/* -*-  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 YANS_WIFI_PHY_H

#define YANS_WIFI_PHY_H

#include <vector>

#include <list>

#include <stdint.h>

#include "ns3/callback.h"

#include "ns3/event-id.h"

#include "ns3/packet.h"

#include "ns3/object.h"

#include "ns3/traced-callback.h"

#include "ns3/nstime.h"

#include "ns3/ptr.h"

#include "ns3/random-variable.h"

#include "wifi-phy.h"

#include "wifi-mode.h"

#include "wifi-preamble.h"

#include "wifi-phy-standard.h"

namespace ns3 {

class RandomUniform;

class RxEvent;

class YansWifiChannel;

/**

 * \brief 802.11 PHY layer model

 *

 * This PHY implements a model of 802.11a. The model

 * implemented here is based on the model described

 * in "Yet Another Network Simulator", 

 * (http://cutebugs.net/files/wns2-yans.pdf).

 *

 *

 * This PHY model depends on a channel loss and delay

 * model as provided by the ns3::PropagationLossModel

 * and ns3::PropagationDelayModel classes, both of which are

 * members of the ns3::YansWifiChannel class.

 */

class YansWifiPhy : public WifiPhy

{

public:

  static TypeId GetTypeId (void);

  YansWifiPhy ();

  virtual ~YansWifiPhy ();

  void SetChannel (Ptr<YansWifiChannel> channel);

  void StartReceivePacket (Ptr<Packet> packet,

                           double rxPowerDbm,

                           WifiMode mode,

                           WifiPreamble preamble);

  void SetStandard (enum WifiPhyStandard standard);

  void SetRxNoise (double ratio);

  void SetTxPowerStart (double start);

  void SetTxPowerEnd (double end);

  void SetNTxPower (uint32_t n);

  void SetTxGain (double gain);

  void SetRxGain (double gain);

  void SetEdThreshold (double threshold);

  double GetRxNoise (void) const;

  double GetTxGain (void) const;

  double GetRxGain (void) const;

  double GetEdThreshold (void) const;

  virtual double GetTxPowerStart (void) const;

  virtual double GetTxPowerEnd (void) const;

  virtual uint32_t GetNTxPower (void) const;

  virtual void SetReceiveOkCallback (WifiPhy::SyncOkCallback callback);

  virtual void SetReceiveErrorCallback (WifiPhy::SyncErrorCallback callback);

  virtual void SendPacket (Ptr<const Packet> packet, WifiMode mode, enum WifiPreamble preamble, uint8_t txPowerLevel);

  virtual void RegisterListener (WifiPhyListener *listener);

  virtual bool IsStateCcaBusy (void);

  virtual bool IsStateIdle (void);

  virtual bool IsStateBusy (void);

  virtual bool IsStateSync (void);

  virtual bool IsStateTx (void);

  virtual Time GetStateDuration (void);

  virtual Time GetDelayUntilIdle (void);

  virtual Time GetLastRxStartTime (void) const;

  virtual Time CalculateTxDuration (uint32_t size, WifiMode payloadMode, enum WifiPreamble preamble) const;

  virtual uint32_t GetNModes (void) const;

  virtual WifiMode GetMode (uint32_t mode) const;

  virtual double CalculateSnr (WifiMode txMode, double ber) const;

  virtual Ptr<WifiChannel> GetChannel (void) const;

private:

  class NiChange {

  public:

    NiChange (Time time, double delta);

    Time GetTime (void) const;

    double GetDelta (void) const;

    bool operator < (NiChange const &o) const;

  private:

    Time m_time;

    double m_delta;

  };

  typedef std::vector<WifiMode> Modes;

  typedef std::list<Ptr<RxEvent> > Events;

  typedef std::vector <NiChange> NiChanges;

private:

  virtual void DoDispose (void);

  void Configure80211aParameters (void);

  void PrintModes (void) const;

  void Configure80211a (void);

  void ConfigureHolland (void);

  double GetEdThresholdW (void) const;

  double DbmToW (double dbm) const;

  double DbToRatio (double db) const;

  double WToDbm (double w) const;

  double RatioToDb (double ratio) const;

  Time GetMaxPacketDuration (void) const;

  void CancelRx (void);

  double GetPowerDbm (uint8_t power) const;

  void AppendEvent (Ptr<RxEvent> event);

  double CalculateNoiseInterferenceW (Ptr<RxEvent> event, NiChanges *ni) const;

  double CalculateSnr (double signal, double noiseInterference, WifiMode mode) const;

  double CalculateChunkSuccessRate (double snir, Time delay, WifiMode mode) const;

  double CalculatePer (Ptr<const RxEvent> event, NiChanges *ni) const;

  void EndSync (Ptr<Packet> packet, Ptr<RxEvent> event);

  double Log2 (double val) const;

  double GetBpskBer (double snr, uint32_t signalSpread, uint32_t phyRate) const;

  double GetQamBer (double snr, unsigned int m, uint32_t signalSpread, uint32_t phyRate) const;

  uint32_t Factorial (uint32_t k) const;

  double Binomial (uint32_t k, double p, uint32_t n) const;

  double CalculatePdOdd (double ber, unsigned int d) const;

  double CalculatePdEven (double ber, unsigned int d) const;

  double CalculatePd (double ber, unsigned int d) const;

  double GetFecBpskBer (double snr, double nbits, 

                        uint32_t signalSpread, uint32_t phyRate,

                        uint32_t dFree, uint32_t adFree) const;

  double GetFecQamBer (double snr, uint32_t nbits, 

                       uint32_t signalSpread,

                       uint32_t phyRate,

                       uint32_t m, uint32_t dfree,

                       uint32_t adFree, uint32_t adFreePlusOne) const;

  double GetChunkSuccessRate (WifiMode mode, double snr, uint32_t nbits) const;

private:

  uint64_t m_txPrepareDelayUs;

  uint64_t m_plcpLongPreambleDelayUs;

  uint64_t m_plcpShortPreambleDelayUs;

  WifiMode m_longPlcpHeaderMode;

  WifiMode m_shortPlcpHeaderMode;

  uint32_t m_plcpHeaderLength;

  Time     m_maxPacketDuration;

  double   m_edThresholdW; /* unit: W */

  double   m_txGainDb;

  double   m_rxGainDb;

  double   m_rxNoiseRatio;

  double   m_txPowerBaseDbm;

  double   m_txPowerEndDbm;

  uint32_t m_nTxPower;

  Ptr<YansWifiChannel> m_channel;

  Modes m_modes;

  EventId m_endSyncEvent;

  Events m_events;

  UniformVariable m_random;

  WifiPhyStandard m_standard;

};

} // namespace ns3

#endif /* YANS_WIFI_PHY_H */