/* -*- 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 WIFI_PHY_H

#define WIFI_PHY_H

#include <stdint.h>

#include "ns3/callback.h"

#include "ns3/packet.h"

#include "ns3/object.h"

#include "ns3/nstime.h"

#include "ns3/ptr.h"

#include "wifi-mode.h"

#include "wifi-preamble.h"

#include "wifi-phy-standard.h"

#include "ns3/traced-callback.h"

#include "wifi-tx-vector.h"

namespace ns3 {

class WifiChannel;

class NetDevice;

/**

 * \brief receive notifications about phy events.

 */

class WifiPhyListener

{

public:

  virtual ~WifiPhyListener ();

  /**

   * \param duration the expected duration of the packet reception.

   *

   * We have received the first bit of a packet. We decided

   * that we could synchronize on this packet. It does not mean

   * we will be able to successfully receive completely the

   * whole packet. It means that we will report a BUSY status until

   * one of the following happens:

   *   - NotifyRxEndOk

   *   - NotifyRxEndError

   *   - NotifyTxStart

   */

  virtual void NotifyRxStart (Time duration) = 0;

  /**

   * We have received the last bit of a packet for which

   * NotifyRxStart was invoked first and, the packet has

   * been successfully received.

   */

  virtual void NotifyRxEndOk (void) = 0;

  /**

   * We have received the last bit of a packet for which

   * NotifyRxStart was invoked first and, the packet has

   * _not_ been successfully received.

   */

  virtual void NotifyRxEndError (void) = 0;

  /**

   * \param duration the expected transmission duration.

   * \param txPowerDbm the nominal tx power in dBm

   *

   * We are about to send the first bit of the packet.

   * We do not send any event to notify the end of

   * transmission. Listeners should assume that the

   * channel implicitely reverts to the idle state

   * unless they have received a cca busy report.

   */

  virtual void NotifyTxStart (Time duration, double txPowerDbm) = 0;

  /**

   * \param duration the expected busy duration.

   *

   * This method does not really report a real state

   * change as opposed to the other methods in this class.

   * It merely reports that, unless the medium is reported

   * busy through NotifyTxStart or NotifyRxStart/End,

   * it will be busy as defined by the currently selected

   * CCA mode.

   *

   * Typical client code which wants to have a clear picture

   * of the CCA state will need to keep track of the time at

   * which the last NotifyCcaBusyStart method is called and

   * what duration it reported.

   */

  virtual void NotifyMaybeCcaBusyStart (Time duration) = 0;

  /**

   * \param duration the expected channel switching duration.

   *

   * We do not send any event to notify the end of

   * channel switching. Listeners should assume that the

   * channel implicitely reverts to the idle or busy states.

   */

  virtual void NotifySwitchingStart (Time duration) = 0;

  /**

   * Notify listeners that we went to sleep

   */

  virtual void NotifySleep (void) = 0;

  /**

   * Notify listeners that we woke up

   */

  virtual void NotifyWakeup (void) = 0;

};

/**

 * \brief 802.11 PHY layer model

 * \ingroup wifi

 *

 */

class WifiPhy : public Object

{

public:

  /**

   * The state of the PHY layer.

   */

  enum State

  {

    /**

     * The PHY layer is IDLE.

     */

    IDLE,

    /**

     * The PHY layer has sense the medium busy through the CCA mechanism

     */

    CCA_BUSY,

    /**

     * The PHY layer is sending a packet.

     */

    TX,

    /**

     * The PHY layer is receiving a packet.

     */

    RX,

    /**

     * The PHY layer is switching to other channel.

     */

    SWITCHING,

    /**

     * The PHY layer is sleeping.

     */

    SLEEP

  };

  /**

   * arg1: packet received successfully

   * arg2: snr of packet

   * arg3: TXVECTOR of packet

   * arg4: type of preamble used for packet.

   */

  typedef Callback<void,Ptr<Packet>, double, WifiTxVector, enum WifiPreamble> RxOkCallback;

  /**

   * arg1: packet received unsuccessfully

   * arg2: snr of packet

   */

  typedef Callback<void,Ptr<const Packet>, double> RxErrorCallback;

  static TypeId GetTypeId (void);

  WifiPhy ();

  virtual ~WifiPhy ();

  /**

   * Return the minimum available transmission power level (dBm).

   *

   * \return the minimum available transmission power level in dBm

   */

  virtual double GetTxPowerStart (void) const = 0;

  /**

   * Return the maximum available transmission power level (dBm).

   *

   * \return the maximum available transmission power level in dBm

   */

  virtual double GetTxPowerEnd (void) const = 0;

  /**

   * \return the number of tx power levels available for this PHY.

   */

  virtual uint32_t GetNTxPower (void) const = 0;

  /**

   * \param callback the callback to invoke

   *        upon successful packet reception.

   */

  virtual void SetReceiveOkCallback (RxOkCallback callback) = 0;

  /**

   * \param callback the callback to invoke

   *        upon erroneous packet reception.

   */

  virtual void SetReceiveErrorCallback (RxErrorCallback callback) = 0;

  /**

   * \param packet the packet to send

   * \param txvector the txvector that has tx parameters such as mode, the transmission mode to use to send

   *        this packet, and txPowerLevel, a power level to use to send this packet. The real transmission

   *        power is calculated as txPowerMin + txPowerLevel * (txPowerMax - txPowerMin) / nTxLevels

   * \param preamble the type of preamble to use to send this packet.

   * \param packetType the type of the packet 0 is not A-MPDU, 1 is a MPDU that is part of an A-MPDU and 2 is the last MPDU in an A-MPDU

   */

  virtual void SendPacket (Ptr<const Packet> packet, WifiTxVector txvector, enum WifiPreamble preamble, uint8_t packetType) = 0;

  /**

   * \param listener the new listener

   *

   * Add the input listener to the list of objects to be notified of

   * PHY-level events.

   */

  virtual void RegisterListener (WifiPhyListener *listener) = 0;

  /**

   * \param listener the listener to be unregistered

   *

   * Remove the input listener from the list of objects to be notified of

   * PHY-level events.

   */

  virtual void UnregisterListener (WifiPhyListener *listener) = 0;

  /**

   * Put in sleep mode.

   */

  virtual void SetSleepMode (void) = 0;

  /**

   * Resume from sleep mode.

   */

  virtual void ResumeFromSleep (void) = 0;

  /**

   * \return true of the current state of the PHY layer is WifiPhy::IDLE, false otherwise.

   */

  virtual bool IsStateIdle (void) = 0;

  /**

   * \return true of the current state of the PHY layer is WifiPhy::CCA_BUSY, false otherwise.

   */

  virtual bool IsStateCcaBusy (void) = 0;

  /**

   * \return true of the current state of the PHY layer is not WifiPhy::IDLE, false otherwise.

   */

  virtual bool IsStateBusy (void) = 0;

  /**

   * \return true of the current state of the PHY layer is WifiPhy::RX, false otherwise.

   */

  virtual bool IsStateRx (void) = 0;

  /**

   * \return true of the current state of the PHY layer is WifiPhy::TX, false otherwise.

   */

  virtual bool IsStateTx (void) = 0;

  /**

   * \return true of the current state of the PHY layer is WifiPhy::SWITCHING, false otherwise.

   */

  virtual bool IsStateSwitching (void) = 0;

  /**

   * \return true if the current state of the PHY layer is WifiPhy::SLEEP, false otherwise.

   */

  virtual bool IsStateSleep (void) = 0;

  /**

   * \return the amount of time since the current state has started.

   */

  virtual Time GetStateDuration (void) = 0;

  /**

   * \return the predicted delay until this PHY can become WifiPhy::IDLE.

   *

   * The PHY will never become WifiPhy::IDLE _before_ the delay returned by

   * this method but it could become really idle later.

   */

  virtual Time GetDelayUntilIdle (void) = 0;

  /**

   * Return the start time of the last received packet.

   *

   * \return the start time of the last received packet

   */

  virtual Time GetLastRxStartTime (void) const = 0;

  /**

   * \param size the number of bytes in the packet to send

   * \param txvector the transmission parameters used for this packet

   * \param preamble the type of preamble to use for this packet.

   * \param frequency the channel center frequency (MHz)

   * \param packetType the type of the packet 0 is not A-MPDU, 1 is a MPDU that is part of an A-MPDU  and 2 is the last MPDU in an A-MPDU

   * \param incFlag this flag is used to indicate that the static variables need to be update or not. This function is called a couple of times for the same packet so static variables should not be increased each time. 

   * \return the total amount of time this PHY will stay busy for

   *          the transmission of these bytes.

   */

  Time CalculateTxDuration (uint32_t size, WifiTxVector txvector, enum WifiPreamble preamble, double frequency, uint8_t packetType, uint8_t incFlag);

  /**

   * \param txvector the transmission parameters used for this packet

   * \param preamble the type of preamble to use for this packet.

   * \return the total amount of time this PHY will stay busy for the transmission of the plcp.

   */

  Time CalculatePlcpDuration (WifiTxVector txvector, enum WifiPreamble preamble);

  /**

   * \param preamble the type of preamble

   * \param txvector the transmission parameters used for this packet

   * \return the training symbol duration

   */

  static Time GetPlcpHtTrainingSymbolDuration (WifiPreamble preamble, WifiTxVector txvector);

  /**

   * \param payloadMode the WifiMode use for the transmission of the payload

   * \param preamble the type of preamble

   * 

   * \return the WifiMode used for the transmission of the HT-SIG in Mixed Format and greenfield format PLCP header 

   */

  static WifiMode GetMFPlcpHeaderMode (WifiMode payloadMode, WifiPreamble preamble);

  /** 

   * \param preamble the type of preamble

   * 

   * \return the duration of the HT-SIG in Mixed Format and greenfield format PLCP header 

   */

  static Time GetPlcpHtSigHeaderDuration (WifiPreamble preamble);

  /** 

   * \param payloadMode the WifiMode use for the transmission of the payload

   * \param preamble the type of preamble

   * 

   * \return the WifiMode used for the transmission of the PLCP header 

   */

  static WifiMode GetPlcpHeaderMode (WifiMode payloadMode, WifiPreamble preamble);

  /**

   * \param payloadMode the WifiMode use for the transmission of the payload

   * \param preamble the type of preamble

   * 

   * \return the duration of the PLCP header

   */

  static Time GetPlcpHeaderDuration (WifiMode payloadMode, WifiPreamble preamble);

  /** 

   * \param payloadMode the WifiMode use for the transmission of the payload

   * \param preamble the type of preamble 

   * 

   * \return the duration of the PLCP preamble

   */

  static Time GetPlcpPreambleDuration (WifiMode payloadMode, WifiPreamble preamble);

  /** 

   * \param size the number of bytes in the packet to send

   * \param txvector the transmission parameters used for this packet

   * \param preamble the type of preamble to use for this packet.

   * \param frequency the channel center frequency (MHz)

   * \param packetType the type of the packet 0 is not A-MPDU, 1 is a MPDU that is part of an A-MPDU  and 2 is the last MPDU in an A-MPDU

   * \param incFlag this flag is used to indicate that the static variables need to be update or not. This function is called a couple of times for the same packet so static variables should not be increased each time

   * 

   * \return the duration of the payload

   */

  Time GetPayloadDuration (uint32_t size, WifiTxVector txvector, WifiPreamble preamble, double frequency, uint8_t packetType, uint8_t incFlag);

  /**

   * The WifiPhy::GetNModes() and WifiPhy::GetMode() methods are used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception modes that this WifiPhy(-derived class)

   * can support - a set of WifiMode objects which we call the

   * DeviceRateSet, and which is stored as WifiPhy::m_deviceRateSet.

   *

   * It is important to note that the DeviceRateSet is a superset (not

   * necessarily proper) of the OperationalRateSet (which is

   * logically, if not actually, a property of the associated

   * WifiRemoteStationManager), which itself is a superset (again, not

   * necessarily proper) of the BSSBasicRateSet.

   *

   * \return the number of transmission modes supported by this PHY.

   *

   * \sa WifiPhy::GetMode()

   */

  virtual uint32_t GetNModes (void) const = 0;

  /**

   * The WifiPhy::GetNModes() and WifiPhy::GetMode() methods are used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception modes that this WifiPhy(-derived class)

   * can support - a set of WifiMode objects which we call the

   * DeviceRateSet, and which is stored as WifiPhy::m_deviceRateSet.

   *

   * It is important to note that the DeviceRateSet is a superset (not

   * necessarily proper) of the OperationalRateSet (which is

   * logically, if not actually, a property of the associated

   * WifiRemoteStationManager), which itself is a superset (again, not

   * necessarily proper) of the BSSBasicRateSet.

   *

   * \param mode index in array of supported modes

   * \return the mode whose index is specified.

   *

   * \sa WifiPhy::GetNModes()

   */

  virtual WifiMode GetMode (uint32_t mode) const = 0;

  /**

   * Check if the given WifiMode is supported by the PHY.

   *

   * \param mode the wifi mode to check

   * \return true if the given mode is supported,

   *         false otherwise

   */

  virtual bool IsModeSupported (WifiMode mode) const = 0;

  /**

   * \param txMode the transmission mode

   * \param ber the probability of bit error rate

   * \return the minimum snr which is required to achieve

   *          the requested ber for the specified transmission mode. (W/W)

   */

  virtual double CalculateSnr (WifiMode txMode, double ber) const = 0;

   /**

   * The WifiPhy::NBssMembershipSelectors() method is used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception modes that this WifiPhy(-derived class)

   * can support - a set of WifiMode objects which we call the

   * BssMembershipSelectorSet, and which is stored as WifiPhy::m_bssMembershipSelectorSet.

   *

   * This was introduced with 11n

   *

   * \return the memebership selector whose index is specified.

   */

  virtual uint32_t GetNBssMembershipSelectors (void) const=0;

   /**

   * The WifiPhy::BssMembershipSelector() method is used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception modes that this WifiPhy(-derived class)

   * can support - a set of WifiMode objects which we call the

   * BssMembershipSelectorSet, and which is stored as WifiPhy::m_bssMembershipSelectorSet.

   *

   * This was introduced with 11n

   *

   * \param selector index in array of supported memberships

   * \return the memebership selector whose index is specified.

   */

  virtual uint32_t GetBssMembershipSelector (uint32_t selector) const=0;

  /**

   * The WifiPhy::GetMembershipSelectorModes() method is used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception modes that this WifiPhy(-derived class)

   * can support - a set of WifiMode objects which we call the

   * BssMembershipSelectorSet, and which is stored as WifiPhy::m_bssMembershipSelectorSet.

   *

   * This was introduced with 11n

   *

   * \param selector index in array of supported memberships

   * \return a WifiModeList that contains the WifiModes associrated with the selected index.

   *

   * \sa WifiPhy::GetMembershipSelectorModes()

   */

  virtual WifiModeList GetMembershipSelectorModes(uint32_t selector)=0;

  /**

   * The WifiPhy::GetNMcs() method is used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception MCS indexes that this WifiPhy(-derived class)

   * can support - a set of MCS indexes which we call the

   * DeviceMcsSet, and which is stored as WifiPhy::m_deviceMcsSet.

   *

   * This was introduced with 11n

   *

   * \return the MCS index whose index is specified.

   */

  virtual uint8_t GetNMcs (void) const=0;

  /**

   * The WifiPhy::GetMcs() method is used

   * (e.g., by a WifiRemoteStationManager) to determine the set of

   * transmission/reception MCS indexes that this WifiPhy(-derived class)

   * can support - a set of MCS indexes which we call the

   * DeviceMcsSet, and which is stored as WifiPhy::m_deviceMcsSet.

   *

   * This was introduced with 11n

   *

   * \param mcs index in array of supported MCS

   * \return the MCS index whose index is specified.

   */

  virtual uint8_t GetMcs (uint8_t mcs) const=0;

  /**