tta-ff-mac-scheduler.cc

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011 Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)
 *
 * 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: Marco Miozzo <marco.miozzo@cttc.es>
 * Modification: Dizhi Zhou <dizhi.zhou@gmail.com>    // modify codes related to downlink scheduler
 */

#include <ns3/log.h>
#include <ns3/pointer.h>
#include <ns3/math.h>

#include <ns3/simulator.h>
#include <ns3/lte-amc.h>
#include <ns3/tta-ff-mac-scheduler.h>
#include <ns3/lte-vendor-specific-parameters.h>
#include <ns3/boolean.h>
#include <set>
#include <cfloat>

NS_LOG_COMPONENT_DEFINE ("TtaFfMacScheduler");

namespace ns3 {

int TtaType0AllocationRbg[4] = {
  10,       // RGB size 1
  26,       // RGB size 2
  63,       // RGB size 3
  110       // RGB size 4
};  // see table 7.1.6.1-1 of 36.213


NS_OBJECT_ENSURE_REGISTERED (TtaFfMacScheduler);



class TtaSchedulerMemberCschedSapProvider : public FfMacCschedSapProvider
{
public:
  TtaSchedulerMemberCschedSapProvider (TtaFfMacScheduler* scheduler);

  // inherited from FfMacCschedSapProvider
  virtual void CschedCellConfigReq (const struct CschedCellConfigReqParameters& params);
  virtual void CschedUeConfigReq (const struct CschedUeConfigReqParameters& params);
  virtual void CschedLcConfigReq (const struct CschedLcConfigReqParameters& params);
  virtual void CschedLcReleaseReq (const struct CschedLcReleaseReqParameters& params);
  virtual void CschedUeReleaseReq (const struct CschedUeReleaseReqParameters& params);

private:
  TtaSchedulerMemberCschedSapProvider ();
  TtaFfMacScheduler* m_scheduler;
};

TtaSchedulerMemberCschedSapProvider::TtaSchedulerMemberCschedSapProvider ()
{
}

TtaSchedulerMemberCschedSapProvider::TtaSchedulerMemberCschedSapProvider (TtaFfMacScheduler* scheduler) : m_scheduler (scheduler)
{
}


void
TtaSchedulerMemberCschedSapProvider::CschedCellConfigReq (const struct CschedCellConfigReqParameters& params)
{
  m_scheduler->DoCschedCellConfigReq (params);
}

void
TtaSchedulerMemberCschedSapProvider::CschedUeConfigReq (const struct CschedUeConfigReqParameters& params)
{
  m_scheduler->DoCschedUeConfigReq (params);
}


void
TtaSchedulerMemberCschedSapProvider::CschedLcConfigReq (const struct CschedLcConfigReqParameters& params)
{
  m_scheduler->DoCschedLcConfigReq (params);
}

void
TtaSchedulerMemberCschedSapProvider::CschedLcReleaseReq (const struct CschedLcReleaseReqParameters& params)
{
  m_scheduler->DoCschedLcReleaseReq (params);
}

void
TtaSchedulerMemberCschedSapProvider::CschedUeReleaseReq (const struct CschedUeReleaseReqParameters& params)
{
  m_scheduler->DoCschedUeReleaseReq (params);
}




class TtaSchedulerMemberSchedSapProvider : public FfMacSchedSapProvider
{
public:
  TtaSchedulerMemberSchedSapProvider (TtaFfMacScheduler* scheduler);

  // inherited from FfMacSchedSapProvider
  virtual void SchedDlRlcBufferReq (const struct SchedDlRlcBufferReqParameters& params);
  virtual void SchedDlPagingBufferReq (const struct SchedDlPagingBufferReqParameters& params);
  virtual void SchedDlMacBufferReq (const struct SchedDlMacBufferReqParameters& params);
  virtual void SchedDlTriggerReq (const struct SchedDlTriggerReqParameters& params);
  virtual void SchedDlRachInfoReq (const struct SchedDlRachInfoReqParameters& params);
  virtual void SchedDlCqiInfoReq (const struct SchedDlCqiInfoReqParameters& params);
  virtual void SchedUlTriggerReq (const struct SchedUlTriggerReqParameters& params);
  virtual void SchedUlNoiseInterferenceReq (const struct SchedUlNoiseInterferenceReqParameters& params);
  virtual void SchedUlSrInfoReq (const struct SchedUlSrInfoReqParameters& params);
  virtual void SchedUlMacCtrlInfoReq (const struct SchedUlMacCtrlInfoReqParameters& params);
  virtual void SchedUlCqiInfoReq (const struct SchedUlCqiInfoReqParameters& params);


private:
  TtaSchedulerMemberSchedSapProvider ();
  TtaFfMacScheduler* m_scheduler;
};



TtaSchedulerMemberSchedSapProvider::TtaSchedulerMemberSchedSapProvider ()
{
}


TtaSchedulerMemberSchedSapProvider::TtaSchedulerMemberSchedSapProvider (TtaFfMacScheduler* scheduler)
  : m_scheduler (scheduler)
{
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlRlcBufferReq (const struct SchedDlRlcBufferReqParameters& params)
{
  m_scheduler->DoSchedDlRlcBufferReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlPagingBufferReq (const struct SchedDlPagingBufferReqParameters& params)
{
  m_scheduler->DoSchedDlPagingBufferReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlMacBufferReq (const struct SchedDlMacBufferReqParameters& params)
{
  m_scheduler->DoSchedDlMacBufferReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlTriggerReq (const struct SchedDlTriggerReqParameters& params)
{
  m_scheduler->DoSchedDlTriggerReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlRachInfoReq (const struct SchedDlRachInfoReqParameters& params)
{
  m_scheduler->DoSchedDlRachInfoReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedDlCqiInfoReq (const struct SchedDlCqiInfoReqParameters& params)
{
  m_scheduler->DoSchedDlCqiInfoReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedUlTriggerReq (const struct SchedUlTriggerReqParameters& params)
{
  m_scheduler->DoSchedUlTriggerReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedUlNoiseInterferenceReq (const struct SchedUlNoiseInterferenceReqParameters& params)
{
  m_scheduler->DoSchedUlNoiseInterferenceReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedUlSrInfoReq (const struct SchedUlSrInfoReqParameters& params)
{
  m_scheduler->DoSchedUlSrInfoReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedUlMacCtrlInfoReq (const struct SchedUlMacCtrlInfoReqParameters& params)
{
  m_scheduler->DoSchedUlMacCtrlInfoReq (params);
}

void
TtaSchedulerMemberSchedSapProvider::SchedUlCqiInfoReq (const struct SchedUlCqiInfoReqParameters& params)
{
  m_scheduler->DoSchedUlCqiInfoReq (params);
}





TtaFfMacScheduler::TtaFfMacScheduler ()
  :   m_cschedSapUser (0),
    m_schedSapUser (0),
    m_nextRntiUl (0)
{
  m_amc = CreateObject <LteAmc> ();
  m_cschedSapProvider = new TtaSchedulerMemberCschedSapProvider (this);
  m_schedSapProvider = new TtaSchedulerMemberSchedSapProvider (this);
}

TtaFfMacScheduler::~TtaFfMacScheduler ()
{
  NS_LOG_FUNCTION (this);
}

void
TtaFfMacScheduler::DoDispose ()
{
  NS_LOG_FUNCTION (this);
  m_dlHarqProcessesDciBuffer.clear ();
  m_dlHarqProcessesTimer.clear ();
  m_dlHarqProcessesRlcPduListBuffer.clear ();
  m_dlInfoListBuffered.clear ();
  m_ulHarqCurrentProcessId.clear ();
  m_ulHarqProcessesStatus.clear ();
  m_ulHarqProcessesDciBuffer.clear ();
  delete m_cschedSapProvider;
  delete m_schedSapProvider;
}

TypeId
TtaFfMacScheduler::GetTypeId (void)
{
  static TypeId tid = TypeId ("ns3::TtaFfMacScheduler")
    .SetParent<FfMacScheduler> ()
    .AddConstructor<TtaFfMacScheduler> ()
    .AddAttribute ("CqiTimerThreshold",
                   "The number of TTIs a CQI is valid (default 1000 - 1 sec.)",
                   UintegerValue (1000),
                   MakeUintegerAccessor (&TtaFfMacScheduler::m_cqiTimersThreshold),
                   MakeUintegerChecker<uint32_t> ())
    .AddAttribute ("HarqEnabled",
                   "Activate/Deactivate the HARQ [by default is active].",
                   BooleanValue (true),
                   MakeBooleanAccessor (&TtaFfMacScheduler::m_harqOn),
                   MakeBooleanChecker ())
    .AddAttribute ("UlGrantMcs",
                   "The MCS of the UL grant, must be [0..15] (default 0)",
                   UintegerValue (0),
                   MakeUintegerAccessor (&TtaFfMacScheduler::m_ulGrantMcs),
                   MakeUintegerChecker<uint8_t> ())
  ;
  return tid;
}



void
TtaFfMacScheduler::SetFfMacCschedSapUser (FfMacCschedSapUser* s)
{
  m_cschedSapUser = s;
}

void
TtaFfMacScheduler::SetFfMacSchedSapUser (FfMacSchedSapUser* s)
{
  m_schedSapUser = s;
}

FfMacCschedSapProvider*
TtaFfMacScheduler::GetFfMacCschedSapProvider ()
{
  return m_cschedSapProvider;
}

FfMacSchedSapProvider*
TtaFfMacScheduler::GetFfMacSchedSapProvider ()
{
  return m_schedSapProvider;
}

void
TtaFfMacScheduler::DoCschedCellConfigReq (const struct FfMacCschedSapProvider::CschedCellConfigReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  // Read the subset of parameters used
  m_cschedCellConfig = params;
  m_rachAllocationMap.resize (m_cschedCellConfig.m_ulBandwidth, 0);
  FfMacCschedSapUser::CschedUeConfigCnfParameters cnf;
  cnf.m_result = SUCCESS;
  m_cschedSapUser->CschedUeConfigCnf (cnf);
  return;
}

void
TtaFfMacScheduler::DoCschedUeConfigReq (const struct FfMacCschedSapProvider::CschedUeConfigReqParameters& params)
{
  NS_LOG_FUNCTION (this << " RNTI " << params.m_rnti << " txMode " << (uint16_t)params.m_transmissionMode);
  std::map <uint16_t,uint8_t>::iterator it = m_uesTxMode.find (params.m_rnti);
  if (it == m_uesTxMode.end ())
    {
      m_uesTxMode.insert (std::pair <uint16_t, double> (params.m_rnti, params.m_transmissionMode));
      // generate HARQ buffers
      m_dlHarqCurrentProcessId.insert (std::pair <uint16_t,uint8_t > (params.m_rnti, 0));
      DlHarqProcessesStatus_t dlHarqPrcStatus;
      dlHarqPrcStatus.resize (8,0);
      m_dlHarqProcessesStatus.insert (std::pair <uint16_t, DlHarqProcessesStatus_t> (params.m_rnti, dlHarqPrcStatus));
      DlHarqProcessesTimer_t dlHarqProcessesTimer;
      dlHarqProcessesTimer.resize (8,0);
      m_dlHarqProcessesTimer.insert (std::pair <uint16_t, DlHarqProcessesTimer_t> (params.m_rnti, dlHarqProcessesTimer));
      DlHarqProcessesDciBuffer_t dlHarqdci;
      dlHarqdci.resize (8);
      m_dlHarqProcessesDciBuffer.insert (std::pair <uint16_t, DlHarqProcessesDciBuffer_t> (params.m_rnti, dlHarqdci));
      DlHarqRlcPduListBuffer_t dlHarqRlcPdu;
      dlHarqRlcPdu.resize (2);
      dlHarqRlcPdu.at (0).resize (8);
      dlHarqRlcPdu.at (1).resize (8);
      m_dlHarqProcessesRlcPduListBuffer.insert (std::pair <uint16_t, DlHarqRlcPduListBuffer_t> (params.m_rnti, dlHarqRlcPdu));
      m_ulHarqCurrentProcessId.insert (std::pair <uint16_t,uint8_t > (params.m_rnti, 0));
      UlHarqProcessesStatus_t ulHarqPrcStatus;
      ulHarqPrcStatus.resize (8,0);
      m_ulHarqProcessesStatus.insert (std::pair <uint16_t, UlHarqProcessesStatus_t> (params.m_rnti, ulHarqPrcStatus));
      UlHarqProcessesDciBuffer_t ulHarqdci;
      ulHarqdci.resize (8);
      m_ulHarqProcessesDciBuffer.insert (std::pair <uint16_t, UlHarqProcessesDciBuffer_t> (params.m_rnti, ulHarqdci));
    }
  else
    {
      (*it).second = params.m_transmissionMode;
    }
  return;
}

void
TtaFfMacScheduler::DoCschedLcConfigReq (const struct FfMacCschedSapProvider::CschedLcConfigReqParameters& params)
{
  NS_LOG_FUNCTION (this << " New LC, rnti: "  << params.m_rnti);

  std::set <uint16_t>::iterator it;
  for (uint16_t i = 0; i < params.m_logicalChannelConfigList.size (); i++)
    {
      it = m_flowStatsDl.find (params.m_rnti);

      if (it == m_flowStatsDl.end ())
        {
          m_flowStatsDl.insert (params.m_rnti);
          m_flowStatsUl.insert (params.m_rnti);
        }
    }

  return;
}

void
TtaFfMacScheduler::DoCschedLcReleaseReq (const struct FfMacCschedSapProvider::CschedLcReleaseReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  for (uint16_t i = 0; i < params.m_logicalChannelIdentity.size (); i++)
    {
      std::map<LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it = m_rlcBufferReq.begin ();
      std::map<LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator temp;
      while (it!=m_rlcBufferReq.end ())
        {
          if (((*it).first.m_rnti == params.m_rnti) && ((*it).first.m_lcId == params.m_logicalChannelIdentity.at (i)))
            {
              temp = it;
              it++;
              m_rlcBufferReq.erase (temp);
            }
          else
            {
              it++;
            }
        }
    }
  return;
}

void
TtaFfMacScheduler::DoCschedUeReleaseReq (const struct FfMacCschedSapProvider::CschedUeReleaseReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  
  m_uesTxMode.erase (params.m_rnti);
  m_dlHarqCurrentProcessId.erase (params.m_rnti);
  m_dlHarqProcessesStatus.erase  (params.m_rnti);
  m_dlHarqProcessesTimer.erase (params.m_rnti);
  m_dlHarqProcessesDciBuffer.erase  (params.m_rnti);
  m_dlHarqProcessesRlcPduListBuffer.erase  (params.m_rnti);
  m_ulHarqCurrentProcessId.erase  (params.m_rnti);
  m_ulHarqProcessesStatus.erase  (params.m_rnti);
  m_ulHarqProcessesDciBuffer.erase  (params.m_rnti);
  m_flowStatsDl.erase  (params.m_rnti);
  m_flowStatsUl.erase  (params.m_rnti);
  m_ceBsrRxed.erase (params.m_rnti);
  std::map<LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it = m_rlcBufferReq.begin ();
  std::map<LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator temp;
  while (it!=m_rlcBufferReq.end ())
    {
      if ((*it).first.m_rnti == params.m_rnti)
        {
          temp = it;
          it++;
          m_rlcBufferReq.erase (temp);
        }
      else
        {
          it++;
        }
    }
  if (m_nextRntiUl == params.m_rnti)
    {
      m_nextRntiUl = 0;
    }

  return;
}


void
TtaFfMacScheduler::DoSchedDlRlcBufferReq (const struct FfMacSchedSapProvider::SchedDlRlcBufferReqParameters& params)
{
  NS_LOG_FUNCTION (this << params.m_rnti << (uint32_t) params.m_logicalChannelIdentity);
  // API generated by RLC for updating RLC parameters on a LC (tx and retx queues)

  std::map <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;

  LteFlowId_t flow (params.m_rnti, params.m_logicalChannelIdentity);

  it =  m_rlcBufferReq.find (flow);

  if (it == m_rlcBufferReq.end ())
    {
      m_rlcBufferReq.insert (std::pair <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters> (flow, params));
    }
  else
    {
      (*it).second = params;
    }

  return;
}

void
TtaFfMacScheduler::DoSchedDlPagingBufferReq (const struct FfMacSchedSapProvider::SchedDlPagingBufferReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  NS_FATAL_ERROR ("method not implemented");
  return;
}

void
TtaFfMacScheduler::DoSchedDlMacBufferReq (const struct FfMacSchedSapProvider::SchedDlMacBufferReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  NS_FATAL_ERROR ("method not implemented");
  return;
}

int
TtaFfMacScheduler::GetRbgSize (int dlbandwidth)
{
  for (int i = 0; i < 4; i++)
    {
      if (dlbandwidth < TtaType0AllocationRbg[i])
        {
          return (i + 1);
        }
    }

  return (-1);
}


int
TtaFfMacScheduler::LcActivePerFlow (uint16_t rnti)
{
  std::map <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;
  int lcActive = 0;
  for (it = m_rlcBufferReq.begin (); it != m_rlcBufferReq.end (); it++)
    {
      if (((*it).first.m_rnti == rnti) && (((*it).second.m_rlcTransmissionQueueSize > 0)
                                           || ((*it).second.m_rlcRetransmissionQueueSize > 0)
                                           || ((*it).second.m_rlcStatusPduSize > 0) ))
        {
          lcActive++;
        }
      if ((*it).first.m_rnti > rnti)
        {
          break;
        }
    }
  return (lcActive);

}


uint8_t
TtaFfMacScheduler::HarqProcessAvailability (uint16_t rnti)
{
  NS_LOG_FUNCTION (this << rnti);

  std::map <uint16_t, uint8_t>::iterator it = m_dlHarqCurrentProcessId.find (rnti);
  if (it == m_dlHarqCurrentProcessId.end ())
    {
      NS_FATAL_ERROR ("No Process Id found for this RNTI " << rnti);
    }
  std::map <uint16_t, DlHarqProcessesStatus_t>::iterator itStat = m_dlHarqProcessesStatus.find (rnti);
  if (itStat == m_dlHarqProcessesStatus.end ())
    {
      NS_FATAL_ERROR ("No Process Id Statusfound for this RNTI " << rnti);
    }
  uint8_t i = (*it).second;
  do
    {
      i = (i + 1) % HARQ_PROC_NUM;
    }
  while ( ((*itStat).second.at (i) != 0)&&(i != (*it).second));
  if ((*itStat).second.at (i) == 0)
    {
      return (true);
    }
  else
    {
      return (false); // return a not valid harq proc id
    }
}



uint8_t
TtaFfMacScheduler::UpdateHarqProcessId (uint16_t rnti)
{
  NS_LOG_FUNCTION (this << rnti);

  if (m_harqOn == false)
    {
      return (0);
    }


  std::map <uint16_t, uint8_t>::iterator it = m_dlHarqCurrentProcessId.find (rnti);
  if (it == m_dlHarqCurrentProcessId.end ())
    {
      NS_FATAL_ERROR ("No Process Id found for this RNTI " << rnti);
    }
  std::map <uint16_t, DlHarqProcessesStatus_t>::iterator itStat = m_dlHarqProcessesStatus.find (rnti);
  if (itStat == m_dlHarqProcessesStatus.end ())
    {
      NS_FATAL_ERROR ("No Process Id Statusfound for this RNTI " << rnti);
    }
  uint8_t i = (*it).second;
  do
    {
      i = (i + 1) % HARQ_PROC_NUM;
    }
  while ( ((*itStat).second.at (i) != 0)&&(i != (*it).second));
  if ((*itStat).second.at (i) == 0)
    {
      (*it).second = i;
      (*itStat).second.at (i) = 1;
    }
  else
    {
      NS_FATAL_ERROR ("No HARQ process available for RNTI " << rnti << " check before update with HarqProcessAvailability");
    }

  return ((*it).second);
}


void
TtaFfMacScheduler::RefreshHarqProcesses ()
{
  NS_LOG_FUNCTION (this);

  std::map <uint16_t, DlHarqProcessesTimer_t>::iterator itTimers;
  for (itTimers = m_dlHarqProcessesTimer.begin (); itTimers != m_dlHarqProcessesTimer.end (); itTimers ++)
    {
      for (uint16_t i = 0; i < HARQ_PROC_NUM; i++)
        {
          if ((*itTimers).second.at (i) == HARQ_DL_TIMEOUT)
            {
              // reset HARQ process
              
              NS_LOG_DEBUG (this << " Reset HARQ proc " << i << " for RNTI " << (*itTimers).first);
              std::map <uint16_t, DlHarqProcessesStatus_t>::iterator itStat = m_dlHarqProcessesStatus.find ((*itTimers).first);
              if (itStat == m_dlHarqProcessesStatus.end ())
                {
                  NS_FATAL_ERROR ("No Process Id Status found for this RNTI " << (*itTimers).first);
                }
              (*itStat).second.at (i) = 0;
              (*itTimers).second.at (i) = 0;
            }
          else
            {
              (*itTimers).second.at (i)++;
            }
        }
    }
  
}


void
TtaFfMacScheduler::DoSchedDlTriggerReq (const struct FfMacSchedSapProvider::SchedDlTriggerReqParameters& params)
{
  NS_LOG_FUNCTION (this << " Frame no. " << (params.m_sfnSf >> 4) << " subframe no. " << (0xF & params.m_sfnSf));
  // API generated by RLC for triggering the scheduling of a DL subframe


  // evaluate the relative channel quality indicator for each UE per each RBG
  // (since we are using allocation type 0 the small unit of allocation is RBG)
  // Resource allocation type 0 (see sec 7.1.6.1 of 36.213)

  RefreshDlCqiMaps ();

  int rbgSize = GetRbgSize (m_cschedCellConfig.m_dlBandwidth);
  int rbgNum = m_cschedCellConfig.m_dlBandwidth / rbgSize;
  std::map <uint16_t, std::vector <uint16_t> > allocationMap; // RBs map per RNTI
  std::vector <bool> rbgMap;  // global RBGs map
  uint16_t rbgAllocatedNum = 0;
  std::set <uint16_t> rntiAllocated;
  rbgMap.resize (m_cschedCellConfig.m_dlBandwidth / rbgSize, false);
  FfMacSchedSapUser::SchedDlConfigIndParameters ret;

  // RACH Allocation
  m_rachAllocationMap.resize (m_cschedCellConfig.m_ulBandwidth, 0);
  uint16_t rbStart = 0;
  std::vector <struct RachListElement_s>::iterator itRach;
  for (itRach = m_rachList.begin (); itRach != m_rachList.end (); itRach++)
    {
      NS_ASSERT_MSG (m_amc->GetTbSizeFromMcs (m_ulGrantMcs, m_cschedCellConfig.m_ulBandwidth) > (*itRach).m_estimatedSize, " Default UL Grant MCS does not allow to send RACH messages");
      BuildRarListElement_s newRar;
      newRar.m_rnti = (*itRach).m_rnti;
      // DL-RACH Allocation
      // Ideal: no needs of configuring m_dci
      // UL-RACH Allocation
      newRar.m_grant.m_rnti = newRar.m_rnti;
      newRar.m_grant.m_mcs = m_ulGrantMcs;
      uint16_t rbLen = 1;
      uint16_t tbSizeBits = 0;
      // find lowest TB size that fits UL grant estimated size
      while ((tbSizeBits < (*itRach).m_estimatedSize) && (rbStart + rbLen < m_cschedCellConfig.m_ulBandwidth))
        {
          rbLen++;
          tbSizeBits = m_amc->GetTbSizeFromMcs (m_ulGrantMcs, rbLen);
        }
      if (tbSizeBits < (*itRach).m_estimatedSize)
        {
          // no more allocation space: finish allocation
          break;
        }
      newRar.m_grant.m_rbStart = rbStart;
      newRar.m_grant.m_rbLen = rbLen;
      newRar.m_grant.m_tbSize = tbSizeBits / 8;
      newRar.m_grant.m_hopping = false;
      newRar.m_grant.m_tpc = 0;
      newRar.m_grant.m_cqiRequest = false;
      newRar.m_grant.m_ulDelay = false;
      NS_LOG_INFO (this << " UL grant allocated to RNTI " << (*itRach).m_rnti << " rbStart " << rbStart << " rbLen " << rbLen << " MCS " << m_ulGrantMcs << " tbSize " << newRar.m_grant.m_tbSize);
      for (uint16_t i = rbStart; i < rbStart + rbLen; i++)
        {
          m_rachAllocationMap.at (i) = (*itRach).m_rnti;
        }
      rbStart = rbStart + rbLen;

      ret.m_buildRarList.push_back (newRar);
    }
  m_rachList.clear ();


  // Process DL HARQ feedback
  RefreshHarqProcesses ();
  // retrieve past HARQ retx buffered
  if (m_dlInfoListBuffered.size () > 0)
    {
      if (params.m_dlInfoList.size () > 0)
        {
          NS_LOG_INFO (this << " Received DL-HARQ feedback");
          m_dlInfoListBuffered.insert (m_dlInfoListBuffered.end (), params.m_dlInfoList.begin (), params.m_dlInfoList.end ());
        }
    }
  else
    {
      if (params.m_dlInfoList.size () > 0)
        {
          m_dlInfoListBuffered = params.m_dlInfoList;
        }
    }
  if (m_harqOn == false)
    {
      // Ignore HARQ feedback
      m_dlInfoListBuffered.clear ();
    }
  std::vector <struct DlInfoListElement_s> dlInfoListUntxed;
  for (uint16_t i = 0; i < m_dlInfoListBuffered.size (); i++)
    {
      std::set <uint16_t>::iterator itRnti = rntiAllocated.find (m_dlInfoListBuffered.at (i).m_rnti);
      if (itRnti != rntiAllocated.end ())
        {
          // RNTI already allocated for retx
          continue;
        }
      uint8_t nLayers = m_dlInfoListBuffered.at (i).m_harqStatus.size ();
      std::vector <bool> retx;
      NS_LOG_INFO (this << " Processing DLHARQ feedback");
      if (nLayers == 1)
        {
          retx.push_back (m_dlInfoListBuffered.at (i).m_harqStatus.at (0) == DlInfoListElement_s::NACK);
          retx.push_back (false);
        }
      else
        {
          retx.push_back (m_dlInfoListBuffered.at (i).m_harqStatus.at (0) == DlInfoListElement_s::NACK);
          retx.push_back (m_dlInfoListBuffered.at (i).m_harqStatus.at (1) == DlInfoListElement_s::NACK);
        }
      if (retx.at (0) || retx.at (1))
        {
          // retrieve HARQ process information
          uint16_t rnti = m_dlInfoListBuffered.at (i).m_rnti;
          uint8_t harqId = m_dlInfoListBuffered.at (i).m_harqProcessId;
          NS_LOG_INFO (this << " HARQ retx RNTI " << rnti << " harqId " << (uint16_t)harqId);
          std::map <uint16_t, DlHarqProcessesDciBuffer_t>::iterator itHarq = m_dlHarqProcessesDciBuffer.find (rnti);
          if (itHarq == m_dlHarqProcessesDciBuffer.end ())
            {
              NS_FATAL_ERROR ("No info find in HARQ buffer for UE " << rnti);
            }

          DlDciListElement_s dci = (*itHarq).second.at (harqId);
          int rv = 0;
          if (dci.m_rv.size () == 1)
            {
              rv = dci.m_rv.at (0);
            }
          else
            {
              rv = (dci.m_rv.at (0) > dci.m_rv.at (1) ? dci.m_rv.at (0) : dci.m_rv.at (1));
            }

          if (rv == 3)
            {
              // maximum number of retx reached -> drop process
              NS_LOG_INFO ("Maximum number of retransmissions reached -> drop process");
              std::map <uint16_t, DlHarqProcessesStatus_t>::iterator it = m_dlHarqProcessesStatus.find (rnti);
              if (it == m_dlHarqProcessesStatus.end ())
                {
                  NS_LOG_ERROR ("No info find in HARQ buffer for UE (might change eNB) " << m_dlInfoListBuffered.at (i).m_rnti);
                }
              (*it).second.at (harqId) = 0;
              std::map <uint16_t, DlHarqRlcPduListBuffer_t>::iterator itRlcPdu =  m_dlHarqProcessesRlcPduListBuffer.find (rnti);
              if (itRlcPdu == m_dlHarqProcessesRlcPduListBuffer.end ())
                {
                  NS_FATAL_ERROR ("Unable to find RlcPdcList in HARQ buffer for RNTI " << m_dlInfoListBuffered.at (i).m_rnti);
                }
              for (uint16_t k = 0; k < (*itRlcPdu).second.size (); k++)
                {
                  (*itRlcPdu).second.at (k).at (harqId).clear ();
                }
              continue;
            }
          // check the feasibility of retransmitting on the same RBGs
          // translate the DCI to Spectrum framework
          std::vector <int> dciRbg;
          uint32_t mask = 0x1;
          NS_LOG_INFO ("Original RBGs " << dci.m_rbBitmap << " rnti " << dci.m_rnti);
          for (int j = 0; j < 32; j++)
            {
              if (((dci.m_rbBitmap & mask) >> j) == 1)
                {
                  dciRbg.push_back (j);
                  NS_LOG_INFO ("\t" << j);
                }
              mask = (mask << 1);
            }
          bool free = true;
          for (uint8_t j = 0; j < dciRbg.size (); j++)
            {
              if (rbgMap.at (dciRbg.at (j)) == true)
                {
                  free = false;
                  break;
                }
            }
          if (free)
            {
              // use the same RBGs for the retx
              // reserve RBGs
              for (uint8_t j = 0; j < dciRbg.size (); j++)
                {
                  rbgMap.at (dciRbg.at (j)) = true;
                  NS_LOG_INFO ("RBG " << dciRbg.at (j) << " assigned");
                  rbgAllocatedNum++;
                }

              NS_LOG_INFO (this << " Send retx in the same RBGs");
            }
          else
            {
              // find RBGs for sending HARQ retx
              uint8_t j = 0;
              uint8_t rbgId = (dciRbg.at (dciRbg.size () - 1) + 1) % rbgNum;
              uint8_t startRbg = dciRbg.at (dciRbg.size () - 1);
              std::vector <bool> rbgMapCopy = rbgMap;
              while ((j < dciRbg.size ())&&(startRbg != rbgId))
                {
                  if (rbgMapCopy.at (rbgId) == false)
                    {
                      rbgMapCopy.at (rbgId) = true;
                      dciRbg.at (j) = rbgId;
                      j++;
                    }
                  rbgId++;
                }
              if (j == dciRbg.size ())
                {
                  // find new RBGs -> update DCI map
                  uint32_t rbgMask = 0;
                  for (uint16_t k = 0; k < dciRbg.size (); k++)
                    {
                      rbgMask = rbgMask + (0x1 << dciRbg.at (k));
                      rbgAllocatedNum++;
                    }
                  dci.m_rbBitmap = rbgMask;
                  rbgMap = rbgMapCopy;
                  NS_LOG_INFO (this << " Move retx in RBGs " << dciRbg.size ());
                }
              else
                {
                  // HARQ retx cannot be performed on this TTI -> store it
                  dlInfoListUntxed.push_back (params.m_dlInfoList.at (i));
                  NS_LOG_INFO (this << " No resource for this retx -> buffer it");
                }
            }
          // retrieve RLC PDU list for retx TBsize and update DCI
          BuildDataListElement_s newEl;
          std::map <uint16_t, DlHarqRlcPduListBuffer_t>::iterator itRlcPdu =  m_dlHarqProcessesRlcPduListBuffer.find (rnti);
          if (itRlcPdu == m_dlHarqProcessesRlcPduListBuffer.end ())
            {
              NS_FATAL_ERROR ("Unable to find RlcPdcList in HARQ buffer for RNTI " << rnti);
            }
          for (uint8_t j = 0; j < nLayers; j++)
            {
              if (retx.at (j))
                {
                  if (j >= dci.m_ndi.size ())
                    {
                      // for avoiding errors in MIMO transient phases
                      dci.m_ndi.push_back (0);
                      dci.m_rv.push_back (0);
                      dci.m_mcs.push_back (0);
                      dci.m_tbsSize.push_back (0);
                      NS_LOG_INFO (this << " layer " << (uint16_t)j << " no txed (MIMO transition)");
                    }
                  else
                    {
                      dci.m_ndi.at (j) = 0;
                      dci.m_rv.at (j)++;
                      (*itHarq).second.at (harqId).m_rv.at (j)++;
                      NS_LOG_INFO (this << " layer " << (uint16_t)j << " RV " << (uint16_t)dci.m_rv.at (j));
                    }
                }
              else
                {
                  // empty TB of layer j
                  dci.m_ndi.at (j) = 0;
                  dci.m_rv.at (j) = 0;
                  dci.m_mcs.at (j) = 0;
                  dci.m_tbsSize.at (j) = 0;
                  NS_LOG_INFO (this << " layer " << (uint16_t)j << " no retx");
                }
            }
          for (uint16_t k = 0; k < (*itRlcPdu).second.at (0).at (dci.m_harqProcess).size (); k++)
            {
              std::vector <struct RlcPduListElement_s> rlcPduListPerLc;
              for (uint8_t j = 0; j < nLayers; j++)
                {
                  if (retx.at (j))
                    {
                      if (j < dci.m_ndi.size ())
                        {
                          rlcPduListPerLc.push_back ((*itRlcPdu).second.at (j).at (dci.m_harqProcess).at (k));
                        }
                    }
                }

              if (rlcPduListPerLc.size () > 0)
                {
                  newEl.m_rlcPduList.push_back (rlcPduListPerLc);
                }
            }
          newEl.m_rnti = rnti;
          newEl.m_dci = dci;
          (*itHarq).second.at (harqId).m_rv = dci.m_rv;
          // refresh timer
          std::map <uint16_t, DlHarqProcessesTimer_t>::iterator itHarqTimer = m_dlHarqProcessesTimer.find (rnti);
          if (itHarqTimer== m_dlHarqProcessesTimer.end ())
            {
              NS_FATAL_ERROR ("Unable to find HARQ timer for RNTI " << (uint16_t)rnti);
            }
          (*itHarqTimer).second.at (harqId) = 0;
          ret.m_buildDataList.push_back (newEl);
          rntiAllocated.insert (rnti);
        }
      else
        {
          // update HARQ process status
          NS_LOG_INFO (this << " HARQ received ACK for UE " << m_dlInfoListBuffered.at (i).m_rnti);
          std::map <uint16_t, DlHarqProcessesStatus_t>::iterator it = m_dlHarqProcessesStatus.find (m_dlInfoListBuffered.at (i).m_rnti);
          if (it == m_dlHarqProcessesStatus.end ())
            {
              NS_FATAL_ERROR ("No info find in HARQ buffer for UE " << m_dlInfoListBuffered.at (i).m_rnti);
            }
          (*it).second.at (m_dlInfoListBuffered.at (i).m_harqProcessId) = 0;
          std::map <uint16_t, DlHarqRlcPduListBuffer_t>::iterator itRlcPdu =  m_dlHarqProcessesRlcPduListBuffer.find (m_dlInfoListBuffered.at (i).m_rnti);
          if (itRlcPdu == m_dlHarqProcessesRlcPduListBuffer.end ())
            {
              NS_FATAL_ERROR ("Unable to find RlcPdcList in HARQ buffer for RNTI " << m_dlInfoListBuffered.at (i).m_rnti);
            }
          for (uint16_t k = 0; k < (*itRlcPdu).second.size (); k++)
            {
              (*itRlcPdu).second.at (k).at (m_dlInfoListBuffered.at (i).m_harqProcessId).clear ();
            }
        }
    }
  m_dlInfoListBuffered.clear ();
  m_dlInfoListBuffered = dlInfoListUntxed;



  for (int i = 0; i < rbgNum; i++)
    {
      NS_LOG_INFO (this << " ALLOCATION for RBG " << i << " of " << rbgNum);
      if (rbgMap.at (i) == false)
        {
          std::set <uint16_t>::iterator it;
          std::set <uint16_t>::iterator itMax = m_flowStatsDl.end ();
          double rcqiMax = 0.0;
          for (it = m_flowStatsDl.begin (); it != m_flowStatsDl.end (); it++)
            {
              std::set <uint16_t>::iterator itRnti = rntiAllocated.find ((*it));
              if ((itRnti != rntiAllocated.end ())||(!HarqProcessAvailability ((*it))))
                {
                  // UE already allocated for HARQ or without HARQ process available -> drop it
                  if (itRnti != rntiAllocated.end ())
                  {
                    NS_LOG_DEBUG (this << " RNTI discared for HARQ tx" << (uint16_t)(*it));
                  }
                  if (!HarqProcessAvailability ((*it)))
                  {
                    NS_LOG_DEBUG (this << " RNTI discared for HARQ id" << (uint16_t)(*it));
                  }
                  continue;
                }

              std::map <uint16_t,SbMeasResult_s>::iterator itSbCqi;
              itSbCqi = m_a30CqiRxed.find ((*it));
              std::map <uint16_t,uint8_t>::iterator itWbCqi;
              itWbCqi = m_p10CqiRxed.find ((*it));

              std::map <uint16_t,uint8_t>::iterator itTxMode;
              itTxMode = m_uesTxMode.find ((*it));
              if (itTxMode == m_uesTxMode.end ())
                {
                  NS_FATAL_ERROR ("No Transmission Mode info on user " << (*it));
                }
              int nLayer = TransmissionModesLayers::TxMode2LayerNum ((*itTxMode).second);

              std::vector <uint8_t> sbCqi;
              if (itSbCqi == m_a30CqiRxed.end ())
                {
                  for (uint8_t k = 0; k < nLayer; k++)
                    {
                      sbCqi.push_back (1);  // start with lowest value
                    }
                }
              else
                {
                  sbCqi = (*itSbCqi).second.m_higherLayerSelected.at (i).m_sbCqi;
                }

              uint8_t wbCqi = 0;
              if (itWbCqi != m_p10CqiRxed.end ())
                {
                  wbCqi = (*itWbCqi).second;
                }
              else
                {
                  wbCqi = 1; // lowest value fro trying a transmission
                }

              uint8_t cqi1 = sbCqi.at (0);
              uint8_t cqi2 = 1;
              if (sbCqi.size () > 1)
                {
                  cqi2 = sbCqi.at (1);
                }
              if ((cqi1 > 0)||(cqi2 > 0)) // CQI == 0 means "out of range" (see table 7.2.3-1 of 36.213)
                {
                  if (LcActivePerFlow ((*it)) > 0)
                    {
                      // this UE has data to transmit
                      double achievableSbRate = 0.0;
                      double achievableWbRate = 0.0;
                      uint8_t sbMcs = 0;
                      uint8_t wbMcs = 0; 
                      for (uint8_t k = 0; k < nLayer; k++)
                        {
                          if (sbCqi.size () > k)
                            {
                              sbMcs = m_amc->GetMcsFromCqi (sbCqi.at (k));
                            }
                          else
                            {
                              // no info on this subband -> worst MCS
                              sbMcs = 0;
                            }
                          achievableSbRate += ((m_amc->GetTbSizeFromMcs (sbMcs, rbgSize) / 8) / 0.001);   // = TB size / TTI
                          wbMcs = m_amc->GetMcsFromCqi (wbCqi);
                          achievableWbRate += ((m_amc->GetTbSizeFromMcs (wbMcs, rbgSize) / 8) / 0.001);   // = TB size / TTI
                        }

                      double metric = achievableSbRate / achievableWbRate;

                      if (metric > rcqiMax)
                        {
                          rcqiMax = metric;
                          itMax = it;
                        }
                    }
                }   // end if cqi
              
            } // end for m_rlcBufferReq

          if (itMax == m_flowStatsDl.end ())
            {
              // no UE available for this RB
              NS_LOG_INFO (this << " any UE found");
            }
          else
            {
              rbgMap.at (i) = true;
              std::map <uint16_t, std::vector <uint16_t> >::iterator itMap;
              itMap = allocationMap.find ((*itMax));
              if (itMap == allocationMap.end ())
                {
                  // insert new element
                  std::vector <uint16_t> tempMap;
                  tempMap.push_back (i);
                  allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax), tempMap));
                }
              else
                {
                  (*itMap).second.push_back (i);
                }
              NS_LOG_INFO (this << " UE assigned " << (*itMax));
            }
        } // end for RBG free
    } // end for RBGs

  // generate the transmission opportunities by grouping the RBGs of the same RNTI and
  // creating the correspondent DCIs
  std::map <uint16_t, std::vector <uint16_t> >::iterator itMap = allocationMap.begin ();
  while (itMap != allocationMap.end ())
    {
      // create new BuildDataListElement_s for this LC
      BuildDataListElement_s newEl;
      newEl.m_rnti = (*itMap).first;
      // create the DlDciListElement_s
      DlDciListElement_s newDci;
      newDci.m_rnti = (*itMap).first;
      newDci.m_harqProcess = UpdateHarqProcessId ((*itMap).first);

      uint16_t lcActives = LcActivePerFlow ((*itMap).first);
      NS_LOG_INFO (this << "Allocate user " << newEl.m_rnti << " rbg " << lcActives);
      if (lcActives == 0)
        {
          // Set to max value, to avoid divide by 0 below
          lcActives = (uint16_t)65535; // UINT16_MAX;
        }
      uint16_t RgbPerRnti = (*itMap).second.size ();
      std::map <uint16_t,SbMeasResult_s>::iterator itCqi;
      itCqi = m_a30CqiRxed.find ((*itMap).first);
      std::map <uint16_t,uint8_t>::iterator itTxMode;
      itTxMode = m_uesTxMode.find ((*itMap).first);
      if (itTxMode == m_uesTxMode.end ())
        {
          NS_FATAL_ERROR ("No Transmission Mode info on user " << (*itMap).first);
        }
      int nLayer = TransmissionModesLayers::TxMode2LayerNum ((*itTxMode).second);
      std::vector <uint8_t> worstCqi (2, 15);
      if (itCqi != m_a30CqiRxed.end ())
        {
          for (uint16_t k = 0; k < (*itMap).second.size (); k++)
            {
              if ((*itCqi).second.m_higherLayerSelected.size () > (*itMap).second.at (k))
                {
                  NS_LOG_INFO (this << " RBG " << (*itMap).second.at (k) << " CQI " << (uint16_t)((*itCqi).second.m_higherLayerSelected.at ((*itMap).second.at (k)).m_sbCqi.at (0)) );
                  for (uint8_t j = 0; j < nLayer; j++)
                    {
                      if ((*itCqi).second.m_higherLayerSelected.at ((*itMap).second.at (k)).m_sbCqi.size () > j)
                        {
                          if (((*itCqi).second.m_higherLayerSelected.at ((*itMap).second.at (k)).m_sbCqi.at (j)) < worstCqi.at (j))
                            {
                              worstCqi.at (j) = ((*itCqi).second.m_higherLayerSelected.at ((*itMap).second.at (k)).m_sbCqi.at (j));
                            }
                        }
                      else
                        {
                          // no CQI for this layer of this suband -> worst one
                          worstCqi.at (j) = 1;
                        }
                    }
                }
              else
                {
                  for (uint8_t j = 0; j < nLayer; j++)
                    {
                      worstCqi.at (j) = 1; // try with lowest MCS in RBG with no info on channel
                    }
                }
            }
        }
      else
        {
          for (uint8_t j = 0; j < nLayer; j++)
            {
              worstCqi.at (j) = 1; // try with lowest MCS in RBG with no info on channel
            }
        }
      for (uint8_t j = 0; j < nLayer; j++)
        {
          NS_LOG_INFO (this << " Layer " << (uint16_t)j << " CQI selected " << (uint16_t)worstCqi.at (j));
        }
      uint32_t bytesTxed = 0;
      for (uint8_t j = 0; j < nLayer; j++)
        {
          newDci.m_mcs.push_back (m_amc->GetMcsFromCqi (worstCqi.at (j)));
          int tbSize = (m_amc->GetTbSizeFromMcs (newDci.m_mcs.at (j), RgbPerRnti * rbgSize) / 8); // (size of TB in bytes according to table 7.1.7.2.1-1 of 36.213)
          newDci.m_tbsSize.push_back (tbSize);
          NS_LOG_INFO (this << " Layer " << (uint16_t)j << " MCS selected" << m_amc->GetMcsFromCqi (worstCqi.at (j)));

          bytesTxed += tbSize;
        }

      newDci.m_resAlloc = 0;  // only allocation type 0 at this stage
      newDci.m_rbBitmap = 0; // TBD (32 bit bitmap see 7.1.6 of 36.213)
      uint32_t rbgMask = 0;
      for (uint16_t k = 0; k < (*itMap).second.size (); k++)
        {
          rbgMask = rbgMask + (0x1 << (*itMap).second.at (k));
          NS_LOG_INFO (this << " Allocated RBG " << (*itMap).second.at (k));
        }
      newDci.m_rbBitmap = rbgMask; // (32 bit bitmap see 7.1.6 of 36.213)

      // create the rlc PDUs -> equally divide resources among actives LCs
      std::map <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator itBufReq;
      for (itBufReq = m_rlcBufferReq.begin (); itBufReq != m_rlcBufferReq.end (); itBufReq++)
        {
          if (((*itBufReq).first.m_rnti == (*itMap).first)
              && (((*itBufReq).second.m_rlcTransmissionQueueSize > 0)
                  || ((*itBufReq).second.m_rlcRetransmissionQueueSize > 0)
                  || ((*itBufReq).second.m_rlcStatusPduSize > 0) ))
            {
              std::vector <struct RlcPduListElement_s> newRlcPduLe;
              for (uint8_t j = 0; j < nLayer; j++)
                {
                  RlcPduListElement_s newRlcEl;
                  newRlcEl.m_logicalChannelIdentity = (*itBufReq).first.m_lcId;
                  newRlcEl.m_size = newDci.m_tbsSize.at (j) / lcActives;
                  NS_LOG_INFO (this << " LCID " << (uint32_t) newRlcEl.m_logicalChannelIdentity << " size " << newRlcEl.m_size << " layer " << (uint16_t)j);
                  newRlcPduLe.push_back (newRlcEl);
                  UpdateDlRlcBufferInfo (newDci.m_rnti, newRlcEl.m_logicalChannelIdentity, newRlcEl.m_size);
                  if (m_harqOn == true)
                    {
                      // store RLC PDU list for HARQ
                      std::map <uint16_t, DlHarqRlcPduListBuffer_t>::iterator itRlcPdu =  m_dlHarqProcessesRlcPduListBuffer.find ((*itMap).first);
                      if (itRlcPdu == m_dlHarqProcessesRlcPduListBuffer.end ())
                        {
                          NS_FATAL_ERROR ("Unable to find RlcPdcList in HARQ buffer for RNTI " << (*itMap).first);
                        }
                      (*itRlcPdu).second.at (j).at (newDci.m_harqProcess).push_back (newRlcEl);
                    }
                }
              newEl.m_rlcPduList.push_back (newRlcPduLe);
            }
          if ((*itBufReq).first.m_rnti > (*itMap).first)
            {
              break;
            }
        }
      for (uint8_t j = 0; j < nLayer; j++)
        {
          newDci.m_ndi.push_back (1);
          newDci.m_rv.push_back (0);
        }

      newEl.m_dci = newDci;

      if (m_harqOn == true)
        {
          // store DCI for HARQ
          std::map <uint16_t, DlHarqProcessesDciBuffer_t>::iterator itDci = m_dlHarqProcessesDciBuffer.find (newEl.m_rnti);
          if (itDci == m_dlHarqProcessesDciBuffer.end ())
            {
              NS_FATAL_ERROR ("Unable to find RNTI entry in DCI HARQ buffer for RNTI " << newEl.m_rnti);
            }
          (*itDci).second.at (newDci.m_harqProcess) = newDci;
          // refresh timer
          std::map <uint16_t, DlHarqProcessesTimer_t>::iterator itHarqTimer =  m_dlHarqProcessesTimer.find (newEl.m_rnti);
          if (itHarqTimer== m_dlHarqProcessesTimer.end ())
            {
              NS_FATAL_ERROR ("Unable to find HARQ timer for RNTI " << (uint16_t)newEl.m_rnti);
            }
          (*itHarqTimer).second.at (newDci.m_harqProcess) = 0;
        }

      // ...more parameters -> ingored in this version

      ret.m_buildDataList.push_back (newEl);

      itMap++;
    } // end while allocation
  ret.m_nrOfPdcchOfdmSymbols = 1;   

  m_schedSapUser->SchedDlConfigInd (ret);


  return;
}

void
TtaFfMacScheduler::DoSchedDlRachInfoReq (const struct FfMacSchedSapProvider::SchedDlRachInfoReqParameters& params)
{
  NS_LOG_FUNCTION (this);

  m_rachList = params.m_rachList;
  
  return;
}

void
TtaFfMacScheduler::DoSchedDlCqiInfoReq (const struct FfMacSchedSapProvider::SchedDlCqiInfoReqParameters& params)
{
  NS_LOG_FUNCTION (this);

  for (unsigned int i = 0; i < params.m_cqiList.size (); i++)
    {
      if ( params.m_cqiList.at (i).m_cqiType == CqiListElement_s::P10 )
        {
          // wideband CQI reporting
          std::map <uint16_t,uint8_t>::iterator it;
          uint16_t rnti = params.m_cqiList.at (i).m_rnti;
          it = m_p10CqiRxed.find (rnti);
          if (it == m_p10CqiRxed.end ())
            {
              // create the new entry
              m_p10CqiRxed.insert ( std::pair<uint16_t, uint8_t > (rnti, params.m_cqiList.at (i).m_wbCqi.at (0)) ); // only codeword 0 at this stage (SISO)
              // generate correspondent timer
              m_p10CqiTimers.insert ( std::pair<uint16_t, uint32_t > (rnti, m_cqiTimersThreshold));
            }
          else
            {
              // update the CQI value and refresh correspondent timer
              (*it).second = params.m_cqiList.at (i).m_wbCqi.at (0);
              // update correspondent timer
              std::map <uint16_t,uint32_t>::iterator itTimers;
              itTimers = m_p10CqiTimers.find (rnti);
              (*itTimers).second = m_cqiTimersThreshold;
            }
        }
      else if ( params.m_cqiList.at (i).m_cqiType == CqiListElement_s::A30 )
        {
          // subband CQI reporting high layer configured
          std::map <uint16_t,SbMeasResult_s>::iterator it;
          uint16_t rnti = params.m_cqiList.at (i).m_rnti;
          it = m_a30CqiRxed.find (rnti);
          if (it == m_a30CqiRxed.end ())
            {
              // create the new entry
              m_a30CqiRxed.insert ( std::pair<uint16_t, SbMeasResult_s > (rnti, params.m_cqiList.at (i).m_sbMeasResult) );
              m_a30CqiTimers.insert ( std::pair<uint16_t, uint32_t > (rnti, m_cqiTimersThreshold));
            }
          else
            {
              // update the CQI value and refresh correspondent timer
              (*it).second = params.m_cqiList.at (i).m_sbMeasResult;
              std::map <uint16_t,uint32_t>::iterator itTimers;
              itTimers = m_a30CqiTimers.find (rnti);
              (*itTimers).second = m_cqiTimersThreshold;
            }
        }
      else
        {
          NS_LOG_ERROR (this << " CQI type unknown");
        }
    }

  return;
}


double
TtaFfMacScheduler::EstimateUlSinr (uint16_t rnti, uint16_t rb)
{
  std::map <uint16_t, std::vector <double> >::iterator itCqi = m_ueCqi.find (rnti);
  if (itCqi == m_ueCqi.end ())
    {
      // no cqi info about this UE
      return (NO_SINR);

    }
  else
    {
      // take the average SINR value among the available
      double sinrSum = 0;
      int sinrNum = 0;
      for (uint32_t i = 0; i < m_cschedCellConfig.m_ulBandwidth; i++)
        {
          double sinr = (*itCqi).second.at (i);
          if (sinr != NO_SINR)
            {
              sinrSum += sinr;
              sinrNum++;
            }
        }
      double estimatedSinr = (sinrNum > 0) ? (sinrSum / sinrNum) : DBL_MAX;
      // store the value
      (*itCqi).second.at (rb) = estimatedSinr;
      return (estimatedSinr);
    }
}

void
TtaFfMacScheduler::DoSchedUlTriggerReq (const struct FfMacSchedSapProvider::SchedUlTriggerReqParameters& params)
{
  NS_LOG_FUNCTION (this << " UL - Frame no. " << (params.m_sfnSf >> 4) << " subframe no. " << (0xF & params.m_sfnSf) << " size " << params.m_ulInfoList.size ());

  RefreshUlCqiMaps ();

  // Generate RBs map
  FfMacSchedSapUser::SchedUlConfigIndParameters ret;
  std::vector <bool> rbMap;
  uint16_t rbAllocatedNum = 0;
  std::set <uint16_t> rntiAllocated;
  std::vector <uint16_t> rbgAllocationMap;
  // update with RACH allocation map
  rbgAllocationMap = m_rachAllocationMap;
  //rbgAllocationMap.resize (m_cschedCellConfig.m_ulBandwidth, 0);
  m_rachAllocationMap.clear ();
  m_rachAllocationMap.resize (m_cschedCellConfig.m_ulBandwidth, 0);

  rbMap.resize (m_cschedCellConfig.m_ulBandwidth, false);
  // remove RACH allocation
  for (uint16_t i = 0; i < m_cschedCellConfig.m_ulBandwidth; i++)
    {
      if (rbgAllocationMap.at (i) != 0)
        {
          rbMap.at (i) = true;
          NS_LOG_DEBUG (this << " Allocated for RACH " << i);
        }
    }


  if (m_harqOn == true)
    {
      //   Process UL HARQ feedback
      //   update UL HARQ proc id
      std::map <uint16_t, uint8_t>::iterator itProcId;
      for (itProcId = m_ulHarqCurrentProcessId.begin (); itProcId != m_ulHarqCurrentProcessId.end (); itProcId++)
        {
          (*itProcId).second = ((*itProcId).second + 1) % HARQ_PROC_NUM;
        }

      for (uint16_t i = 0; i < params.m_ulInfoList.size (); i++)
        {        
          if (params.m_ulInfoList.at (i).m_receptionStatus == UlInfoListElement_s::NotOk)
            {
              // retx correspondent block: retrieve the UL-DCI
              uint16_t rnti = params.m_ulInfoList.at (i).m_rnti;
              itProcId = m_ulHarqCurrentProcessId.find (rnti);
              if (itProcId == m_ulHarqCurrentProcessId.end ())
                {
                  NS_LOG_ERROR ("No info find in HARQ buffer for UE (might change eNB) " << rnti);
                }
              uint8_t harqId = (uint8_t)((*itProcId).second - HARQ_PERIOD) % HARQ_PROC_NUM;
              NS_LOG_INFO (this << " UL-HARQ retx RNTI " << rnti << " harqId " << (uint16_t)harqId << " i " << i << " size "  << params.m_ulInfoList.size ());
              std::map <uint16_t, UlHarqProcessesDciBuffer_t>::iterator itHarq = m_ulHarqProcessesDciBuffer.find (rnti);
              if (itHarq == m_ulHarqProcessesDciBuffer.end ())
                {
                  NS_LOG_ERROR ("No info find in HARQ buffer for UE (might change eNB) " << rnti);
                  continue;
                }
              UlDciListElement_s dci = (*itHarq).second.at (harqId);
              std::map <uint16_t, UlHarqProcessesStatus_t>::iterator itStat = m_ulHarqProcessesStatus.find (rnti);
              if (itStat == m_ulHarqProcessesStatus.end ())
                {
                  NS_LOG_ERROR ("No info find in HARQ buffer for UE (might change eNB) " << rnti);
                }
              if ((*itStat).second.at (harqId) >= 3)
                {
                  NS_LOG_INFO ("Max number of retransmissions reached (UL)-> drop process");
                  continue;
                }
              bool free = true;
              for (int j = dci.m_rbStart; j < dci.m_rbStart + dci.m_rbLen; j++)
                {
                  if (rbMap.at (j) == true)
                    {
                      free = false;
                      NS_LOG_INFO (this << " BUSY " << j);
                    }
                }
              if (free)
                {
                  // retx on the same RBs
                  for (int j = dci.m_rbStart; j < dci.m_rbStart + dci.m_rbLen; j++)
                    {
                      rbMap.at (j) = true;
                      rbgAllocationMap.at (j) = dci.m_rnti;
                      NS_LOG_INFO ("\tRB " << j);
                      rbAllocatedNum++;
                    }
                  NS_LOG_INFO (this << " Send retx in the same RBs " << (uint16_t)dci.m_rbStart << " to " << dci.m_rbStart + dci.m_rbLen << " RV " << (*itStat).second.at (harqId) + 1);
                }
              else
                {
                  NS_LOG_INFO ("Cannot allocate retx due to RACH allocations for UE " << rnti);
                  continue;
                }
              dci.m_ndi = 0;
              // Update HARQ buffers with new HarqId
              (*itStat).second.at ((*itProcId).second) = (*itStat).second.at (harqId) + 1;
              (*itStat).second.at (harqId) = 0;
              (*itHarq).second.at ((*itProcId).second) = dci;
              ret.m_dciList.push_back (dci);
              rntiAllocated.insert (dci.m_rnti);
            }
            else
            {
              NS_LOG_INFO (this << " HARQ-ACK feedback from RNTI " << params.m_ulInfoList.at (i).m_rnti);
            }
        }
    }

  std::map <uint16_t,uint32_t>::iterator it;
  int nflows = 0;

  for (it = m_ceBsrRxed.begin (); it != m_ceBsrRxed.end (); it++)
    {
      std::set <uint16_t>::iterator itRnti = rntiAllocated.find ((*it).first);
      // select UEs with queues not empty and not yet allocated for HARQ
      if (((*it).second > 0)&&(itRnti == rntiAllocated.end ()))
        {
          nflows++;
        }
    }

  if (nflows == 0)
    {
      if (ret.m_dciList.size () > 0)
        {
          m_schedSapUser->SchedUlConfigInd (ret);
        }
        
      return;  // no flows to be scheduled
    }


  // Divide the remaining resources equally among the active users starting from the subsequent one served last scheduling trigger
  uint16_t rbPerFlow = (m_cschedCellConfig.m_ulBandwidth) / (nflows + rntiAllocated.size ());
  if (rbPerFlow < 3)
    {
      rbPerFlow = 3;  // at least 3 rbg per flow (till available resource) to ensure TxOpportunity >= 7 bytes
    }
  int rbAllocated = 0;

  if (m_nextRntiUl != 0)
    {
      for (it = m_ceBsrRxed.begin (); it != m_ceBsrRxed.end (); it++)
        {
          if ((*it).first == m_nextRntiUl)
            {
              break;
            }
        }
      if (it == m_ceBsrRxed.end ())
        {
          NS_LOG_ERROR (this << " no user found");
        }
    }
  else
    {
      it = m_ceBsrRxed.begin ();
      m_nextRntiUl = (*it).first;
    }
  do
    {
      std::set <uint16_t>::iterator itRnti = rntiAllocated.find ((*it).first);
      if ((itRnti != rntiAllocated.end ())||((*it).second == 0))
        {
          // UE already allocated for UL-HARQ -> skip it
          NS_LOG_DEBUG (this << " UE already allocated in HARQ -> discared, RNTI " << (*it).first);
          it++;
          if (it == m_ceBsrRxed.end ())
            {
              // restart from the first
              it = m_ceBsrRxed.begin ();
            }
          continue;
        }
      if (rbAllocated + rbPerFlow - 1 > m_cschedCellConfig.m_ulBandwidth)
        {
          // limit to physical resources last resource assignment
          rbPerFlow = m_cschedCellConfig.m_ulBandwidth - rbAllocated;
          // at least 3 rbg per flow to ensure TxOpportunity >= 7 bytes
          if (rbPerFlow < 3)
            {
              // terminate allocation
              rbPerFlow = 0;      
            }
        }

      UlDciListElement_s uldci;
      uldci.m_rnti = (*it).first;
      uldci.m_rbLen = rbPerFlow;
      bool allocated = false;
      NS_LOG_INFO (this << " RB Allocated " << rbAllocated << " rbPerFlow " << rbPerFlow << " flows " << nflows);
      while ((!allocated)&&((rbAllocated + rbPerFlow - 1) < m_cschedCellConfig.m_ulBandwidth) && (rbPerFlow != 0))
        {
          // check availability
          bool free = true;
          for (uint16_t j = rbAllocated; j < rbAllocated + rbPerFlow; j++)
            {
              if (rbMap.at (j) == true)
                {
                  free = false;
                  break;
                }
            }
          if (free)
            {
              uldci.m_rbStart = rbAllocated;

              for (uint16_t j = rbAllocated; j < rbAllocated + rbPerFlow; j++)
                {
                  rbMap.at (j) = true;
                  // store info on allocation for managing ul-cqi interpretation
                  rbgAllocationMap.at (j) = (*it).first;
                }
              rbAllocated += rbPerFlow;
              allocated = true;
              break;
            }
          rbAllocated++;
          if (rbAllocated + rbPerFlow - 1 > m_cschedCellConfig.m_ulBandwidth)
            {
              // limit to physical resources last resource assignment
              rbPerFlow = m_cschedCellConfig.m_ulBandwidth - rbAllocated;
              // at least 3 rbg per flow to ensure TxOpportunity >= 7 bytes
              if (rbPerFlow < 3)
                {
                  // terminate allocation
                  rbPerFlow = 0;                 
                }
            }
        }
      if (!allocated)
        {
          // unable to allocate new resource: finish scheduling
          m_nextRntiUl = (*it).first;
          if (ret.m_dciList.size () > 0)
            {
              m_schedSapUser->SchedUlConfigInd (ret);
            }
          m_allocationMaps.insert (std::pair <uint16_t, std::vector <uint16_t> > (params.m_sfnSf, rbgAllocationMap));
          return;
        }



      std::map <uint16_t, std::vector <double> >::iterator itCqi = m_ueCqi.find ((*it).first);
      int cqi = 0;
      if (itCqi == m_ueCqi.end ())
        {
          // no cqi info about this UE
          uldci.m_mcs = 0; // MCS 0 -> UL-AMC TBD
        }
      else
        {
          // take the lowest CQI value (worst RB)
          double minSinr = (*itCqi).second.at (uldci.m_rbStart);
          if (minSinr == NO_SINR)
            {
              minSinr = EstimateUlSinr ((*it).first, uldci.m_rbStart);
            }
          for (uint16_t i = uldci.m_rbStart; i < uldci.m_rbStart + uldci.m_rbLen; i++)
            {
              double sinr = (*itCqi).second.at (i);
              if (sinr == NO_SINR)
                {
                  sinr = EstimateUlSinr ((*it).first, i);
                }
              if ((*itCqi).second.at (i) < minSinr)
                {
                  minSinr = (*itCqi).second.at (i);
                }
            }

          // translate SINR -> cqi: WILD ACK: same as DL
          double s = log2 ( 1 + (
                                 std::pow (10, minSinr / 10 )  /
                                 ( (-std::log (5.0 * 0.00005 )) / 1.5) ));
          cqi = m_amc->GetCqiFromSpectralEfficiency (s);
          if (cqi == 0)
            {
              it++;
              if (it == m_ceBsrRxed.end ())
                {
                  // restart from the first
                  it = m_ceBsrRxed.begin ();
                }
              NS_LOG_DEBUG (this << " UE discared for CQI=0, RNTI " << uldci.m_rnti);
              // remove UE from allocation map
              for (uint16_t i = uldci.m_rbStart; i < uldci.m_rbStart + uldci.m_rbLen; i++)
                {
                  rbgAllocationMap.at (i) = 0;
                }
              continue; // CQI == 0 means "out of range" (see table 7.2.3-1 of 36.213)
            }
          uldci.m_mcs = m_amc->GetMcsFromCqi (cqi);
        }

      uldci.m_tbSize = (m_amc->GetTbSizeFromMcs (uldci.m_mcs, rbPerFlow) / 8);
      UpdateUlRlcBufferInfo (uldci.m_rnti, uldci.m_tbSize);
      uldci.m_ndi = 1;
      uldci.m_cceIndex = 0;
      uldci.m_aggrLevel = 1;
      uldci.m_ueTxAntennaSelection = 3; // antenna selection OFF
      uldci.m_hopping = false;
      uldci.m_n2Dmrs = 0;
      uldci.m_tpc = 0; // no power control
      uldci.m_cqiRequest = false; // only period CQI at this stage
      uldci.m_ulIndex = 0; // TDD parameter
      uldci.m_dai = 1; // TDD parameter
      uldci.m_freqHopping = 0;
      uldci.m_pdcchPowerOffset = 0; // not used
      ret.m_dciList.push_back (uldci);
      // store DCI for HARQ_PERIOD
      uint8_t harqId = 0;
      if (m_harqOn == true)
        {
          std::map <uint16_t, uint8_t>::iterator itProcId;
          itProcId = m_ulHarqCurrentProcessId.find (uldci.m_rnti);
          if (itProcId == m_ulHarqCurrentProcessId.end ())
            {
              NS_FATAL_ERROR ("No info find in HARQ buffer for UE " << uldci.m_rnti);
            }
          harqId = (*itProcId).second;
          std::map <uint16_t, UlHarqProcessesDciBuffer_t>::iterator itDci = m_ulHarqProcessesDciBuffer.find (uldci.m_rnti);
          if (itDci == m_ulHarqProcessesDciBuffer.end ())
            {
              NS_FATAL_ERROR ("Unable to find RNTI entry in UL DCI HARQ buffer for RNTI " << uldci.m_rnti);
            }
          (*itDci).second.at (harqId) = uldci;
        }

      NS_LOG_INFO (this << " UE Allocation RNTI " << (*it).first << " startPRB " << (uint32_t)uldci.m_rbStart << " nPRB " << (uint32_t)uldci.m_rbLen << " CQI " << cqi << " MCS " << (uint32_t)uldci.m_mcs << " TBsize " << uldci.m_tbSize << " RbAlloc " << rbAllocated << " harqId " << (uint16_t)harqId);


      it++;
      if (it == m_ceBsrRxed.end ())
        {
          // restart from the first
          it = m_ceBsrRxed.begin ();
        }
      if ((rbAllocated == m_cschedCellConfig.m_ulBandwidth) || (rbPerFlow == 0))
        {
          // Stop allocation: no more PRBs
          m_nextRntiUl = (*it).first;
          break;
        }
    }
  while (((*it).first != m_nextRntiUl)&&(rbPerFlow!=0));


  m_allocationMaps.insert (std::pair <uint16_t, std::vector <uint16_t> > (params.m_sfnSf, rbgAllocationMap));
  m_schedSapUser->SchedUlConfigInd (ret);

  return;
}

void
TtaFfMacScheduler::DoSchedUlNoiseInterferenceReq (const struct FfMacSchedSapProvider::SchedUlNoiseInterferenceReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  return;
}

void
TtaFfMacScheduler::DoSchedUlSrInfoReq (const struct FfMacSchedSapProvider::SchedUlSrInfoReqParameters& params)
{
  NS_LOG_FUNCTION (this);
  return;
}

void
TtaFfMacScheduler::DoSchedUlMacCtrlInfoReq (const struct FfMacSchedSapProvider::SchedUlMacCtrlInfoReqParameters& params)
{
  NS_LOG_FUNCTION (this);

  std::map <uint16_t,uint32_t>::iterator it;

  for (unsigned int i = 0; i < params.m_macCeList.size (); i++)
    {
      if ( params.m_macCeList.at (i).m_macCeType == MacCeListElement_s::BSR )
        {
          // buffer status report
          // note that this scheduler does not differentiate the
          // allocation according to which LCGs have more/less bytes
          // to send.
          // Hence the BSR of different LCGs are just summed up to get
          // a total queue size that is used for allocation purposes.

          uint32_t buffer = 0;
          for (uint8_t lcg = 0; lcg < 4; ++lcg)
            {
              uint8_t bsrId = params.m_macCeList.at (i).m_macCeValue.m_bufferStatus.at (lcg);
              buffer += BufferSizeLevelBsr::BsrId2BufferSize (bsrId);
            }
          
          uint16_t rnti = params.m_macCeList.at (i).m_rnti;
          NS_LOG_LOGIC (this << "RNTI=" << rnti << " buffer=" << buffer);
          it = m_ceBsrRxed.find (rnti);
          if (it == m_ceBsrRxed.end ())
            {
              // create the new entry
              m_ceBsrRxed.insert ( std::pair<uint16_t, uint32_t > (rnti, buffer));
            }
          else
            {
              // update the buffer size value
              (*it).second = buffer;
            }
        }
    }

  return;
}

void
TtaFfMacScheduler::DoSchedUlCqiInfoReq (const struct FfMacSchedSapProvider::SchedUlCqiInfoReqParameters& params)
{
  NS_LOG_FUNCTION (this);
// retrieve the allocation for this subframe
  switch (m_ulCqiFilter)
    {
    case FfMacScheduler::SRS_UL_CQI:
      {
        // filter all the CQIs that are not SRS based
        if (params.m_ulCqi.m_type != UlCqi_s::SRS)
          {
            return;
          }
      }
      break;
    case FfMacScheduler::PUSCH_UL_CQI:
      {
        // filter all the CQIs that are not SRS based
        if (params.m_ulCqi.m_type != UlCqi_s::PUSCH)
          {
            return;
          }
      }
    case FfMacScheduler::ALL_UL_CQI:
      break;

    default:
      NS_FATAL_ERROR ("Unknown UL CQI type");
    }

  switch (params.m_ulCqi.m_type)
    {
    case UlCqi_s::PUSCH:
      {
        std::map <uint16_t, std::vector <uint16_t> >::iterator itMap;
        std::map <uint16_t, std::vector <double> >::iterator itCqi;
        NS_LOG_DEBUG (this << " Collect PUSCH CQIs of Frame no. " << (params.m_sfnSf >> 4) << " subframe no. " << (0xF & params.m_sfnSf));
        itMap = m_allocationMaps.find (params.m_sfnSf);
        if (itMap == m_allocationMaps.end ())
          {
            return;
          }
        for (uint32_t i = 0; i < (*itMap).second.size (); i++)
          {
            // convert from fixed point notation Sxxxxxxxxxxx.xxx to double
            double sinr = LteFfConverter::fpS11dot3toDouble (params.m_ulCqi.m_sinr.at (i));
            itCqi = m_ueCqi.find ((*itMap).second.at (i));
            if (itCqi == m_ueCqi.end ())
              {
                // create a new entry
                std::vector <double> newCqi;
                for (uint32_t j = 0; j < m_cschedCellConfig.m_ulBandwidth; j++)
                  {
                    if (i == j)
                      {
                        newCqi.push_back (sinr);
                      }
                    else
                      {
                        // initialize with NO_SINR value.
                        newCqi.push_back (NO_SINR);
                      }

                  }
                m_ueCqi.insert (std::pair <uint16_t, std::vector <double> > ((*itMap).second.at (i), newCqi));
                // generate correspondent timer
                m_ueCqiTimers.insert (std::pair <uint16_t, uint32_t > ((*itMap).second.at (i), m_cqiTimersThreshold));
              }
            else
              {
                // update the value
                (*itCqi).second.at (i) = sinr;
                //NS_LOG_DEBUG (this << " RNTI " << (*itMap).second.at (i) << " RB " << i << " SINR " << sinr);
                // update correspondent timer
                std::map <uint16_t, uint32_t>::iterator itTimers;
                itTimers = m_ueCqiTimers.find ((*itMap).second.at (i));
                (*itTimers).second = m_cqiTimersThreshold;

              }

          }
        // remove obsolete info on allocation
        m_allocationMaps.erase (itMap);
      }
      break;
    case UlCqi_s::SRS:
      {
        // get the RNTI from vendor specific parameters
        uint16_t rnti = 0;
        NS_ASSERT (params.m_vendorSpecificList.size () > 0);
        for (uint16_t i = 0; i < params.m_vendorSpecificList.size (); i++)
          {
            if (params.m_vendorSpecificList.at (i).m_type == SRS_CQI_RNTI_VSP)
              {
                Ptr<SrsCqiRntiVsp> vsp = DynamicCast<SrsCqiRntiVsp> (params.m_vendorSpecificList.at (i).m_value);
                rnti = vsp->GetRnti ();
              }
          }
        std::map <uint16_t, std::vector <double> >::iterator itCqi;
        itCqi = m_ueCqi.find (rnti);
        if (itCqi == m_ueCqi.end ())
          {
            // create a new entry
            std::vector <double> newCqi;
            for (uint32_t j = 0; j < m_cschedCellConfig.m_ulBandwidth; j++)
              {
                double sinr = LteFfConverter::fpS11dot3toDouble (params.m_ulCqi.m_sinr.at (j));
                newCqi.push_back (sinr);
                NS_LOG_INFO (this << " RNTI " << rnti << " new SRS-CQI for RB  " << j << " value " << sinr);

              }
            m_ueCqi.insert (std::pair <uint16_t, std::vector <double> > (rnti, newCqi));
            // generate correspondent timer
            m_ueCqiTimers.insert (std::pair <uint16_t, uint32_t > (rnti, m_cqiTimersThreshold));
          }
        else
          {
            // update the values
            for (uint32_t j = 0; j < m_cschedCellConfig.m_ulBandwidth; j++)
              {
                double sinr = LteFfConverter::fpS11dot3toDouble (params.m_ulCqi.m_sinr.at (j));
                (*itCqi).second.at (j) = sinr;
                NS_LOG_INFO (this << " RNTI " << rnti << " update SRS-CQI for RB  " << j << " value " << sinr);
              }
            // update correspondent timer
            std::map <uint16_t, uint32_t>::iterator itTimers;
            itTimers = m_ueCqiTimers.find (rnti);
            (*itTimers).second = m_cqiTimersThreshold;

          }


      }
      break;
    case UlCqi_s::PUCCH_1:
    case UlCqi_s::PUCCH_2:
    case UlCqi_s::PRACH:
      {
        NS_FATAL_ERROR ("TtaFfMacScheduler supports only PUSCH and SRS UL-CQIs");
      }
      break;
    default:
      NS_FATAL_ERROR ("Unknown type of UL-CQI");
    }
  return;
}

void
TtaFfMacScheduler::RefreshDlCqiMaps (void)
{
  // refresh DL CQI P01 Map
  std::map <uint16_t,uint32_t>::iterator itP10 = m_p10CqiTimers.begin ();
  while (itP10 != m_p10CqiTimers.end ())
    {
      NS_LOG_INFO (this << " P10-CQI for user " << (*itP10).first << " is " << (uint32_t)(*itP10).second << " thr " << (uint32_t)m_cqiTimersThreshold);
      if ((*itP10).second == 0)
        {
          // delete correspondent entries
          std::map <uint16_t,uint8_t>::iterator itMap = m_p10CqiRxed.find ((*itP10).first);
          NS_ASSERT_MSG (itMap != m_p10CqiRxed.end (), " Does not find CQI report for user " << (*itP10).first);
          NS_LOG_INFO (this << " P10-CQI expired for user " << (*itP10).first);
          m_p10CqiRxed.erase (itMap);
          std::map <uint16_t,uint32_t>::iterator temp = itP10;
          itP10++;
          m_p10CqiTimers.erase (temp);
        }
      else
        {
          (*itP10).second--;
          itP10++;
        }
    }

  // refresh DL CQI A30 Map
  std::map <uint16_t,uint32_t>::iterator itA30 = m_a30CqiTimers.begin ();
  while (itA30 != m_a30CqiTimers.end ())
    {
      NS_LOG_INFO (this << " A30-CQI for user " << (*itA30).first << " is " << (uint32_t)(*itA30).second << " thr " << (uint32_t)m_cqiTimersThreshold);
      if ((*itA30).second == 0)
        {
          // delete correspondent entries
          std::map <uint16_t,SbMeasResult_s>::iterator itMap = m_a30CqiRxed.find ((*itA30).first);
          NS_ASSERT_MSG (itMap != m_a30CqiRxed.end (), " Does not find CQI report for user " << (*itA30).first);
          NS_LOG_INFO (this << " A30-CQI expired for user " << (*itA30).first);
          m_a30CqiRxed.erase (itMap);
          std::map <uint16_t,uint32_t>::iterator temp = itA30;
          itA30++;
          m_a30CqiTimers.erase (temp);
        }
      else
        {
          (*itA30).second--;
          itA30++;
        }
    }

  return;
}


void
TtaFfMacScheduler::RefreshUlCqiMaps (void)
{
  // refresh UL CQI  Map
  std::map <uint16_t,uint32_t>::iterator itUl = m_ueCqiTimers.begin ();
  while (itUl != m_ueCqiTimers.end ())
    {
      NS_LOG_INFO (this << " UL-CQI for user " << (*itUl).first << " is " << (uint32_t)(*itUl).second << " thr " << (uint32_t)m_cqiTimersThreshold);
      if ((*itUl).second == 0)
        {
          // delete correspondent entries
          std::map <uint16_t, std::vector <double> >::iterator itMap = m_ueCqi.find ((*itUl).first);
          NS_ASSERT_MSG (itMap != m_ueCqi.end (), " Does not find CQI report for user " << (*itUl).first);
          NS_LOG_INFO (this << " UL-CQI exired for user " << (*itUl).first);
          (*itMap).second.clear ();
          m_ueCqi.erase (itMap);
          std::map <uint16_t,uint32_t>::iterator temp = itUl;
          itUl++;
          m_ueCqiTimers.erase (temp);
        }
      else
        {
          (*itUl).second--;
          itUl++;
        }
    }

  return;
}

void
TtaFfMacScheduler::UpdateDlRlcBufferInfo (uint16_t rnti, uint8_t lcid, uint16_t size)
{
  std::map<LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;
  LteFlowId_t flow (rnti, lcid);
  it = m_rlcBufferReq.find (flow);
  if (it != m_rlcBufferReq.end ())
    {
      NS_LOG_INFO (this << " UE " << rnti << " LC " << (uint16_t)lcid << " txqueue " << (*it).second.m_rlcTransmissionQueueSize << " retxqueue " << (*it).second.m_rlcRetransmissionQueueSize << " status " << (*it).second.m_rlcStatusPduSize << " decrease " << size);
      // Update queues: RLC tx order Status, ReTx, Tx
      // Update status queue
      if (((*it).second.m_rlcStatusPduSize > 0) && (size >= (*it).second.m_rlcStatusPduSize))
        {
           (*it).second.m_rlcStatusPduSize = 0;
        }
      else if (((*it).second.m_rlcRetransmissionQueueSize > 0) && (size >= (*it).second.m_rlcRetransmissionQueueSize))
        {
          (*it).second.m_rlcRetransmissionQueueSize = 0;
        }
      else if ((*it).second.m_rlcTransmissionQueueSize > 0)
        {
          uint32_t rlcOverhead;
          if (lcid == 1)
            {
              // for SRB1 (using RLC AM) it's better to
              // overestimate RLC overhead rather than
              // underestimate it and risk unneeded
              // segmentation which increases delay 
              rlcOverhead = 4;                                  
            }
          else
            {
              // minimum RLC overhead due to header
              rlcOverhead = 2;
            }
          // update transmission queue
          if ((*it).second.m_rlcTransmissionQueueSize <= size - rlcOverhead)
            {
              (*it).second.m_rlcTransmissionQueueSize = 0;
            }
          else
            {                    
              (*it).second.m_rlcTransmissionQueueSize -= size - rlcOverhead;
            }
        }
    }
  else
    {
      NS_LOG_ERROR (this << " Does not find DL RLC Buffer Report of UE " << rnti);
    }
}

void
TtaFfMacScheduler::UpdateUlRlcBufferInfo (uint16_t rnti, uint16_t size)
{

  size = size - 2; // remove the minimum RLC overhead
  std::map <uint16_t,uint32_t>::iterator it = m_ceBsrRxed.find (rnti);
  if (it != m_ceBsrRxed.end ())
    {
      NS_LOG_INFO (this << " UE " << rnti << " size " << size << " BSR " << (*it).second);
      if ((*it).second >= size)
        {
          (*it).second -= size;
        }
      else
        {
          (*it).second = 0;
        }
    }
  else
    {
      NS_LOG_ERROR (this << " Does not find BSR report info of UE " << rnti);
    }

}

void
TtaFfMacScheduler::TransmissionModeConfigurationUpdate (uint16_t rnti, uint8_t txMode)
{
  NS_LOG_FUNCTION (this << " RNTI " << rnti << " txMode " << (uint16_t)txMode);
  FfMacCschedSapUser::CschedUeConfigUpdateIndParameters params;
  params.m_rnti = rnti;
  params.m_transmissionMode = txMode;
  m_cschedSapUser->CschedUeConfigUpdateInd (params);
}


}