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

/*

 * Copyright (c) 2008 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>

 */

#include "wifi-mac.h"

#include "dcf.h"

#include "ns3/uinteger.h"

#include "ns3/trace-source-accessor.h"

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (WifiMac);

Time

WifiMac::GetDefaultMaxPropagationDelay (void)

{

  // 1000m 

  return Seconds (1000.0 / 300000000.0);

}

Time

WifiMac::GetDefaultSlot (void)

{

  // 802.11-a specific

  return MicroSeconds (9);

}

Time

WifiMac::GetDefaultSifs (void)

{

  // 802.11-a specific

  return MicroSeconds (16);

}

Time

WifiMac::GetDefaultEifsNoDifs (void)

{

  return GetDefaultSifs () + GetDefaultCtsAckDelay ();

}

Time

WifiMac::GetDefaultCtsAckDelay (void)

{

  // 802.11-a specific: 6mb/s

  return MicroSeconds (44);

}

Time

WifiMac::GetDefaultCtsAckTimeout (void)

{

  /* Cts_Timeout and Ack_Timeout are specified in the Annex C 

     (Formal description of MAC operation, see details on the 

     Trsp timer setting at page 346)

  */

  Time ctsTimeout = GetDefaultSifs ();

  ctsTimeout += GetDefaultCtsAckDelay ();

  ctsTimeout += MicroSeconds (GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2);

  ctsTimeout += GetDefaultSlot ();

  return ctsTimeout;

}

TypeId 

WifiMac::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::WifiMac")

    .SetParent<Object> ()

    .AddAttribute ("CtsTimeout", "When this timeout expires, the RTS/CTS handshake has failed.",

                   TimeValue (GetDefaultCtsAckTimeout ()),

                   MakeTimeAccessor (&WifiMac::SetCtsTimeout,

                                     &WifiMac::GetCtsTimeout),

                   MakeTimeChecker ())

    .AddAttribute ("AckTimeout", "When this timeout expires, the DATA/ACK handshake has failed.",

                   TimeValue (GetDefaultCtsAckTimeout ()),

                   MakeTimeAccessor (&WifiMac::GetAckTimeout,

                                     &WifiMac::SetAckTimeout),

                   MakeTimeChecker ())

    .AddAttribute ("Sifs", "The value of the SIFS constant.",

                   TimeValue (GetDefaultSifs ()),

                   MakeTimeAccessor (&WifiMac::SetSifs,

				     &WifiMac::GetSifs),

                   MakeTimeChecker ())

    .AddAttribute ("EifsNoDifs", "The value of EIFS-DIFS",

		   TimeValue (GetDefaultEifsNoDifs ()),

		   MakeTimeAccessor (&WifiMac::SetEifsNoDifs,

				     &WifiMac::GetEifsNoDifs),

		   MakeTimeChecker ())

    .AddAttribute ("Slot", "The duration of a Slot.",

                   TimeValue (GetDefaultSlot ()),

                   MakeTimeAccessor (&WifiMac::SetSlot,

				     &WifiMac::GetSlot),

                   MakeTimeChecker ())

    .AddAttribute ("Pifs", "The value of the PIFS constant.",

                   TimeValue (GetDefaultSifs () + GetDefaultSlot ()),

                   MakeTimeAccessor (&WifiMac::SetPifs,

                                     &WifiMac::GetPifs),

                   MakeTimeChecker ())

    .AddAttribute ("MaxPropagationDelay", "The maximum propagation delay. Unused for now.",

                   TimeValue (GetDefaultMaxPropagationDelay ()),

                   MakeTimeAccessor (&WifiMac::m_maxPropagationDelay),

                   MakeTimeChecker ())

    .AddAttribute ("MaxMsduSize", "The maximum size of an MSDU accepted by the MAC layer."

                   "This value conforms to the specification.",

		   UintegerValue (2304),

		   MakeUintegerAccessor (&WifiMac::m_maxMsduSize),

		   MakeUintegerChecker<uint16_t> (1,2304))

    .AddAttribute ("Ssid", "The ssid we want to belong to.",

		   SsidValue (Ssid ("default")),

		   MakeSsidAccessor (&WifiMac::GetSsid,

				     &WifiMac::SetSsid),

		   MakeSsidChecker ())

    .AddTraceSource ("MacTx", 

                     "A packet has been received from higher layers and is being processed in preparation for "

                     "queueing for transmission.",

                     MakeTraceSourceAccessor (&WifiMac::m_macTxTrace))

    .AddTraceSource ("MacTxDrop", 

                     "A packet has been dropped in the MAC layer before being queued for transmission.",

                     MakeTraceSourceAccessor (&WifiMac::m_macTxDropTrace))

    .AddTraceSource ("MacPromiscRx", 

                     "A packet has been received by this device, has been passed up from the physical layer "

                     "and is being forwarded up the local protocol stack.  This is a promiscuous trace,",

                     MakeTraceSourceAccessor (&WifiMac::m_macPromiscRxTrace))

    .AddTraceSource ("MacRx", 

                     "A packet has been received by this device, has been passed up from the physical layer "

                     "and is being forwarded up the local protocol stack.  This is a non-promiscuous trace,",

                     MakeTraceSourceAccessor (&WifiMac::m_macRxTrace))

    .AddTraceSource ("MacRxDrop", 

                     "A packet has been dropped in the MAC layer after it has been passed up from the physical "

                     "layer.",

                     MakeTraceSourceAccessor (&WifiMac::m_macRxDropTrace))

#if 0

    // Not currently implemented in this device

    .AddTraceSource ("Sniffer", 

                     "Trace source simulating a non-promiscuous packet sniffer attached to the device",

                     MakeTraceSourceAccessor (&WifiMac::m_snifferTrace))

#endif

    ;

  return tid;

}

void 

WifiMac::SetMaxPropagationDelay (Time delay)

{

  m_maxPropagationDelay = delay;

}

Time

WifiMac::GetMsduLifetime (void) const

{

  return Seconds (10);

}

Time

WifiMac::GetMaxPropagationDelay (void) const

{

  return m_maxPropagationDelay;

}

uint32_t 

WifiMac::GetMaxMsduSize (void) const

{

  return m_maxMsduSize;

}

void 

WifiMac::NotifyTx (Ptr<const Packet> packet)

{

  m_macTxTrace (packet);

}

void 

WifiMac::NotifyTxDrop (Ptr<const Packet> packet) 

{

  m_macTxDropTrace (packet);

}

void 

WifiMac::NotifyRx (Ptr<const Packet> packet) 

{

  m_macRxTrace (packet);

}

void 

WifiMac::NotifyPromiscRx (Ptr<const Packet> packet) 

{

  m_macPromiscRxTrace (packet);

}

void 

WifiMac::NotifyRxDrop (Ptr<const Packet> packet) 

{

  m_macRxDropTrace (packet);

}

void

WifiMac::ConfigureStandard (enum WifiPhyStandard standard)

{

  switch (standard) {

  case WIFI_PHY_STANDARD_80211a:

    Configure80211a ();

    break;

  case WIFI_PHY_STANDARD_80211b:

    Configure80211b ();

    break;

  case WIFI_PHY_STANDARD_80211_10Mhz: 

    Configure80211_10Mhz ();

    break;

  case WIFI_PHY_STANDARD_80211_5Mhz:

    Configure80211_5Mhz ();

    break;

  case WIFI_PHY_STANDARD_holland:

    Configure80211a ();

    break;

  case WIFI_PHY_STANDARD_80211p_CCH:

    Configure80211p_CCH ();

    break;

  case WIFI_PHY_STANDARD_80211p_SCH:

    Configure80211p_SCH ();

    break;

  default:

    NS_ASSERT (false);

    break;

  }

  FinishConfigureStandard (standard);

}

void

WifiMac::Configure80211a (void)

{

  SetSifs(MicroSeconds(16));

  SetSlot(MicroSeconds(9)); 

  SetEifsNoDifs(MicroSeconds(16+44));

  SetPifs(MicroSeconds(16+9));

  SetCtsTimeout(MicroSeconds(16+44+9+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(16+44+9+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::Configure80211b (void)

{

  SetSifs(MicroSeconds(10));

  SetSlot(MicroSeconds(20));

  SetEifsNoDifs(MicroSeconds(10+304));

  SetPifs(MicroSeconds(10+20));

  SetCtsTimeout(MicroSeconds(10+304+20+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(10+304+20+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::Configure80211_10Mhz (void)

{

  SetSifs(MicroSeconds(32));

  SetSlot(MicroSeconds(13)); 

  SetEifsNoDifs(MicroSeconds(32+88));

  SetPifs(MicroSeconds(32+13));

  SetCtsTimeout(MicroSeconds(32+88+13+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(32+88+13+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::Configure80211_5Mhz (void)

{

  SetSifs(MicroSeconds(64));

  SetSlot(MicroSeconds(21));

  SetEifsNoDifs(MicroSeconds(64+176));

  SetPifs(MicroSeconds(64+21));

  SetCtsTimeout(MicroSeconds(64+176+21+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(64+176+21+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::Configure80211p_CCH (void)

{

  SetSifs(MicroSeconds(32));

  SetSlot(MicroSeconds(16)); 

  SetEifsNoDifs(MicroSeconds(32+88));

  SetPifs(MicroSeconds(32+16));

  SetCtsTimeout(MicroSeconds(32+88+16+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(32+88+16+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::Configure80211p_SCH (void)

{

  SetSifs(MicroSeconds(32));

  SetSlot(MicroSeconds(16)); 

  SetEifsNoDifs(MicroSeconds(32+88));

  SetPifs(MicroSeconds(32+16));

  SetCtsTimeout(MicroSeconds(32+88+16+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2));

  SetAckTimeout(MicroSeconds(32+88+16+GetDefaultMaxPropagationDelay().GetMicroSeconds ()*2)); 

}

void

WifiMac::ConfigureDcf (Ptr<Dcf> dcf, uint32_t cwmin, uint32_t cwmax, enum AccessClass ac)

{

  /* see IEE802.11 section 7.3.2.29 */

  switch (ac) {

  case AC_VO:

    dcf->SetMinCw ((cwmin+1)/4-1);

    dcf->SetMaxCw ((cwmin+1)/2-1);

    dcf->SetAifsn (2);

    break;

  case AC_VI:

    dcf->SetMinCw ((cwmin+1)/2-1);

    dcf->SetMaxCw (cwmin);

    dcf->SetAifsn (2);

    break;

  case AC_BE:

    dcf->SetMinCw (cwmin);

    dcf->SetMaxCw (cwmax);

    dcf->SetAifsn (3);

    break;

  case AC_BK:

    dcf->SetMinCw (cwmin);

    dcf->SetMaxCw (cwmax);

    dcf->SetAifsn (7);

    break;

  case AC_BE_NQOS:

    dcf->SetMinCw (cwmin);

    dcf->SetMaxCw (cwmax);

    dcf->SetAifsn (2);    

    break;

  case AC_UNDEF:

    NS_FATAL_ERROR ("I don't know what to do with this");

    break;

  }

}

void

WifiMac::ConfigureCCHDcf (Ptr<Dcf> dcf, uint32_t cwmin, uint32_t cwmax, enum AccessClass ac)

{

  /* see IEEE 1609.4-2006 section 6.3.1, Table 1 */

  switch (ac) {

  case AC_VO:

    dcf->SetMinCw ((cwmin+1)/4-1);

    dcf->SetMaxCw ((cwmin+1)/2-1);

    dcf->SetAifsn (2);

    break;

  case AC_VI:

    dcf->SetMinCw ((cwmin+1)/4-1);

    dcf->SetMaxCw ((cwmin+1)/2-1);

    dcf->SetAifsn (3);

    break;

  case AC_BE:

    dcf->SetMinCw ((cwmin+1)/2-1);

    dcf->SetMaxCw (cwmin);

    dcf->SetAifsn (6);

    break;

  case AC_BK:

    dcf->SetMinCw (cwmin);

    dcf->SetMaxCw (cwmax);

    dcf->SetAifsn (9);

    break;

  case AC_BE_NQOS:

    dcf->SetMinCw (cwmin);

    dcf->SetMaxCw (cwmax);

    dcf->SetAifsn (2);    

    break;

  case AC_UNDEF:

    NS_FATAL_ERROR ("I don't know what to do with this");

    break;

  }

}

} // namespace ns3