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

/*

 * Copyright (c) 2011 Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)

 *

 * 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: Giuseppe Piro  <g.piro@poliba.it>

 *         Marco Miozzo <mmiozzo@cttc.es>

 */

#ifndef TRACE_FADING_LOSS_MODEL_H

#define TRACE_FADING_LOSS_MODEL_H

#include <ns3/object.h>

#include <ns3/spectrum-propagation-loss-model.h>

#include <map>

#include "ns3/random-variable-stream.h"

#include <ns3/nstime.h>

namespace ns3 {

class MobilityModel;

/**

 * \ingroup lte

 *

 * \brief fading loss model based on precalculated fading traces

 */

class TraceFadingLossModel : public SpectrumPropagationLossModel

{

public:

  TraceFadingLossModel ();

  virtual ~TraceFadingLossModel ();

  static TypeId GetTypeId ();

  virtual void DoStart (void);

  /**

   * \brief The couple of mobility mnode that form a fading channel realization

   */

  typedef std::pair<Ptr<const MobilityModel>, Ptr<const MobilityModel> > ChannelRealizationId_t;

 /**

  * 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:

  /**

   * @param txPower set of values vs frequency representing the

   * transmission power. See SpectrumChannel for details.

   *

   * @param a sender mobility

   * @param b receiver mobility

   *

   * @return set of values vs frequency representing the received

   * power in the same units used for the txPower parameter.

   */

  Ptr<SpectrumValue> DoCalcRxPowerSpectralDensity (Ptr<const SpectrumValue> txPsd,

                                                   Ptr<const MobilityModel> a,

                                                   Ptr<const MobilityModel> b) const;

  /**

  * \brief Get the value for a particular sub channel and a given speed

  * \param subChannel the sub channel for which a value is requested

  * \param speed the relative speed of the two devices

  * \return the loss for a particular sub channel

  */

  double GetValue (int subChannel, double speed);

  void SetTraceFileName (std::string fileName);

  void SetTraceLength (Time t);

  void LoadTrace ();

  mutable std::map <ChannelRealizationId_t, int > m_windowOffsetsMap;

  mutable std::map <ChannelRealizationId_t, Ptr<UniformRandomVariable> > m_startVariableMap;

  /**

   * Vector with fading samples in time domain (for a fixed RB)

   */

  typedef std::vector<double> FadingTraceSample;

  /**

   * Vector collecting the time fading traces in the frequency domain (per RB)

   */

  typedef std::vector<FadingTraceSample> FadingTrace;

  std::string m_traceFile;

  FadingTrace m_fadingTrace;

  Time m_traceLength;

  uint32_t m_samplesNum;

  Time m_windowSize;

  uint8_t m_rbNum;

  mutable Time m_lastWindowUpdate;

  uint8_t m_timeGranularity;

};

} // namespace ns3

#endif /* TRACE_FADING_LOSS_MODEL_H */