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

/*

 * Copyright (c) 2005,2006,2007 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 WIFI_MODE_H

#define WIFI_MODE_H

#include <stdint.h>

#include <string>

#include <vector>

#include <ostream>

#include "ns3/attribute-helper.h"

#include "ns3/wifi-phy-standard.h"

namespace ns3 {

/**

 * This enumeration defines the modulation classes per IEEE

 * 802.11-2007, Section 9.6.1, Table 9-2.

 */

enum WifiModulationClass {

  /** Modulation class unknown or unspecified. A WifiMode with this

  WifiModulationClass has not been properly initialised. */

  WIFI_MOD_CLASS_UNKNOWN = 0,

  /** Infrared (IR) (Clause 16) */

  WIFI_MOD_CLASS_IR,

  /** Frequency-hopping spread spectrum (FHSS) PHY (Clause 14) */

  WIFI_MOD_CLASS_FHSS,

  /** DSSS PHY (Clause 15) and HR/DSSS PHY (Clause 18) */

  WIFI_MOD_CLASS_DSSS,

  /** ERP-PBCC PHY (19.6) */

  WIFI_MOD_CLASS_ERP_PBCC,

  /** DSSS-OFDM PHY (19.7) */

  WIFI_MOD_CLASS_DSSS_OFDM,

  /** ERP-OFDM PHY (19.5) */

  WIFI_MOD_CLASS_ERP_OFDM,

  /** OFDM PHY (Clause 17) */

  WIFI_MOD_CLASS_OFDM,

  /** HT PHY (Clause 20) */

  WIFI_MOD_CLASS_HT

};

/**

 * This enumeration defines the various convolutional coding rates

 * used for the OFDM transmission modes in the IEEE 802.11

 * standard. DSSS (for example) rates which do not have an explicit

 * coding stage in their generation should have this parameter set to

 * WIFI_CODE_RATE_UNDEFINED.

 */

enum WifiCodeRate {

  /** No explicit coding (e.g., DSSS rates) */

  WIFI_CODE_RATE_UNDEFINED,

  /** Rate 3/4 */

  WIFI_CODE_RATE_3_4,

  /** Rate 2/3 */

  WIFI_CODE_RATE_2_3,

  /** Rate 1/2 */

  WIFI_CODE_RATE_1_2

};

/**

 * \brief represent a single transmission mode

 *

 * A WifiMode is implemented by a single integer which is used

 * to lookup in a global array the characteristics of the

 * associated transmission mode. It is thus extremely cheap to

 * keep a WifiMode variable around.

 */

class WifiMode

{

 public:

  /**

   * \returns the number of Hz used by this signal

   */

  uint32_t GetBandwidth (void) const;

  /**

   * \returns the physical bit rate of this signal.

   *

   * If a transmission mode uses 1/2 FEC, and if its

   * data rate is 3Mbs, the phy rate is 6Mbs

   */

  uint32_t GetPhyRate (void) const;

  /**

   * \returns the data bit rate of this signal.

   */

  uint32_t GetDataRate (void) const;

  /**

   * \returns the coding rate of this transmission mode

   */

  enum WifiCodeRate GetCodeRate (void) const;

  /**

   * \returns the size of the modulation constellation.

   */

  uint8_t GetConstellationSize (void) const;

  /**

   * \returns a human-readable representation of this WifiMode

   * instance.

   */

  std::string GetUniqueName (void) const;

  /**

   * \returns true if this mode is a mandatory mode, false

   *          otherwise.

   */

  bool IsMandatory (void) const;

  /**

   * \returns the uid associated to this wireless mode.

   *

   * Each specific wireless mode should have a different uid.

   * For example, the 802.11b 1Mbs and the 802.11b 2Mbs modes

   * should have different uids.

   */

  uint32_t GetUid (void) const;

  /**

   *

   * \returns the Modulation Class (see IEEE 802.11-2007 Section

   * 9.6.1) to which this WifiMode belongs.

   */

  enum WifiModulationClass GetModulationClass () const;

  /**

   * Create an invalid WifiMode. Calling any method on the

   * instance created will trigger an assert. This is useful

   * to separate the declaration of a WifiMode variable from

   * its initialization.

   */

  WifiMode ();

  WifiMode (std::string name);

private:

  friend class WifiModeFactory;

  WifiMode (uint32_t uid);

  uint32_t m_uid;

};

bool operator == (const WifiMode &a, const WifiMode &b);

std::ostream & operator << (std::ostream & os, const WifiMode &mode);

std::istream & operator >> (std::istream &is, WifiMode &mode);

/**

 * \class ns3::WifiModeValue

 * \brief hold objects of type ns3::WifiMode

 */

ATTRIBUTE_HELPER_HEADER (WifiMode);

/**

 * In various parts of the code, folk are interested in maintaining a

 * list of transmission modes. The vector class provides a good basis

 * for this, but we here add some syntactic sugar by defining a

 * WifiModeList type, and a corresponding iterator.

 */

typedef std::vector<WifiMode> WifiModeList;

typedef WifiModeList::const_iterator WifiModeListIterator;

/**

 * \brief create WifiMode class instances and keep track of them.

 *

 * This factory ensures that each WifiMode created has a unique name

 * and assigns to each of them a unique integer.

 */

class WifiModeFactory

{

public:

  /**

   * \param uniqueName the name of the associated WifiMode. This name

   *        must be unique accross _all_ instances.

   * \param modClass the class of modulation

   * \param isMandatory true if this WifiMode is mandatory, false otherwise.

   * \param bandwidth the bandwidth (Hz) of the signal generated when the

   *        associated WifiMode is used.

   * \param dataRate the rate (bits/second) at which the user data is transmitted

   * \param codingRate if convolutional coding is used for this rate

   * then this parameter specifies the convolutional coding rate

   * used. If there is no explicit convolutional coding step (e.g.,

   * for DSSS rates) then the caller should set this parameter to

   * WIFI_CODE_RATE_UNCODED.

   * \param constellationSize the order of the constellation used.

   *

   * Create a WifiMode.

   */

  static WifiMode CreateWifiMode (std::string uniqueName,

                                  enum WifiModulationClass modClass,

                                  bool isMandatory,

                                  uint32_t bandwidth,

                                  uint32_t dataRate,

                                  enum WifiCodeRate codingRate,

                                  uint8_t constellationSize);

private:

  friend class WifiMode;  

  friend std::istream & operator >> (std::istream &is, WifiMode &mode);

  static WifiModeFactory *GetFactory ();

  WifiModeFactory ();

  /**

   * This is the data associated to a unique WifiMode.

   * The integer stored in a WifiMode is in fact an index

   * in an array of WifiModeItem objects.

   */

  struct WifiModeItem {

    std::string uniqueUid;

    uint32_t bandwidth;

    uint32_t dataRate;

    uint32_t phyRate;

    enum WifiModulationClass modClass;

    uint8_t constellationSize;

    enum WifiCodeRate codingRate;

    bool isMandatory;

  };

  WifiMode Search (std::string name);

  uint32_t AllocateUid (std::string uniqueName);

  WifiModeItem *Get (uint32_t uid);

  typedef std::vector<struct WifiModeItem> WifiModeItemList;

  WifiModeItemList m_itemList;

};

} // namespace ns3

#endif /* WIFI_MODE_H */