/* -*- 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 <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-stream.h"

#include "wifi-phy.h"

#include "wifi-mode.h"

#include "wifi-preamble.h"

#include "wifi-phy-standard.h"

#include "interference-helper.h"

namespace ns3 {

class YansWifiChannel;

class WifiPhyStateHelper;

/**

 * \brief 802.11 PHY layer model

 * \ingroup wifi

 *

 * 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);

  /**

   * \brief Set channel number.

   *

   * Channel center frequency = Channel starting frequency + 5 MHz * nch

   *

   * where Starting channel frequency is standard-dependent, see SetStandard()

   * as defined in IEEE 802.11-2007 17.3.8.3.2.

   *

   * YansWifiPhy can switch among different channels. Basically, YansWifiPhy

   * has a private attribute m_channelNumber that identifies the channel the

   * PHY operates on. Channel switching cannot interrupt an ongoing transmission.

   * When PHY is in TX state, the channel switching is postponed until the end

   * of the current transmission. When the PHY is in RX state, the channel

   * switching causes the drop of the synchronized packet.

   */

  void SetChannelNumber (uint16_t id);

  /// Return current channel number, see SetChannelNumber()

  uint16_t GetChannelNumber () const;

  /// Return current center channel frequency in MHz, see SetChannelNumber()

  double GetChannelFrequencyMhz () const;

  void StartReceivePacket (Ptr<Packet> packet,

                           double rxPowerDbm,

                           WifiPreamble preamble);

  void SetRxNoiseFigure (double noiseFigureDb);

  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);

  void SetCcaMode1Threshold (double threshold);

  void SetErrorRateModel (Ptr<ErrorRateModel> rate);

  void SetDevice (Ptr<Object> device);

  void SetMobility (Ptr<Object> mobility);

  double GetRxNoiseFigure (void) const;

  double GetTxGain (void) const;

  double GetRxGain (void) const;

  double GetEdThreshold (void) const;

  double GetCcaMode1Threshold (void) const;

  Ptr<ErrorRateModel> GetErrorRateModel (void) const;

  Ptr<Object> GetDevice (void) const;

  Ptr<Object> GetMobility (void);

  virtual double GetTxPowerStart (void) const;

  virtual double GetTxPowerEnd (void) const;

  virtual uint32_t GetNTxPower (void) const;

  virtual void SetReceiveOkCallback (WifiPhy::RxOkCallback callback);

  virtual void SetReceiveErrorCallback (WifiPhy::RxErrorCallback callback);

  virtual void RegisterListener (WifiPhyListener *listener);

  virtual bool IsStateCcaBusy (void);

  virtual bool IsStateIdle (void);

  virtual bool IsStateBusy (void);

  virtual bool IsStateRx (void);

  virtual bool IsStateTx (void);

  virtual bool IsStateSwitching (void);

  virtual Time GetStateDuration (void);

  virtual Time GetDelayUntilIdle (void);

  virtual Time GetLastRxStartTime (void) 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;

  virtual void ConfigureStandard (enum WifiPhyStandard standard);

 /**

  * Assign a fixed random variable stream number to the random variables

  * used by this model.  Return the number of streams (possibly zero) that

  * have been assigned.

  *

  * \param stream first stream index to use

  * \return the number of stream indices assigned by this model

  */

  int64_t AssignStreams (int64_t stream);

private:

  YansWifiPhy (const YansWifiPhy &o);

  virtual void DoDispose (void);

  void Configure80211a (void);

  void Configure80211b (void);

  void Configure80211g (void);

  void Configure80211_10Mhz (void);

  void Configure80211_5Mhz ();

  void ConfigureHolland (void);

  void Configure80211p_CCH (void);

  void Configure80211p_SCH (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;

  double GetPowerDbm (uint8_t power) const;

  void EndReceive (Ptr<Packet> packet, Ptr<InterferenceHelper::Event> event);

private:

  double   m_edThresholdW;

  double   m_ccaMode1ThresholdW;

  double   m_txGainDb;

  double   m_rxGainDb;

  double   m_txPowerBaseDbm;

  double   m_txPowerEndDbm;

  uint32_t m_nTxPower;

  Ptr<YansWifiChannel> m_channel;

  /**

   * This vector holds the set of transmission modes that this

   * WifiPhy(-derived class) can support. In conversation we call this

   * the DeviceRateSet (not a term you'll find in the standard), and

   * it is a superset of standard-defined parameters such as the

   * OperationalRateSet, and the BSSBasicRateSet (which, themselves,

   * have a superset/subset relationship).

   *

   * Mandatory rates relevant to this WifiPhy can be found by

   * iterating over this vector looking for WifiMode objects for which

   * WifiMode::IsMandatory() is true.

   *

   * A quick note is appropriate here (well, here is as good a place

   * as any I can find)...

   *

   * In the standard there is no text that explicitly precludes

   * production of a device that does not support some rates that are

   * mandatory (according to the standard) for PHYs that the device

   * happens to fully or partially support.

   *

   * This approach is taken by some devices which choose to only support,

   * for example, 6 and 9 Mbps ERP-OFDM rates for cost and power

   * consumption reasons (i.e., these devices don't need to be designed

   * for and waste current on the increased linearity requirement of

   * higher-order constellations when 6 and 9 Mbps more than meet their

   * data requirements). The wording of the standard allows such devices

   * to have an OperationalRateSet which includes 6 and 9 Mbps ERP-OFDM

   * rates, despite 12 and 24 Mbps being "mandatory" rates for the

   * ERP-OFDM PHY.

   *

   * Now this doesn't actually have any impact on code, yet. It is,

   * however, something that we need to keep in mind for the

   * future. Basically, the key point is that we can't be making

   * assumptions like "the Operational Rate Set will contain all the

   * mandatory rates".

   */

  WifiModeList m_deviceRateSet;

  EventId m_endRxEvent;

  /// Provides uniform random variables.

  Ptr<UniformRandomVariable> m_random;

  /// Standard-dependent center frequency of 0-th channel, MHz

  double m_channelStartingFrequency;

  Ptr<WifiPhyStateHelper> m_state;

  InterferenceHelper m_interference;

  Time m_channelSwitchDelay;

};

} // namespace ns3

#endif /* YANS_WIFI_PHY_H */