text: /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
  /*
   * Copyright (c) 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>
   */
  
  #include "ns3/simulator.h"
  #include "ns3/log.h"
  #include "ns3/pointer.h"
  #include "ns3/wifi-net-device.h"
  #include "ns3/node.h"
  #include "ns3/propagation-loss-model.h"
  #include "ns3/propagation-delay-model.h"
  #include "ns3/mobility-model.h"
  #include "yans-wifi-channel.h"
  #include "yans-wifi-phy.h"
  #include "wifi-utils.h"
  #include "wifi-ppdu.h"
  #include "wifi-psdu.h"
  
  namespace ns3 {
  
  NS_LOG_COMPONENT_DEFINE ("YansWifiChannel");
  
  NS_OBJECT_ENSURE_REGISTERED (YansWifiChannel);
  
  TypeId
  YansWifiChannel::GetTypeId (void)
  {
    static TypeId tid = TypeId ("ns3::YansWifiChannel")
      .SetParent<Channel> ()
      .SetGroupName ("Wifi")
      .AddConstructor<YansWifiChannel> ()
      .AddAttribute ("PropagationLossModel", "A pointer to the propagation loss model attached to this channel.",
                     PointerValue (),
                     MakePointerAccessor (&YansWifiChannel::m_loss),
                     MakePointerChecker<PropagationLossModel> ())
      .AddAttribute ("PropagationDelayModel", "A pointer to the propagation delay model attached to this channel.",
                     PointerValue (),
                     MakePointerAccessor (&YansWifiChannel::m_delay),
                     MakePointerChecker<PropagationDelayModel> ())
    ;
    return tid;
  }
  
  YansWifiChannel::YansWifiChannel ()
  {
    NS_LOG_FUNCTION (this);
  }
  
  YansWifiChannel::~YansWifiChannel ()
  {
    NS_LOG_FUNCTION (this);
    m_phyList.clear ();
  }
  
  void
  YansWifiChannel::SetPropagationLossModel (const Ptr<PropagationLossModel> loss)
  {
    NS_LOG_FUNCTION (this << loss);
    m_loss = loss;
  }
  
  void
  YansWifiChannel::SetPropagationDelayModel (const Ptr<PropagationDelayModel> delay)
  {
    NS_LOG_FUNCTION (this << delay);
    m_delay = delay;
  }
  
  void
  YansWifiChannel::Send (Ptr<YansWifiPhy> sender, Ptr<const WifiPpdu> ppdu, double txPowerDbm) const
  {
    NS_LOG_FUNCTION (this << sender << ppdu << txPowerDbm);
    Ptr<MobilityModel> senderMobility = sender->GetMobility ();
    NS_ASSERT (senderMobility != 0);
    for (PhyList::const_iterator i = m_phyList.begin (); i != m_phyList.end (); i++)
      {
        if (sender != (*i))
          {
            //For now don't account for inter channel interference nor channel bonding
            if ((*i)->GetChannelNumber () != sender->GetChannelNumber ())
              {
                continue;
              }
  
            Ptr<MobilityModel> receiverMobility = (*i)->GetMobility ()->GetObject<MobilityModel> ();
            Time delay = m_delay->GetDelay (senderMobility, receiverMobility);
            double rxPowerDbm = m_loss->CalcRxPower (txPowerDbm, senderMobility, receiverMobility);
            NS_LOG_DEBUG ("propagation: txPower=" << txPowerDbm << "dbm, rxPower=" << rxPowerDbm << "dbm, " <<
                          "distance=" << senderMobility->GetDistanceFrom (receiverMobility) << "m, delay=" << delay);
            Ptr<WifiPpdu> copy = ppdu->Copy ();
            Ptr<NetDevice> dstNetDevice = (*i)->GetDevice ();
            uint32_t dstNode;
            if (dstNetDevice == 0)
              {
                dstNode = 0xffffffff;
              }
            else
              {
                dstNode = dstNetDevice->GetNode ()->GetId ();
              }
  
            Simulator::ScheduleWithContext (dstNode,
                                            delay, &YansWifiChannel::Receive,
                                            (*i), copy, rxPowerDbm);
          }
      }
  }
  
  void
  YansWifiChannel::Receive (Ptr<YansWifiPhy> phy, Ptr<WifiPpdu> ppdu, double rxPowerDbm)
  {
    NS_LOG_FUNCTION (phy << ppdu << rxPowerDbm);
    // Do no further processing if signal is too weak
    // Current implementation assumes constant RX power over the PPDU duration
    if ((rxPowerDbm + phy->GetRxGain ()) < phy->GetRxSensitivity ())
      {
        NS_LOG_INFO ("Received signal too weak to process: " << rxPowerDbm << " dBm");
        return;
      }
    RxPowerWattPerChannelBand rxPowerW;
    rxPowerW.insert ({std::make_pair (0, 0), (DbmToW (rxPowerDbm + phy->GetRxGain ()))}); //dummy band for YANS
    phy->StartReceivePreamble (ppdu, rxPowerW, ppdu->GetTxDuration ());
  }
  
  std::size_t
  YansWifiChannel::GetNDevices (void) const
  {
    return m_phyList.size ();
  }
  
  Ptr<NetDevice>
  YansWifiChannel::GetDevice (std::size_t i) const
  {
    return m_phyList[i]->GetDevice ();
  }
  
  void
  YansWifiChannel::Add (Ptr<YansWifiPhy> phy)
  {
    NS_LOG_FUNCTION (this << phy);
    m_phyList.push_back (phy);
  }
  
  int64_t
  YansWifiChannel::AssignStreams (int64_t stream)
  {
    NS_LOG_FUNCTION (this << stream);
    int64_t currentStream = stream;
    currentStream += m_loss->AssignStreams (stream);
    return (currentStream - stream);
  }
  
  } //namespace ns3
  