/* -*- 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 {

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::GetDefaultRifs (void)

{

  //802.11n specific

  return MicroSeconds (2);

}

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;

}

Time

WifiMac::GetDefaultBasicBlockAckDelay (void)

{

  // This value must be rivisited

  return MicroSeconds (250);

}

Time

WifiMac::GetDefaultCompressedBlockAckDelay (void)

{

  // This value must be rivisited was 68. 

 //CompressedBlockAckSize 32* 8*time it takes to transfer at the lowest rate (6Mb/s)+ aPhy-StartDelay(33)

  return MicroSeconds (76);

}

Time

WifiMac::GetDefaultBasicBlockAckTimeout (void)

{

  Time blockAckTimeout = GetDefaultSifs ();

  blockAckTimeout += GetDefaultBasicBlockAckDelay ();

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

  blockAckTimeout += GetDefaultSlot ();

  return blockAckTimeout;

}

Time

WifiMac::GetDefaultCompressedBlockAckTimeout (void)

{

  Time blockAckTimeout = GetDefaultSifs ();

  blockAckTimeout += GetDefaultCompressedBlockAckDelay ();

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

  blockAckTimeout += GetDefaultSlot ();

  return blockAckTimeout;

}

void

WifiMac::SetBasicBlockAckTimeout (Time blockAckTimeout)

{

  //this method must be implemented by QoS WifiMacs

}

Time

WifiMac::GetBasicBlockAckTimeout (void) const

{

  //this method must be implemented by QoS WifiMacs

  return MicroSeconds (0);

}

void

WifiMac::SetCompressedBlockAckTimeout (Time blockAckTimeout)

{

  //this methos must be implemented by QoS WifiMacs

}

Time

WifiMac::GetCompressedBlockAckTimeout (void) const

{

  //this method must be implemented by QoS WifiMacs

  return MicroSeconds (0);

}

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 ("BasicBlockAckTimeout", "When this timeout expires, the BASIC_BLOCK_ACK_REQ/BASIC_BLOCK_ACK handshake has failed.",

                   TimeValue (GetDefaultBasicBlockAckTimeout ()),

                   MakeTimeAccessor (&WifiMac::GetBasicBlockAckTimeout,

                                     &WifiMac::SetBasicBlockAckTimeout),

                   MakeTimeChecker ())

    .AddAttribute ("CompressedBlockAckTimeout", "When this timeout expires, the COMPRESSED_BLOCK_ACK_REQ/COMPRESSED_BLOCK_ACK handshake has failed.",

                   TimeValue (GetDefaultCompressedBlockAckTimeout ()),

                   MakeTimeAccessor (&WifiMac::GetCompressedBlockAckTimeout,

                                     &WifiMac::SetCompressedBlockAckTimeout),

                   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 ("Rifs", "The value of the RIFS constant.",

                   TimeValue (GetDefaultRifs ()),

                   MakeTimeAccessor (&WifiMac::SetRifs,

                                     &WifiMac::GetRifs),

                   MakeTimeChecker ())

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

                   TimeValue (GetDefaultMaxPropagationDelay ()),

                   MakeTimeAccessor (&WifiMac::m_maxPropagationDelay),

                   MakeTimeChecker ())

    .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;

}

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_80211g:

      Configure80211g ();

      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_80211n_2_4GHZ:

      Configure80211n_2_4Ghz ();

      break;

    case WIFI_PHY_STANDARD_80211n_5GHZ:

      Configure80211n_5Ghz ();

      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::Configure80211g (void)

{

  SetSifs (MicroSeconds (10));

  // Note no support for Short Slot Time as yet

  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::Configure80211n_2_4Ghz (void)

{

  Configure80211g ();

  SetRifs(MicroSeconds (2));

  SetCtsTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));

  SetAckTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));

}

void

WifiMac::Configure80211n_5Ghz (void)

{

  Configure80211a ();

  SetRifs(MicroSeconds (2));

  SetCtsTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));

  SetAckTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));

}

void

WifiMac::ConfigureDcf (Ptr<Dcf> dcf, uint32_t cwmin, uint32_t cwmax, enum AcIndex 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;

    }

}

} // namespace ns3