily replaced with a packet-based 

 * timer.)

 */

class ArfWifiManager : public WifiRemoteStationManager

{

public:

  static TypeId GetTypeId (void);

  ArfWifiManager ();

  virtual ~ArfWifiManager ();

private:

  friend class ArfWifiRemoteStation;

  virtual class WifiRemoteStation *CreateStation (void);

  uint32_t m_timerThreshold;

  uint32_t m_successThreshold;

};

class ArfWifiRemoteStation : public WifiRemoteStation

{

public:

  ArfWifiRemoteStation (Ptr<ArfWifiManager> manager);

  virtual ~ArfWifiRemoteStation ();

protected:

  virtual void DoReportRxOk (double rxSnr, WifiMode txMode);

  virtual void DoReportRtsFailed (void);

  virtual void DoReportDataFailed (void);

  virtual void DoReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr);

  virtual void DoReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr);

  virtual void DoReportFinalRtsFailed (void);

  virtual void DoReportFinalDataFailed (void);

private:

  virtual Ptr<WifiRemoteStationManager> GetManager (void) const;

  virtual WifiMode DoGetDataMode (uint32_t size);

  virtual WifiMode DoGetRtsMode (void);

  uint32_t m_timer;

  uint32_t m_success;

  uint32_t m_failed;

  bool m_recovery;

  uint32_t m_retry;

  uint32_t m_timerTimeout;

  uint32_t m_successThreshold;

  uint32_t m_rate;

  Ptr<ArfWifiManager> m_manager;

private:

  // overriden by AarfMacStation.

  virtual void ReportRecoveryFailure (void);

  virtual void ReportFailure (void);

  uint32_t GetMaxRate (void);

  uint32_t GetMinRate (void);

  bool NeedRecoveryFallback (void);

  bool NeedNormalFallback (void);

protected:

  // called by AarfMacStation.

  uint32_t GetMinTimerTimeout (void);

  uint32_t GetMinSuccessThreshold (void);

  uint32_t GetTimerTimeout (void);

  uint32_t GetSuccessThreshold (void);

  void SetTimerTimeout (uint32_t timerTimeout);

  void SetSuccessThreshold (uint32_t successThreshold);

};

} // namespace ns3

#endif /* ARF_WIFI_MANAGER_H */