mac-low.h

Go to the documentation of this file.

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2005, 2006 INRIA
 * Copyright (c) 2009 MIRKO BANCHI
 *
 * 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>
 * Author: Mirko Banchi <mk.banchi@gmail.com>
 */
#ifndef MAC_LOW_H
#define MAC_LOW_H

#include <vector>
#include <stdint.h>
#include <ostream>
#include <map>

#include "wifi-mac-header.h"
#include "wifi-mode.h"
#include "wifi-preamble.h"
#include "wifi-remote-station-manager.h"
#include "ctrl-headers.h"
#include "mgt-headers.h"
#include "block-ack-agreement.h"
#include "ns3/mac48-address.h"
#include "ns3/callback.h"
#include "ns3/event-id.h"
#include "ns3/packet.h"
#include "ns3/nstime.h"
#include "qos-utils.h"
#include "block-ack-cache.h"
#include "wifi-tx-vector.h"

namespace ns3 {

class WifiPhy;
class WifiMac;
class EdcaTxopN;

class MacLowTransmissionListener
{
public:
  MacLowTransmissionListener ();
  virtual ~MacLowTransmissionListener ();

  virtual void GotCts (double snr, WifiMode txMode) = 0;
  virtual void MissedCts (void) = 0;
  virtual void GotAck (double snr, WifiMode txMode) = 0;
  virtual void MissedAck (void) = 0;
  virtual void GotBlockAck (const CtrlBAckResponseHeader *blockAck, Mac48Address source);
  virtual void MissedBlockAck (void);
  virtual void StartNext (void) = 0;

  virtual void Cancel (void) = 0;   

  virtual void EndTxNoAck (void) = 0;

};


class MacLowDcfListener
{
public:
  MacLowDcfListener ();
  virtual ~MacLowDcfListener ();
  virtual void NavStart (Time duration) = 0;
  virtual void NavReset (Time duration) = 0;
  virtual void AckTimeoutStart (Time duration) = 0;
  virtual void AckTimeoutReset () = 0;
  virtual void CtsTimeoutStart (Time duration) = 0;
  virtual void CtsTimeoutReset () = 0;
};

class MacLowBlockAckEventListener
{
public:
  MacLowBlockAckEventListener ();
  virtual ~MacLowBlockAckEventListener ();
  virtual void BlockAckInactivityTimeout (Mac48Address originator, uint8_t tid) = 0;
};

class MacLowTransmissionParameters
{
public:
  MacLowTransmissionParameters ();

  void EnableAck (void);
  void EnableFastAck (void);
  void EnableSuperFastAck (void);
  void EnableBasicBlockAck (void);
  void EnableCompressedBlockAck (void);
  void EnableMultiTidBlockAck (void);
  void EnableRts (void);
  void EnableNextData (uint32_t size);

  void EnableOverrideDurationId (Time durationId);

  void DisableAck (void);
  void DisableRts (void);
  void DisableNextData (void);
  void DisableOverrideDurationId (void);

  bool MustWaitAck (void) const;
  bool MustWaitNormalAck (void) const;
  bool MustWaitFastAck (void) const;
  bool MustWaitSuperFastAck (void) const;
  bool MustWaitBasicBlockAck (void) const;
  bool MustWaitCompressedBlockAck (void) const;
  bool MustWaitMultiTidBlockAck (void) const;
  bool MustSendRts (void) const;
  bool HasDurationId (void) const;
  Time GetDurationId (void) const;
  bool HasNextPacket (void) const;
  uint32_t GetNextPacketSize (void) const;

private:

  friend std::ostream &operator << (std::ostream &os, const MacLowTransmissionParameters &params);
  uint32_t m_nextSize;
  enum
  {
    ACK_NONE,
    ACK_NORMAL,
    ACK_FAST,
    ACK_SUPER_FAST,
    BLOCK_ACK_BASIC,
    BLOCK_ACK_COMPRESSED,
    BLOCK_ACK_MULTI_TID
  } m_waitAck;
  bool m_sendRts;
  Time m_overrideDurationId;
};

std::ostream &operator << (std::ostream &os, const MacLowTransmissionParameters &params);


class MacLow : public Object
{
public:
  typedef Callback<void, Ptr<Packet>, const WifiMacHeader*> MacLowRxCallback;

  MacLow ();
  virtual ~MacLow ();

  void SetPhy (Ptr<WifiPhy> phy);
  void SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> manager);

  void SetAddress (Mac48Address ad);
  void SetAckTimeout (Time ackTimeout);
  void SetBasicBlockAckTimeout (Time blockAckTimeout);
  void SetCompressedBlockAckTimeout (Time blockAckTimeout);
  void SetCtsToSelfSupported (bool enable);
  void SetCtsTimeout (Time ctsTimeout);
  void SetSifs (Time sifs);
  void SetRifs (Time rifs);
  void SetSlotTime (Time slotTime);
  void SetPifs (Time pifs);
  void SetBssid (Mac48Address ad);
  void SetPromisc (void);
  bool GetCtsToSelfSupported () const;
  Mac48Address GetAddress (void) const;
  Time GetAckTimeout (void) const;
  Time GetBasicBlockAckTimeout () const;
  Time GetCompressedBlockAckTimeout () const;
  Time GetCtsTimeout (void) const;
  Time GetSifs (void) const;
  Time GetSlotTime (void) const;
  Time GetPifs (void) const;
  Time GetRifs (void) const;
  Mac48Address GetBssid (void) const;
  bool IsPromisc (void) const;

  void SetRxCallback (Callback<void,Ptr<Packet>,const WifiMacHeader *> callback);
  void RegisterDcfListener (MacLowDcfListener *listener);

  Time CalculateTransmissionTime (Ptr<const Packet> packet,
                                  const WifiMacHeader* hdr,
                                  const MacLowTransmissionParameters& parameters) const;

  void StartTransmission (Ptr<const Packet> packet,
                          const WifiMacHeader* hdr,
                          MacLowTransmissionParameters parameters,
                          MacLowTransmissionListener *listener);

  void ReceiveOk (Ptr<Packet> packet, double rxSnr, WifiMode txMode, WifiPreamble preamble);
  void ReceiveError (Ptr<const Packet> packet, double rxSnr);
  void NotifySwitchingStartNow (Time duration);
  void CreateBlockAckAgreement (const MgtAddBaResponseHeader *respHdr,
                                Mac48Address originator,
                                uint16_t startingSeq);
  void DestroyBlockAckAgreement (Mac48Address originator, uint8_t tid);
  void RegisterBlockAckListenerForAc (enum AcIndex ac, MacLowBlockAckEventListener *listener);
protected:
  virtual WifiTxVector GetDataTxVector (Ptr<const Packet> packet, const WifiMacHeader *hdr) const;
private:
  void CancelAllEvents (void);
  uint32_t GetAckSize (void) const;
  uint32_t GetBlockAckSize (enum BlockAckType type) const;
  uint32_t GetRtsSize (void) const;
  uint32_t GetCtsSize (void) const;
  uint32_t GetSize (Ptr<const Packet> packet, const WifiMacHeader *hdr) const;
  void ForwardDown (Ptr<const Packet> packet, const WifiMacHeader *hdr,
                    WifiTxVector txVector, WifiPreamble preamble);
  WifiTxVector GetRtsTxVector (Ptr<const Packet> packet, const WifiMacHeader *hdr) const;
  WifiTxVector GetCtsTxVector (Mac48Address to, WifiMode rtsTxMode) const;
  WifiTxVector GetAckTxVector (Mac48Address to, WifiMode dataTxMode) const;
  WifiTxVector GetBlockAckTxVector (Mac48Address to, WifiMode dataTxMode) const;

  WifiTxVector GetCtsToSelfTxVector (Ptr<const Packet> packet, const WifiMacHeader *hdr) const;

  WifiTxVector GetCtsTxVectorForRts (Mac48Address to, WifiMode rtsTxMode) const;
  WifiTxVector GetAckTxVectorForData (Mac48Address to, WifiMode dataTxMode) const;

  Time GetCtsDuration (WifiTxVector ctsTxVector) const;
  Time GetCtsDuration (Mac48Address to, WifiTxVector rtsTxVector) const;
  Time GetAckDuration (WifiTxVector ackTxVector) const;
  Time GetAckDuration (Mac48Address to, WifiTxVector dataTxVector) const;
  Time GetBlockAckDuration (Mac48Address to, WifiTxVector blockAckReqTxVector, enum BlockAckType type) const;

  bool NeedCtsToSelf (void);
  
  Time CalculateOverallTxTime (Ptr<const Packet> packet,
                               const WifiMacHeader* hdr,
                               const MacLowTransmissionParameters &params) const;
  void NotifyNav (Ptr<const Packet> packet,const WifiMacHeader &hdr, WifiMode txMode, WifiPreamble preamble);
  void DoNavResetNow (Time duration);
  bool DoNavStartNow (Time duration);
  bool IsNavZero (void) const;
  void NotifyAckTimeoutStartNow (Time duration);
  void NotifyAckTimeoutResetNow ();
  void NotifyCtsTimeoutStartNow (Time duration);
  void NotifyCtsTimeoutResetNow ();

  void NavCounterResetCtsMissed (Time rtsEndRxTime);

  /* Event handlers */
  void NormalAckTimeout (void);
  void FastAckTimeout (void);
  void SuperFastAckTimeout (void);
  void FastAckFailedTimeout (void);
  void BlockAckTimeout (void);
  void CtsTimeout (void);
  void SendCtsToSelf (void);
  void SendCtsAfterRts (Mac48Address source, Time duration, WifiMode txMode, double rtsSnr);
  void SendAckAfterData (Mac48Address source, Time duration, WifiMode dataTxMode, double dataSnr);
  void SendDataAfterCts (Mac48Address source, Time duration, WifiMode txMode);
  void WaitSifsAfterEndTx (void);
  void EndTxNoAck (void);

  void SendRtsForPacket (void);
  void SendDataPacket (void);
  void StartDataTxTimers (WifiTxVector dataTxVector);
  virtual void DoDispose (void);
  void RxCompleteBufferedPacketsWithSmallerSequence (uint16_t seq, Mac48Address originator, uint8_t tid);
  void RxCompleteBufferedPacketsUntilFirstLost (Mac48Address originator, uint8_t tid);
  /*
   * This method checks if exists a valid established block ack agreement.
   * If there is, store the packet without pass it up to WifiMac. The packet is buffered
   * in order of increasing sequence control field. All comparison are performed
   * circularly modulo 2^12.
   */
  bool StoreMpduIfNeeded (Ptr<Packet> packet, WifiMacHeader hdr);
  void SendBlockAckAfterBlockAckRequest (const CtrlBAckRequestHeader reqHdr, Mac48Address originator,
                                         Time duration, WifiMode blockAckReqTxMode);
  void SendBlockAckResponse (const CtrlBAckResponseHeader* blockAck, Mac48Address originator, bool immediate,
                             Time duration, WifiMode blockAckReqTxMode);
  void ResetBlockAckInactivityTimerIfNeeded (BlockAckAgreement &agreement);

  void SetupPhyMacLowListener (Ptr<WifiPhy> phy);

  Ptr<WifiPhy> m_phy; 
  Ptr<WifiRemoteStationManager> m_stationManager; 
  MacLowRxCallback m_rxCallback; 

  typedef std::vector<MacLowDcfListener *>::const_iterator DcfListenersCI;
  typedef std::vector<MacLowDcfListener *> DcfListeners;
  DcfListeners m_dcfListeners; 

  EventId m_normalAckTimeoutEvent;      
  EventId m_fastAckTimeoutEvent;        
  EventId m_superFastAckTimeoutEvent;   
  EventId m_fastAckFailedTimeoutEvent;  
  EventId m_blockAckTimeoutEvent;       
  EventId m_ctsTimeoutEvent;            
  EventId m_sendCtsEvent;               
  EventId m_sendAckEvent;               
  EventId m_sendDataEvent;              
  EventId m_waitSifsEvent;              
  EventId m_endTxNoAckEvent;            
  EventId m_navCounterResetCtsMissed;   
  EventId m_waitRifsEvent;              

  Ptr<Packet> m_currentPacket;              
  WifiMacHeader m_currentHdr;               
  MacLowTransmissionParameters m_txParams;  
  MacLowTransmissionListener *m_listener;   
  Mac48Address m_self;                      
  Mac48Address m_bssid;                     
  Time m_ackTimeout;                        
  Time m_basicBlockAckTimeout;              
  Time m_compressedBlockAckTimeout;         
  Time m_ctsTimeout;                        
  Time m_sifs;                              
  Time m_slotTime;                          
  Time m_pifs;                              
  Time m_rifs;                              

  Time m_lastNavStart;     
  Time m_lastNavDuration;  

  bool m_promisc;  

  class PhyMacLowListener * m_phyMacLowListener; 

  /*
   * BlockAck data structures.
   */
  typedef std::pair<Ptr<Packet>, WifiMacHeader> BufferedPacket;
  typedef std::list<BufferedPacket>::iterator BufferedPacketI;

  typedef std::pair<Mac48Address, uint8_t> AgreementKey;
  typedef std::pair<BlockAckAgreement, std::list<BufferedPacket> > AgreementValue;

  typedef std::map<AgreementKey, AgreementValue> Agreements;
  typedef std::map<AgreementKey, AgreementValue>::iterator AgreementsI;

  typedef std::map<AgreementKey, BlockAckCache> BlockAckCaches;
  typedef std::map<AgreementKey, BlockAckCache>::iterator BlockAckCachesI;

  Agreements m_bAckAgreements;
  BlockAckCaches m_bAckCaches;

  typedef std::map<AcIndex, MacLowBlockAckEventListener*> QueueListeners;
  QueueListeners m_edcaListeners;
  bool m_ctsToSelfSupported;
};

} // namespace ns3

#endif /* MAC_LOW_H */