/*
 * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The OpenAirInterface Software Alliance licenses this file to You under
 * the OAI Public License, Version 1.1  (the "License"); you may not use this file
 * except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.openairinterface.org/?page_id=698
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *-------------------------------------------------------------------------------
 * For more information about the OpenAirInterface (OAI) Software Alliance:
 *      contact@openairinterface.org
 */

/*! \file pre_processor.c
 * \brief eNB scheduler preprocessing fuction prior to scheduling
 * \author Navid Nikaein and Ankit Bhamri
 * \date 2013 - 2014
 * \email navid.nikaein@eurecom.fr
 * \version 1.0
 * @ingroup _mac

 */

#define _GNU_SOURCE
#include <stdlib.h>

#include "assertions.h"
#include "LAYER2/MAC/mac.h"
#include "LAYER2/MAC/mac_proto.h"
#include "LAYER2/MAC/mac_extern.h"
#include "UTIL/LOG/log.h"
#include "UTIL/LOG/vcd_signal_dumper.h"
#include "UTIL/OPT/opt.h"
#include "OCG.h"
#include "OCG_extern.h"
#include "RRC/LTE/rrc_extern.h"
#include "RRC/L2_INTERFACE/openair_rrc_L2_interface.h"
#include "rlc.h"
#include "PHY/LTE_TRANSPORT/transport_common_proto.h"

#include "common/ran_context.h"

extern RAN_CONTEXT_t RC;

#define DEBUG_eNB_SCHEDULER 1
#define DEBUG_HEADER_PARSING 1
//#define DEBUG_PACKET_TRACE 1

extern float slice_percentage[MAX_NUM_SLICES];
extern float slice_percentage_uplink[MAX_NUM_SLICES];
extern uint32_t sorting_policy[MAX_NUM_SLICES];

extern int slice_maxmcs[MAX_NUM_SLICES];
extern int slice_maxmcs_uplink[MAX_NUM_SLICES];


//#define ICIC 0

/* this function checks that get_eNB_UE_stats returns
 * a non-NULL pointer for all the active CCs of an UE
 */
/*
int phy_stats_exist(module_id_t Mod_id, int rnti)
{
  int CC_id;
  int i;
  int UE_id          = find_UE_id(Mod_id, rnti);
  UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
  if (UE_id == -1) {
    LOG_W(MAC, "[eNB %d] UE %x not found, should be there (in phy_stats_exist)\n",
	  Mod_id, rnti);
    return 0;
  }
  if (UE_list->numactiveCCs[UE_id] == 0) {
    LOG_W(MAC, "[eNB %d] UE %x has no active CC (in phy_stats_exist)\n",
	  Mod_id, rnti);
    return 0;
  }
  for (i = 0; i < UE_list->numactiveCCs[UE_id]; i++) {
    CC_id = UE_list->ordered_CCids[i][UE_id];
    if (mac_xface->get_eNB_UE_stats(Mod_id, CC_id, rnti) == NULL)
      return 0;
  }
  return 1;
}
*/

// This function stores the downlink buffer for all the logical channels
void
store_dlsch_buffer(module_id_t Mod_id, slice_id_t slice_id, frame_t frameP,
		   sub_frame_t subframeP)
{

    int UE_id, i;
    rnti_t rnti;
    mac_rlc_status_resp_t rlc_status;
    UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
    UE_TEMPLATE *UE_template;

    for (UE_id = 0; UE_id < MAX_MOBILES_PER_ENB; UE_id++) {
	if (UE_list->active[UE_id] != TRUE)
	    continue;

	if (!ue_slice_membership(UE_id, slice_id))
	    continue;

	UE_template =
	    &UE_list->UE_template[UE_PCCID(Mod_id, UE_id)][UE_id];

	// clear logical channel interface variables
	UE_template->dl_buffer_total = 0;
	UE_template->dl_pdus_total = 0;

	for (i = 0; i < MAX_NUM_LCID; i++) {
	    UE_template->dl_buffer_info[i] = 0;
	    UE_template->dl_pdus_in_buffer[i] = 0;
	    UE_template->dl_buffer_head_sdu_creation_time[i] = 0;
	    UE_template->dl_buffer_head_sdu_remaining_size_to_send[i] = 0;
	}


	rnti = UE_RNTI(Mod_id, UE_id);

        for (i = 0; i < MAX_NUM_LCID; i++) {    // loop over all the logical channels

	    rlc_status =
		mac_rlc_status_ind(Mod_id, rnti, Mod_id, frameP, subframeP,
				   ENB_FLAG_YES, MBMS_FLAG_NO, i, 0
#if (RRC_VERSION >= MAKE_VERSION(14, 0, 0))
                   ,0, 0
#endif
                   );

	    UE_template->dl_buffer_info[i] = rlc_status.bytes_in_buffer;	//storing the dlsch buffer for each logical channel
	    UE_template->dl_pdus_in_buffer[i] = rlc_status.pdus_in_buffer;
	    UE_template->dl_buffer_head_sdu_creation_time[i] =
		rlc_status.head_sdu_creation_time;
	    UE_template->dl_buffer_head_sdu_creation_time_max =
		cmax(UE_template->dl_buffer_head_sdu_creation_time_max,
		     rlc_status.head_sdu_creation_time);
	    UE_template->dl_buffer_head_sdu_remaining_size_to_send[i] =
		rlc_status.head_sdu_remaining_size_to_send;
	    UE_template->dl_buffer_head_sdu_is_segmented[i] =
		rlc_status.head_sdu_is_segmented;
	    UE_template->dl_buffer_total += UE_template->dl_buffer_info[i];	//storing the total dlsch buffer
	    UE_template->dl_pdus_total +=
		UE_template->dl_pdus_in_buffer[i];

#ifdef DEBUG_eNB_SCHEDULER

	    /* note for dl_buffer_head_sdu_remaining_size_to_send[i] :
	     * 0 if head SDU has not been segmented (yet), else remaining size not already segmented and sent
	     */
	    if (UE_template->dl_buffer_info[i] > 0)
		LOG_D(MAC,
		      "[eNB %d][SLICE %d] Frame %d Subframe %d : RLC status for UE %d in LCID%d: total of %d pdus and size %d, head sdu queuing time %d, remaining size %d, is segmeneted %d \n",
		      Mod_id, slice_id, frameP, subframeP, UE_id,
		      i, UE_template->dl_pdus_in_buffer[i],
		      UE_template->dl_buffer_info[i],
		      UE_template->dl_buffer_head_sdu_creation_time[i],
		      UE_template->
		      dl_buffer_head_sdu_remaining_size_to_send[i],
		      UE_template->dl_buffer_head_sdu_is_segmented[i]);

#endif

	}

	//#ifdef DEBUG_eNB_SCHEDULER
	if (UE_template->dl_buffer_total > 0)
	    LOG_D(MAC,
		  "[eNB %d] Frame %d Subframe %d : RLC status for UE %d : total DL buffer size %d and total number of pdu %d \n",
		  Mod_id, frameP, subframeP, UE_id,
		  UE_template->dl_buffer_total,
		  UE_template->dl_pdus_total);

	//#endif
    }
}


// This function returns the estimated number of RBs required by each UE for downlink scheduling
void
assign_rbs_required(module_id_t Mod_id,
			slice_id_t slice_id,
		    frame_t frameP,
		    sub_frame_t subframe,
		    uint16_t
		    nb_rbs_required[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB],
		    int min_rb_unit[NFAPI_CC_MAX])
{

    uint16_t TBS = 0;

    int UE_id, n, i, j, CC_id, pCCid, tmp;
    UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
    eNB_UE_STATS *eNB_UE_stats, *eNB_UE_stats_i, *eNB_UE_stats_j;
    int N_RB_DL;

    // clear rb allocations across all CC_id
    for (UE_id = 0; UE_id < MAX_MOBILES_PER_ENB; UE_id++) {
	if (UE_list->active[UE_id] != TRUE)
	    continue;
	if (!ue_slice_membership(UE_id, slice_id))
	    continue;
	pCCid = UE_PCCID(Mod_id, UE_id);

	//update CQI information across component carriers
	for (n = 0; n < UE_list->numactiveCCs[UE_id]; n++) {
	    CC_id = UE_list->ordered_CCids[n][UE_id];
	    eNB_UE_stats = &UE_list->eNB_UE_stats[CC_id][UE_id];

	    eNB_UE_stats->dlsch_mcs1 =cmin(cqi_to_mcs[UE_list->UE_sched_ctrl[UE_id].dl_cqi[CC_id]],
									   slice_maxmcs[slice_id]);

	}

	// provide the list of CCs sorted according to MCS
	for (i = 0; i < UE_list->numactiveCCs[UE_id]; i++) {
	    eNB_UE_stats_i =
		&UE_list->eNB_UE_stats[UE_list->
				       ordered_CCids[i][UE_id]][UE_id];
	    for (j = i + 1; j < UE_list->numactiveCCs[UE_id]; j++) {
		DevAssert(j < NFAPI_CC_MAX);
		eNB_UE_stats_j =
		    &UE_list->
		    eNB_UE_stats[UE_list->ordered_CCids[j][UE_id]][UE_id];
		if (eNB_UE_stats_j->dlsch_mcs1 >
		    eNB_UE_stats_i->dlsch_mcs1) {
		    tmp = UE_list->ordered_CCids[i][UE_id];
		    UE_list->ordered_CCids[i][UE_id] =
			UE_list->ordered_CCids[j][UE_id];
		    UE_list->ordered_CCids[j][UE_id] = tmp;
		}
	    }
	}

	if (UE_list->UE_template[pCCid][UE_id].dl_buffer_total > 0) {
	    LOG_D(MAC, "[preprocessor] assign RB for UE %d\n", UE_id);

	    for (i = 0; i < UE_list->numactiveCCs[UE_id]; i++) {
		CC_id = UE_list->ordered_CCids[i][UE_id];
		eNB_UE_stats = &UE_list->eNB_UE_stats[CC_id][UE_id];

		if (eNB_UE_stats->dlsch_mcs1 == 0) {
		    nb_rbs_required[CC_id][UE_id] = 4;	// don't let the TBS get too small
		} else {
		    nb_rbs_required[CC_id][UE_id] = min_rb_unit[CC_id];
		}

		TBS =
		    get_TBS_DL(eNB_UE_stats->dlsch_mcs1,
			       nb_rbs_required[CC_id][UE_id]);

		LOG_D(MAC,
		      "[preprocessor] start RB assignement for UE %d CC_id %d dl buffer %d (RB unit %d, MCS %d, TBS %d) \n",
		      UE_id, CC_id,
		      UE_list->UE_template[pCCid][UE_id].dl_buffer_total,
		      nb_rbs_required[CC_id][UE_id],
		      eNB_UE_stats->dlsch_mcs1, TBS);

		N_RB_DL =
		    to_prb(RC.mac[Mod_id]->common_channels[CC_id].
			   mib->message.dl_Bandwidth);

		UE_list->UE_sched_ctrl[UE_id].max_rbs_allowed_slice[CC_id][slice_id]= flexran_nb_rbs_allowed_slice(slice_percentage[slice_id],N_RB_DL);

		/* calculating required number of RBs for each UE */
		while (TBS <
		       UE_list->UE_template[pCCid][UE_id].
		       dl_buffer_total) {
		    nb_rbs_required[CC_id][UE_id] += min_rb_unit[CC_id];

		    if (nb_rbs_required[CC_id][UE_id] > UE_list->UE_sched_ctrl[UE_id].max_rbs_allowed_slice[CC_id][slice_id]) {
			TBS = get_TBS_DL(eNB_UE_stats->dlsch_mcs1, UE_list->UE_sched_ctrl[UE_id].max_rbs_allowed_slice[CC_id][slice_id]);
			nb_rbs_required[CC_id][UE_id] = UE_list->UE_sched_ctrl[UE_id].max_rbs_allowed_slice[CC_id][slice_id];
			break;
		    }

		    TBS =
			get_TBS_DL(eNB_UE_stats->dlsch_mcs1,
				   nb_rbs_required[CC_id][UE_id]);
		}		// end of while

		LOG_D(MAC,
		      "[eNB %d] Frame %d: UE %d on CC %d: RB unit %d,  nb_required RB %d (TBS %d, mcs %d)\n",
		      Mod_id, frameP, UE_id, CC_id, min_rb_unit[CC_id],
		      nb_rbs_required[CC_id][UE_id], TBS,
		      eNB_UE_stats->dlsch_mcs1);
	    }
	}
    }
}


// This function scans all CC_ids for a particular UE to find the maximum round index of its HARQ processes

int
maxround(module_id_t Mod_id, uint16_t rnti, int frame,
	 sub_frame_t subframe, uint8_t ul_flag)
{

    uint8_t round, round_max = 0, UE_id;
    int CC_id, harq_pid;
    UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
    COMMON_channels_t *cc;

    for (CC_id = 0; CC_id < RC.nb_mac_CC[Mod_id]; CC_id++) {

	cc = &RC.mac[Mod_id]->common_channels[CC_id];

	UE_id = find_UE_id(Mod_id, rnti);

	harq_pid = frame_subframe2_dl_harq_pid(cc->tdd_Config,frame ,subframe);

	round = UE_list->UE_sched_ctrl[UE_id].round[CC_id][harq_pid];
	if (round > round_max) {
	    round_max = round;
	}
    }

    return round_max;
}

// This function scans all CC_ids for a particular UE to find the maximum DL CQI
// it returns -1 if the UE is not found in PHY layer (get_eNB_UE_stats gives NULL)
int maxcqi(module_id_t Mod_id, int32_t UE_id)
{
    UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
    int CC_id, n;
    int CQI = 0;

    for (n = 0; n < UE_list->numactiveCCs[UE_id]; n++) {
	CC_id = UE_list->ordered_CCids[n][UE_id];

	if (UE_list->UE_sched_ctrl[UE_id].dl_cqi[CC_id] > CQI) {
	    CQI = UE_list->UE_sched_ctrl[UE_id].dl_cqi[CC_id];
	}
    }

    return CQI;
}

struct sort_ue_dl_params {
    int Mod_idP;
    int frameP;
    int subframeP;
    int slice_id;
};

static int ue_dl_compare(const void *_a, const void *_b, void *_params)
{
    struct sort_ue_dl_params *params = _params;
    UE_list_t *UE_list = &RC.mac[params->Mod_idP]->UE_list;

	int i;
	int slice_id = params->slice_id;
    int UE_id1 = *(const int *) _a;
    int UE_id2 = *(const int *) _b;

    int rnti1 = UE_RNTI(params->Mod_idP, UE_id1);
    int pCC_id1 = UE_PCCID(params->Mod_idP, UE_id1);
    int round1 = maxround(params->Mod_idP, rnti1, params->frameP, params->subframeP, 1);

    int rnti2 = UE_RNTI(params->Mod_idP, UE_id2);
    int pCC_id2 = UE_PCCID(params->Mod_idP, UE_id2);
    int round2 = maxround(params->Mod_idP, rnti2, params->frameP, params->subframeP, 1);

    int cqi1 = maxcqi(params->Mod_idP, UE_id1);
    int cqi2 = maxcqi(params->Mod_idP, UE_id2);

  for (i = 0; i < CR_NUM; ++i) {
    switch (UE_list->sorting_criteria[slice_id][i]) {

      case CR_ROUND :
        if (round1 > round2)
          return -1;
        if (round1 < round2)
          return 1;
        break;

      case CR_SRB12 :
        if (UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_info[1] +
            UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_info[2] >
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_info[1] +
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_info[2])
          return -1;
        if (UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_info[1] +
            UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_info[2] <
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_info[1] +
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_info[2])
          return 1;
        break;

      case CR_HOL :
        if (UE_list-> UE_template[pCC_id1][UE_id1].dl_buffer_head_sdu_creation_time_max >
            UE_list-> UE_template[pCC_id2][UE_id2].dl_buffer_head_sdu_creation_time_max)
          return -1;
        if (UE_list-> UE_template[pCC_id1][UE_id1].dl_buffer_head_sdu_creation_time_max <
            UE_list-> UE_template[pCC_id2][UE_id2].dl_buffer_head_sdu_creation_time_max)
          return 1;
        break;

      case CR_LC :
        if (UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_total >
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_total)
          return -1;
        if (UE_list->UE_template[pCC_id1][UE_id1].dl_buffer_total <
            UE_list->UE_template[pCC_id2][UE_id2].dl_buffer_total)
          return 1;
        break;

      case CR_CQI :
        if (cqi1 > cqi2)
          return -1;
        if (cqi1 < cqi2)
          return 1;

      default :
        break;
    }
  }

    return 0;
}

void decode_sorting_policy(module_id_t Mod_idP, slice_id_t slice_id) {
	int i;

	UE_list_t *UE_list = &RC.mac[Mod_idP]->UE_list;
	uint32_t policy = sorting_policy[slice_id];
	uint32_t mask = 0x0000000F;
    uint16_t criterion;

	for(i = 0; i < CR_NUM; ++i) {
		criterion = (uint16_t)(policy >> 4*(CR_NUM - 1 - i) & mask);
        if (criterion >= CR_NUM) {
          LOG_W(MAC, "Invalid criterion in slice %d policy, revert to default policy \n", slice_id);
          sorting_policy[slice_id] = 0x1234;
          break;
        }
      UE_list->sorting_criteria[slice_id][i] = criterion;
	}
}


// This fuction sorts the UE in order their dlsch buffer and CQI
void sort_UEs(module_id_t Mod_idP, slice_id_t slice_id, int frameP, sub_frame_t subframeP)
{
    int i;
    int list[MAX_MOBILES_PER_ENB];
    int list_size = 0;
    int rnti;
    struct sort_ue_dl_params params = { Mod_idP, frameP, subframeP, slice_id };

    UE_list_t *UE_list = &RC.mac[Mod_idP]->UE_list;

	for (i = 0; i < MAX_MOBILES_PER_ENB; i++) {

		if (UE_list->active[i] == FALSE)
			continue;
		if ((rnti = UE_RNTI(Mod_idP, i)) == NOT_A_RNTI)
			continue;
		if (!ue_slice_membership(i, slice_id))
			continue;

		list[list_size] = i;
		list_size++;
	}

	decode_sorting_policy(Mod_idP, slice_id);

	qsort_r(list, list_size, sizeof(int), ue_dl_compare, &params);

	if (list_size) {
		for (i = 0; i < list_size - 1; i++)
			UE_list->next[list[i]] = list[i + 1];
		UE_list->next[list[list_size - 1]] = -1;
		UE_list->head = list[0];
	} else {
		UE_list->head = -1;
	}
}

void dlsch_scheduler_pre_processor_accounting(module_id_t Mod_id,
                                              slice_id_t slice_id,
                                              frame_t frameP,
                                              sub_frame_t subframeP,
                                              int N_RBG[NFAPI_CC_MAX],
                                              int min_rb_unit[NFAPI_CC_MAX],
                                              uint8_t rballoc_sub[NFAPI_CC_MAX][N_RBG_MAX],
                                              uint8_t MIMO_mode_indicator[NFAPI_CC_MAX][N_RBG_MAX],
                                              uint16_t nb_rbs_required[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB]) {


  int UE_id, CC_id;
  int ii, r1;

  rnti_t rnti;
  uint8_t harq_pid, round, transmission_mode;
  uint8_t total_rbs_used[NFAPI_CC_MAX];
  uint8_t total_ue_count[NFAPI_CC_MAX];
  uint16_t average_rbs_per_user[NFAPI_CC_MAX];
  uint16_t nb_rbs_required_remaining[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB];
  uint16_t nb_rbs_required_remaining_1[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB];

  int N_RB_DL;
  UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
  UE_sched_ctrl *ue_sched_ctl;
  COMMON_channels_t *cc;

  for (CC_id = 0; CC_id < RC.nb_mac_CC[Mod_id]; CC_id++) {
    total_ue_count[CC_id] = 0;
    total_rbs_used[CC_id] = 0;
    average_rbs_per_user[CC_id] = 0;
    for (UE_id = 0; UE_id < MAX_MOBILES_PER_ENB; ++UE_id) {
      nb_rbs_required_remaining[CC_id][UE_id] = 0;
    }
  }

  // loop over all active UEs
  for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {
    rnti = UE_RNTI(Mod_id, UE_id);

    if (rnti == NOT_A_RNTI)
      continue;
    if (!ue_slice_membership(UE_id, slice_id))
      continue;

    for (ii = 0; ii < UE_num_active_CC(UE_list, UE_id); ii++) {
      CC_id = UE_list->ordered_CCids[ii][UE_id];
      ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
      cc = &RC.mac[Mod_id]->common_channels[CC_id];
      // TODO Can we use subframe2harqpid() here?
      if (cc->tdd_Config)
        harq_pid = ((frameP * 10) + subframeP) % 10;
      else
        harq_pid = ((frameP * 10) + subframeP) & 7;
      round = ue_sched_ctl->round[CC_id][harq_pid];

      average_rbs_per_user[CC_id] = 0;

      if (round != 8) {
        nb_rbs_required[CC_id][UE_id] = UE_list->UE_template[CC_id][UE_id].nb_rb[harq_pid];
        total_rbs_used[CC_id] += nb_rbs_required[CC_id][UE_id];
      }

      //nb_rbs_required_remaining[UE_id] = nb_rbs_required[UE_id];
      if (nb_rbs_required[CC_id][UE_id] > 0) {
        total_ue_count[CC_id] = total_ue_count[CC_id] + 1;
      }
    }
  }

  // loop over all active UEs and calculate avg rb per user based on total active UEs
  for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {
    rnti = UE_RNTI(Mod_id, UE_id);

    if (rnti == NOT_A_RNTI)
      continue;
    if (UE_list->UE_sched_ctrl[UE_id].ul_out_of_sync == 1)
      continue;
    if (!ue_slice_membership(UE_id, slice_id))
      continue;

    for (ii = 0; ii < UE_num_active_CC(UE_list, UE_id); ii++) {
      CC_id = UE_list->ordered_CCids[ii][UE_id];

      // hypothetical assignment
      /*
       * If schedule is enabled and if the priority of the UEs is modified
       * The average rbs per logical channel per user will depend on the level of
       * priority. Concerning the hypothetical assignement, we should assign more
       * rbs to prioritized users. Maybe, we can do a mapping between the
       * average rbs per user and the level of priority or multiply the average rbs
       * per user by a coefficient which represents the degree of priority.
       */

      N_RB_DL = to_prb(RC.mac[Mod_id]->common_channels[CC_id].mib->message.dl_Bandwidth) - total_rbs_used[CC_id];

      // recalculate based on the what is left after retransmission
      ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
      ue_sched_ctl->max_rbs_allowed_slice[CC_id][slice_id] =
              flexran_nb_rbs_allowed_slice(slice_percentage[slice_id], N_RB_DL);

      if (total_ue_count[CC_id] == 0) {
        average_rbs_per_user[CC_id] = 0;
      } else if ((min_rb_unit[CC_id] * total_ue_count[CC_id]) <=
                 (ue_sched_ctl->max_rbs_allowed_slice[CC_id][slice_id])) {
        average_rbs_per_user[CC_id] =
                (uint16_t) floor(ue_sched_ctl->max_rbs_allowed_slice[CC_id][slice_id] / total_ue_count[CC_id]);
      } else {
        // consider the total number of use that can be scheduled UE
        average_rbs_per_user[CC_id] = min_rb_unit[CC_id];
      }
    }
  }

  // note: nb_rbs_required is assigned according to total_buffer_dl
  // extend nb_rbs_required to capture per LCID RB required
  for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {
    rnti = UE_RNTI(Mod_id, UE_id);

    if (rnti == NOT_A_RNTI)
      continue;
    if (!ue_slice_membership(UE_id, slice_id))
      continue;

    for (ii = 0; ii < UE_num_active_CC(UE_list, UE_id); ii++) {
      CC_id = UE_list->ordered_CCids[ii][UE_id];
      ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
      cc = &RC.mac[Mod_id]->common_channels[CC_id];
      harq_pid = frame_subframe2_dl_harq_pid(cc->tdd_Config,frameP ,subframeP);
      round = ue_sched_ctl->round[CC_id][harq_pid];

      // control channel or retransmission
      /* TODO: do we have to check for retransmission? */
      if (mac_eNB_get_rrc_status(Mod_id, rnti) < RRC_RECONFIGURED || round != 8) {
        nb_rbs_required_remaining_1[CC_id][UE_id] =
                nb_rbs_required[CC_id][UE_id];
      } else {
        nb_rbs_required_remaining_1[CC_id][UE_id] =
                cmin(average_rbs_per_user[CC_id], nb_rbs_required[CC_id][UE_id]);
      }
    }
  }

  //Allocation to UEs is done in 2 rounds,
  // 1st stage: average number of RBs allocated to each UE
  // 2nd stage: remaining RBs are allocated to high priority UEs
  for (r1 = 0; r1 < 2; r1++) {

    for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {
      for (ii = 0; ii < UE_num_active_CC(UE_list, UE_id); ii++) {
        CC_id = UE_list->ordered_CCids[ii][UE_id];

        if (r1 == 0) {
          nb_rbs_required_remaining[CC_id][UE_id] =
                  nb_rbs_required_remaining_1[CC_id][UE_id];
        } else {    // rb required based only on the buffer - rb allocated in the 1st round + extra reaming rb form the 1st round
          nb_rbs_required_remaining[CC_id][UE_id] =
                  nb_rbs_required[CC_id][UE_id] -
                  nb_rbs_required_remaining_1[CC_id][UE_id] +
                  nb_rbs_required_remaining[CC_id][UE_id];
          if (nb_rbs_required_remaining[CC_id][UE_id] < 0)
            abort();
        }

        if (nb_rbs_required[CC_id][UE_id] > 0)
          LOG_D(MAC,
                "round %d : nb_rbs_required_remaining[%d][%d]= %d (remaining_1 %d, required %d,  pre_nb_available_rbs %d, N_RBG %d, rb_unit %d)\n",
                r1, CC_id, UE_id,
                nb_rbs_required_remaining[CC_id][UE_id],
                nb_rbs_required_remaining_1[CC_id][UE_id],
                nb_rbs_required[CC_id][UE_id],
                UE_list->UE_sched_ctrl[UE_id].pre_nb_available_rbs[CC_id],
                N_RBG[CC_id],
                min_rb_unit[CC_id]);

      }
    }

    for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {

      for (ii = 0; ii < UE_num_active_CC(UE_list, UE_id); ii++) {

        CC_id = UE_list->ordered_CCids[ii][UE_id];
        // if there are UEs with traffic
        if (total_ue_count[CC_id] > 0) {
          // ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
          // round = ue_sched_ctl->round[CC_id][harq_pid];

          rnti = UE_RNTI(Mod_id, UE_id);

          // LOG_D(MAC,"UE %d rnti 0x\n", UE_id, rnti );
          if (rnti == NOT_A_RNTI)
            continue;
          if (!ue_slice_membership(UE_id, slice_id))
            continue;

          transmission_mode = get_tmode(Mod_id, CC_id, UE_id);
          // mac_xface->get_ue_active_harq_pid(Mod_id,CC_id,rnti,frameP,subframeP,&harq_pid,&round,0);
          // rrc_status = mac_eNB_get_rrc_status(Mod_id,rnti);
          /* 1st allocate for the retx */

          // retransmission in data channels
          // control channel in the 1st transmission
          // data channel for all TM
          LOG_T(MAC,
                "calling dlsch_scheduler_pre_processor_allocate .. \n ");
          dlsch_scheduler_pre_processor_allocate(Mod_id, UE_id,
                                                 CC_id,
                                                 N_RBG[CC_id],
                                                 transmission_mode,
                                                 min_rb_unit
                                                 [CC_id],
                                                 to_prb(RC.mac[Mod_id]->common_channels[CC_id].mib->message.dl_Bandwidth),
                                                 nb_rbs_required,
                                                 nb_rbs_required_remaining,
                                                 rballoc_sub,
                                                 MIMO_mode_indicator);

#ifdef TM5
          // data chanel TM5: to be revisited
          if ((round == 0) &&
          (transmission_mode == 5) &&
          (ue_sched_ctl->dl_pow_off[CC_id] != 1)) {

          for (j = 0; j < N_RBG[CC_id]; j += 2) {

              if ((((j == (N_RBG[CC_id] - 1))
                && (rballoc_sub[CC_id][j] == 0)
                && (ue_sched_ctl->
                    rballoc_sub_UE[CC_id][j] == 0))
               || ((j < (N_RBG[CC_id] - 1))
                   && (rballoc_sub[CC_id][j + 1] == 0)
                   &&
                   (ue_sched_ctl->rballoc_sub_UE
                    [CC_id][j + 1] == 0)))
              && (nb_rbs_required_remaining[CC_id][UE_id]
                  > 0)) {

              for (ii = UE_list->next[UE_id + 1]; ii >= 0;
                   ii = UE_list->next[ii]) {

                  UE_id2 = ii;
                  rnti2 = UE_RNTI(Mod_id, UE_id2);
                  ue_sched_ctl2 =
                  &UE_list->UE_sched_ctrl[UE_id2];
                  round2 = ue_sched_ctl2->round[CC_id];
                  if (rnti2 == NOT_A_RNTI)
                  continue;
                  if (UE_list->
                  UE_sched_ctrl
                  [UE_id2].ul_out_of_sync == 1)
                  continue;

                  eNB_UE_stats2 =
                  UE_list->
                  eNB_UE_stats[CC_id][UE_id2];
                  //mac_xface->get_ue_active_harq_pid(Mod_id,CC_id,rnti2,frameP,subframeP,&harq_pid2,&round2,0);

                  if ((mac_eNB_get_rrc_status
                   (Mod_id,
                    rnti2) >= RRC_RECONFIGURED)
                  && (round2 == 0)
                  &&
                  (get_tmode(Mod_id, CC_id, UE_id2)
                   == 5)
                  && (ue_sched_ctl->
                      dl_pow_off[CC_id] != 1)) {

                  if ((((j == (N_RBG[CC_id] - 1))
                        &&
                        (ue_sched_ctl->rballoc_sub_UE
                         [CC_id][j] == 0))
                       || ((j < (N_RBG[CC_id] - 1))
                       &&
                       (ue_sched_ctl->
                        rballoc_sub_UE[CC_id][j +
                                  1]
                        == 0)))
                      &&
                      (nb_rbs_required_remaining
                       [CC_id]
                       [UE_id2] > 0)) {

                      if ((((eNB_UE_stats2->
                         DL_pmi_single ^
                         eNB_UE_stats1->
                         DL_pmi_single)
                        << (14 - j)) & 0xc000) == 0x4000) {	//MU-MIMO only for 25 RBs configuration

                      rballoc_sub[CC_id][j] = 1;
                      ue_sched_ctl->
                          rballoc_sub_UE[CC_id]
                          [j] = 1;
                      ue_sched_ctl2->
                          rballoc_sub_UE[CC_id]
                          [j] = 1;
                      MIMO_mode_indicator[CC_id]
                          [j] = 0;

                      if (j < N_RBG[CC_id] - 1) {
                          rballoc_sub[CC_id][j +
                                     1] =
                          1;
                          ue_sched_ctl->
                          rballoc_sub_UE
                          [CC_id][j + 1] = 1;
                          ue_sched_ctl2->rballoc_sub_UE
                          [CC_id][j + 1] = 1;
                          MIMO_mode_indicator
                          [CC_id][j + 1]
                          = 0;
                      }

                      ue_sched_ctl->
                          dl_pow_off[CC_id]
                          = 0;
                      ue_sched_ctl2->
                          dl_pow_off[CC_id]
                          = 0;


                      if ((j == N_RBG[CC_id] - 1)
                          && ((N_RB_DL == 25)
                          || (N_RB_DL ==
                              50))) {

                          nb_rbs_required_remaining
                          [CC_id][UE_id] =
                          nb_rbs_required_remaining
                          [CC_id][UE_id] -
                          min_rb_unit[CC_id]
                          + 1;
                          ue_sched_ctl->pre_nb_available_rbs
                          [CC_id] =
                          ue_sched_ctl->pre_nb_available_rbs
                          [CC_id] +
                          min_rb_unit[CC_id]
                          - 1;
                          nb_rbs_required_remaining
                          [CC_id][UE_id2] =
                          nb_rbs_required_remaining
                          [CC_id][UE_id2] -
                          min_rb_unit[CC_id]
                          + 1;
                          ue_sched_ctl2->pre_nb_available_rbs
                          [CC_id] =
                          ue_sched_ctl2->pre_nb_available_rbs
                          [CC_id] +
                          min_rb_unit[CC_id]
                          - 1;
                      } else {

                          nb_rbs_required_remaining
                          [CC_id][UE_id] =
                          nb_rbs_required_remaining
                          [CC_id][UE_id] - 4;
                          ue_sched_ctl->pre_nb_available_rbs
                          [CC_id] =
                          ue_sched_ctl->pre_nb_available_rbs
                          [CC_id] + 4;
                          nb_rbs_required_remaining
                          [CC_id][UE_id2] =
                          nb_rbs_required_remaining
                          [CC_id][UE_id2] -
                          4;
                          ue_sched_ctl2->pre_nb_available_rbs
                          [CC_id] =
                          ue_sched_ctl2->pre_nb_available_rbs
                          [CC_id] + 4;
                      }

                      break;
                      }
                  }
                  }
              }
              }
          }
          }
#endif
        } // total_ue_count
      } // CC
    } // UE
  } // end of for for r1 and r2
}

// This function assigns pre-available RBS to each UE in specified sub-bands before scheduling is done
void
dlsch_scheduler_pre_processor(module_id_t Mod_id,
                              slice_id_t slice_id,
                              frame_t frameP,
                              sub_frame_t subframeP,
                              int N_RBG[NFAPI_CC_MAX],
                              int *mbsfn_flag) {

  int UE_id;
  uint8_t CC_id;
  uint16_t i, j;

  uint8_t rballoc_sub[NFAPI_CC_MAX][N_RBG_MAX];
  uint8_t MIMO_mode_indicator[NFAPI_CC_MAX][N_RBG_MAX]; // If TM5 is revisited, we can move this inside accounting

  int min_rb_unit[NFAPI_CC_MAX];
  uint16_t nb_rbs_required[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB];

  UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
  UE_sched_ctrl *ue_sched_ctl;
//  int rrc_status = RRC_IDLE;

#ifdef TM5
  int harq_pid1 = 0;
  int round1 = 0, round2 = 0;
  int UE_id2;
  uint16_t i1, i2, i3;
  rnti_t rnti1, rnti2;
  LTE_eNB_UE_stats *eNB_UE_stats1 = NULL;
  LTE_eNB_UE_stats *eNB_UE_stats2 = NULL;
  UE_sched_ctrl *ue_sched_ctl1, *ue_sched_ctl2;
#endif

  for (CC_id = 0; CC_id < RC.nb_mac_CC[Mod_id]; CC_id++) {

    if (mbsfn_flag[CC_id] > 0)    // If this CC is allocated for MBSFN skip it here
      continue;

    min_rb_unit[CC_id] = get_min_rb_unit(Mod_id, CC_id);

    for (UE_id = 0; UE_id < MAX_MOBILES_PER_ENB; ++UE_id) {
      if (UE_list->active[UE_id] != TRUE)
        continue;

      if (!ue_slice_membership(UE_id, slice_id))
        continue;

      // Initialize scheduling information for all active UEs
      dlsch_scheduler_pre_processor_reset(Mod_id,
                                          UE_id,
                                          CC_id,
                                          frameP,
                                          subframeP,
                                          N_RBG[CC_id],
                                          nb_rbs_required,
                                          rballoc_sub,
                                          MIMO_mode_indicator);

    }
  }

  // Store the DLSCH buffer for each logical channel
  store_dlsch_buffer(Mod_id, slice_id, frameP, subframeP);

  // Calculate the number of RBs required by each UE on the basis of logical channel's buffer
  assign_rbs_required(Mod_id, slice_id, frameP, subframeP, nb_rbs_required, min_rb_unit);

  // Sorts the user on the basis of dlsch logical channel buffer and CQI
  sort_UEs(Mod_id, slice_id, frameP, subframeP);

  // This function does the main allocation of the number of RBs
  dlsch_scheduler_pre_processor_accounting(Mod_id,
                                           slice_id,
                                           frameP,
                                           subframeP,
                                           N_RBG,
                                           min_rb_unit,
                                           rballoc_sub,
                                           MIMO_mode_indicator,
                                           nb_rbs_required);


#ifdef TM5
  // This has to be revisited!!!!
  for (CC_id = 0; CC_id < RC.nb_mac_CC[Mod_id]; CC_id++) {
  i1 = 0;
  i2 = 0;
  i3 = 0;

  for (j = 0; j < N_RBG[CC_id]; j++) {
      if (MIMO_mode_indicator[CC_id][j] == 2) {
      i1 = i1 + 1;
      } else if (MIMO_mode_indicator[CC_id][j] == 1) {
      i2 = i2 + 1;
      } else if (MIMO_mode_indicator[CC_id][j] == 0) {
      i3 = i3 + 1;
      }
  }

  if ((i1 < N_RBG[CC_id]) && (i2 > 0) && (i3 == 0)) {
      PHY_vars_eNB_g[Mod_id][CC_id]->check_for_SUMIMO_transmissions =
      PHY_vars_eNB_g[Mod_id][CC_id]->
      check_for_SUMIMO_transmissions + 1;
  }

  if (i3 == N_RBG[CC_id] && i1 == 0 && i2 == 0) {
      PHY_vars_eNB_g[Mod_id][CC_id]->FULL_MUMIMO_transmissions =
      PHY_vars_eNB_g[Mod_id][CC_id]->FULL_MUMIMO_transmissions +
      1;
  }

  if ((i1 < N_RBG[CC_id]) && (i3 > 0)) {
      PHY_vars_eNB_g[Mod_id][CC_id]->check_for_MUMIMO_transmissions =
      PHY_vars_eNB_g[Mod_id][CC_id]->
      check_for_MUMIMO_transmissions + 1;
  }

  PHY_vars_eNB_g[Mod_id][CC_id]->check_for_total_transmissions =
      PHY_vars_eNB_g[Mod_id][CC_id]->check_for_total_transmissions +
      1;

  }
#endif

  for (UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {

    ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
    for (i = 0; i < UE_num_active_CC(UE_list, UE_id); i++) {
      CC_id = UE_list->ordered_CCids[i][UE_id];
      //PHY_vars_eNB_g[Mod_id]->mu_mimo_mode[UE_id].dl_pow_off = dl_pow_off[UE_id];

      if (ue_sched_ctl->pre_nb_available_rbs[CC_id] > 0) {
        LOG_D(MAC, "******************DL Scheduling Information for UE%d ************************\n", UE_id);
        LOG_D(MAC, "dl power offset UE%d = %d \n", UE_id, ue_sched_ctl->dl_pow_off[CC_id]);
        LOG_D(MAC, "***********RB Alloc for every subband for UE%d ***********\n", UE_id);

        for (j = 0; j < N_RBG[CC_id]; j++) {
          //PHY_vars_eNB_g[Mod_id]->mu_mimo_mode[UE_id].rballoc_sub[UE_id] = rballoc_sub_UE[CC_id][UE_id][UE_id];
          LOG_D(MAC, "RB Alloc for UE%d and Subband%d = %d\n", UE_id, j, ue_sched_ctl->rballoc_sub_UE[CC_id][j]);
        }

        //PHY_vars_eNB_g[Mod_id]->mu_mimo_mode[UE_id].pre_nb_available_rbs = pre_nb_available_rbs[CC_id][UE_id];
        LOG_D(MAC, "[eNB %d][SLICE %d]Total RBs allocated for UE%d = %d\n",
              Mod_id, slice_id, UE_id, ue_sched_ctl->pre_nb_available_rbs[CC_id]);
      }
    }
  }
}

#define SF0_LIMIT 1

void
dlsch_scheduler_pre_processor_reset(int module_idP,
                                    int UE_id,
                                    uint8_t CC_id,
                                    int frameP,
                                    int subframeP,
                                    int N_RBG,
                                    uint16_t nb_rbs_required[NFAPI_CC_MAX]
                                    [MAX_MOBILES_PER_ENB],
                                    unsigned char
                                    rballoc_sub[NFAPI_CC_MAX]
                                    [N_RBG_MAX],
                                    unsigned char
                                    MIMO_mode_indicator[NFAPI_CC_MAX]
                                    [N_RBG_MAX])
{
  int i, j;
  UE_list_t *UE_list = &RC.mac[module_idP]->UE_list;
  UE_sched_ctrl *ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
  rnti_t rnti = UE_RNTI(module_idP, UE_id);

  uint8_t *vrb_map = RC.mac[module_idP]->common_channels[CC_id].vrb_map;
  int N_RB_DL =
          to_prb(RC.mac[module_idP]->common_channels[CC_id].mib->message.dl_Bandwidth);
  int RBGsize = N_RB_DL / N_RBG, RBGsize_last;
#ifdef SF0_LIMIT
  int sf0_upper = -1, sf0_lower = -1;
#endif


  LOG_D(MAC, "Running preprocessor for UE %d (%x)\n", UE_id, rnti);
  // initialize harq_pid and round

  if (ue_sched_ctl->ta_timer)
    ue_sched_ctl->ta_timer--;

    /*
       eNB_UE_stats *eNB_UE_stats;

       if (eNB_UE_stats == NULL)
       return;


       mac_xface->get_ue_active_harq_pid(module_idP,CC_id,rnti,
       frameP,subframeP,
       &ue_sched_ctl->harq_pid[CC_id],
       &ue_sched_ctl->round[CC_id],
       openair_harq_DL);

       if (ue_sched_ctl->ta_timer == 0) {

       // WE SHOULD PROTECT the eNB_UE_stats with a mutex here ...

       ue_sched_ctl->ta_timer = 20;  // wait 20 subframes before taking TA measurement from PHY
       switch (N_RB_DL) {
       case 6:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update;
       break;

       case 15:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update/2;
       break;

       case 25:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update/4;
       break;

       case 50:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update/8;
       break;

       case 75:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update/12;
       break;

       case 100:
       ue_sched_ctl->ta_update = eNB_UE_stats->timing_advance_update/16;
       break;
       }
       // clear the update in case PHY does not have a new measurement after timer expiry
       eNB_UE_stats->timing_advance_update =  0;
       }
       else {
       ue_sched_ctl->ta_timer--;
       ue_sched_ctl->ta_update =0; // don't trigger a timing advance command
       }


       if (UE_id==0) {
       VCD_SIGNAL_DUMPER_DUMP_VARIABLE_BY_NAME(VCD_SIGNAL_DUMPER_VARIABLES_UE0_TIMING_ADVANCE,ue_sched_ctl->ta_update);
       }
     */

  nb_rbs_required[CC_id][UE_id] = 0;
  ue_sched_ctl->pre_nb_available_rbs[CC_id] = 0;
  ue_sched_ctl->dl_pow_off[CC_id] = 2;

  switch (N_RB_DL) {
    case 6:
      RBGsize = 1;
      RBGsize_last = 1;
      break;
    case 15:
      RBGsize = 2;
      RBGsize_last = 1;
      break;
    case 25:
      RBGsize = 2;
      RBGsize_last = 1;
      break;
    case 50:
      RBGsize = 3;
      RBGsize_last = 2;
      break;
    case 75:
      RBGsize = 4;
      RBGsize_last = 3;
      break;
    case 100:
      RBGsize = 4;
      RBGsize_last = 4;
      break;
    default:
      AssertFatal(1 == 0, "unsupported RBs (%d)\n", N_RB_DL);
  }

#ifdef SF0_LIMIT
  switch (N_RBG) {
    case 6:
      sf0_lower = 0;
      sf0_upper = 5;
      break;
    case 8:
      sf0_lower = 2;
      sf0_upper = 5;
      break;
    case 13:
      sf0_lower = 4;
      sf0_upper = 7;
      break;
    case 17:
      sf0_lower = 7;
      sf0_upper = 9;
      break;
    case 25:
      sf0_lower = 11;
      sf0_upper = 13;
      break;
    default:
      AssertFatal(1 == 0, "unsupported RBs (%d)\n", N_RB_DL);
  }
#endif

  // Initialize Subbands according to VRB map
  for (i = 0; i < N_RBG; i++) {
    int rb_size = i == N_RBG - 1 ? RBGsize_last : RBGsize;

    ue_sched_ctl->rballoc_sub_UE[CC_id][i] = 0;
    rballoc_sub[CC_id][i] = 0;

#ifdef SF0_LIMIT
    // for avoiding 6+ PRBs around DC in subframe 0 (avoid excessive errors)
    /* TODO: make it proper - allocate those RBs, do not "protect" them, but
     * compute number of available REs and limit MCS according to the
     * TBS table 36.213 7.1.7.2.1-1 (can be done after pre-processor)
     */
    if (subframeP == 0 && i >= sf0_lower && i <= sf0_upper)
      rballoc_sub[CC_id][i] = 1;
#endif

    // for SI-RNTI,RA-RNTI and P-RNTI allocations
    for (j = 0; j < rb_size; j++) {
      if (vrb_map[j + (i * RBGsize)] != 0) {
        rballoc_sub[CC_id][i] = 1;
        LOG_D(MAC, "Frame %d, subframe %d : vrb %d allocated\n",
              frameP, subframeP, j + (i * RBGsize));
        break;
      }
    }
    LOG_D(MAC, "Frame %d Subframe %d CC_id %d RBG %i : rb_alloc %d\n",
          frameP, subframeP, CC_id, i, rballoc_sub[CC_id][i]);
    MIMO_mode_indicator[CC_id][i] = 2;
  }
}


void
dlsch_scheduler_pre_processor_allocate(module_id_t Mod_id,
				       int UE_id,
				       uint8_t CC_id,
				       int N_RBG,
				       int transmission_mode,
				       int min_rb_unit,
				       uint8_t N_RB_DL,
				       uint16_t nb_rbs_required[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB],
				       uint16_t nb_rbs_required_remaining[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB], 
				       unsigned char rballoc_sub[NFAPI_CC_MAX][N_RBG_MAX], 
				       unsigned char MIMO_mode_indicator[NFAPI_CC_MAX][N_RBG_MAX])
{

    int i;
    UE_list_t *UE_list = &RC.mac[Mod_id]->UE_list;
    UE_sched_ctrl *ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];

    for (i = 0; i < N_RBG; i++) {

	if ((rballoc_sub[CC_id][i] == 0) &&
	    (ue_sched_ctl->rballoc_sub_UE[CC_id][i] == 0) &&
	    (nb_rbs_required_remaining[CC_id][UE_id] > 0) &&
	    (ue_sched_ctl->pre_nb_available_rbs[CC_id] <
	     nb_rbs_required[CC_id][UE_id])) {

	    // if this UE is not scheduled for TM5
	    if (ue_sched_ctl->dl_pow_off[CC_id] != 0) {

		if ((i == N_RBG - 1)
		    && ((N_RB_DL == 25) || (N_RB_DL == 50))) {
		    if (nb_rbs_required_remaining[CC_id][UE_id] >=
			min_rb_unit - 1) {
			rballoc_sub[CC_id][i] = 1;
			ue_sched_ctl->rballoc_sub_UE[CC_id][i] = 1;
			MIMO_mode_indicator[CC_id][i] = 1;
			if (transmission_mode == 5) {
			    ue_sched_ctl->dl_pow_off[CC_id] = 1;
			}
			nb_rbs_required_remaining[CC_id][UE_id] =
			    nb_rbs_required_remaining[CC_id][UE_id] -
			    min_rb_unit + 1;
			ue_sched_ctl->pre_nb_available_rbs[CC_id] =
			    ue_sched_ctl->pre_nb_available_rbs[CC_id] +
			    min_rb_unit - 1;
		    }
		} else {
		    if (nb_rbs_required_remaining[CC_id][UE_id] >=
			min_rb_unit) {
			rballoc_sub[CC_id][i] = 1;
			ue_sched_ctl->rballoc_sub_UE[CC_id][i] = 1;
			MIMO_mode_indicator[CC_id][i] = 1;
			if (transmission_mode == 5) {
			    ue_sched_ctl->dl_pow_off[CC_id] = 1;
			}
			nb_rbs_required_remaining[CC_id][UE_id] =
			    nb_rbs_required_remaining[CC_id][UE_id] -
			    min_rb_unit;
			ue_sched_ctl->pre_nb_available_rbs[CC_id] =
			    ue_sched_ctl->pre_nb_available_rbs[CC_id] +
			    min_rb_unit;
		    }
		}
	    }			// dl_pow_off[CC_id][UE_id] ! = 0
	}
    }
}


/// ULSCH PRE_PROCESSOR

void ulsch_scheduler_pre_processor(module_id_t module_idP,
                                   slice_id_t slice_id,
                                   int frameP,
                                   sub_frame_t subframeP,
                                   unsigned char sched_subframeP,
                                   uint16_t *first_rb)
{

    int16_t i;
    uint16_t UE_id, n, r;
    uint8_t CC_id, harq_pid;
    uint16_t nb_allocated_rbs[NFAPI_CC_MAX][MAX_MOBILES_PER_ENB],
	total_allocated_rbs[NFAPI_CC_MAX],
	average_rbs_per_user[NFAPI_CC_MAX];
    int16_t total_remaining_rbs[NFAPI_CC_MAX];
    uint16_t total_ue_count[NFAPI_CC_MAX];
    rnti_t rnti = -1;
    UE_list_t *UE_list = &RC.mac[module_idP]->UE_list;
    UE_TEMPLATE *UE_template = 0;
    UE_sched_ctrl *ue_sched_ctl;
    int N_RB_UL = 0;

    LOG_D(MAC, "In ulsch_preprocessor: assign max mcs min rb\n");
    // maximize MCS and then allocate required RB according to the buffer occupancy with the limit of max available UL RB
    assign_max_mcs_min_rb(module_idP, slice_id, frameP, subframeP, first_rb);

    LOG_D(MAC, "In ulsch_preprocessor: sort ue \n");
    // sort ues
    sort_ue_ul(module_idP, frameP, subframeP);


    // we need to distribute RBs among UEs
    // step1:  reset the vars
    for (CC_id = 0; CC_id < RC.nb_mac_CC[module_idP]; CC_id++) {
      total_allocated_rbs[CC_id] = 0;
      total_remaining_rbs[CC_id] = 0;
      average_rbs_per_user[CC_id] = 0;
      total_ue_count[CC_id] = 0;
    }

    // Step 1.5: Calculate total_ue_count
    for (i = UE_list->head_ul; i >= 0; i = UE_list->next_ul[i]) {
      for (n = 0; n < UE_list->numactiveULCCs[i]; n++) {
        // This is the actual CC_id in the list
        CC_id = UE_list->ordered_ULCCids[n][i];
        UE_template = &UE_list->UE_template[CC_id][i];
        if (!ue_slice_membership(i, slice_id))
          continue;
        if (UE_template->pre_allocated_nb_rb_ul[slice_id] > 0) {
          total_ue_count[CC_id] += 1;
        }
      }
    }

    LOG_D(MAC, "In ulsch_preprocessor: step2 \n");
    // step 2: calculate the average rb per UE
    for (i = UE_list->head_ul; i >= 0; i = UE_list->next_ul[i]) {

      rnti = UE_RNTI(module_idP, i);
      UE_id = i;

      if (rnti == NOT_A_RNTI)
        continue;

      if (UE_list->UE_sched_ctrl[i].ul_out_of_sync == 1)
        continue;

      if (!ue_slice_membership(UE_id, slice_id))
          continue;

      LOG_D(MAC, "In ulsch_preprocessor: handling UE %d/%x\n", UE_id,
            rnti);
      for (n = 0; n < UE_list->numactiveULCCs[UE_id]; n++) {
        // This is the actual CC_id in the list
        CC_id = UE_list->ordered_ULCCids[n][UE_id];
        LOG_D(MAC,
              "In ulsch_preprocessor: handling UE %d/%x CCid %d\n",
              UE_id, rnti, CC_id);

        average_rbs_per_user[CC_id] = 0;

        /*
           if((mac_xface->get_nCCE_max(module_idP,CC_id,3,subframeP) - nCCE_to_be_used[CC_id])  > (1<<aggregation)) {
           nCCE_to_be_used[CC_id] = nCCE_to_be_used[CC_id] + (1<<aggregation);
           max_num_ue_to_be_scheduled+=1;
           } */



        N_RB_UL = to_prb(RC.mac[module_idP]->common_channels[CC_id].ul_Bandwidth);
        ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
        ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] = flexran_nb_rbs_allowed_slice(slice_percentage_uplink[slice_id],N_RB_UL);

        if (total_ue_count[CC_id] == 0) {
          average_rbs_per_user[CC_id] = 0;
        } else if (total_ue_count[CC_id] == 1) {    // increase the available RBs, special case,
          average_rbs_per_user[CC_id] = ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id] + 1;
        } else if (total_ue_count[CC_id] <= (ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id])) {
          average_rbs_per_user[CC_id] = (uint16_t) floor((ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id]) / total_ue_count[CC_id]);
        } else {
          average_rbs_per_user[CC_id] = 1;
          LOG_W(MAC,
                "[eNB %d] frame %d subframe %d: UE %d CC %d: can't get average rb per user (should not be here)\n",
                module_idP, frameP, subframeP, UE_id, CC_id);
        }
        if (total_ue_count[CC_id] > 0)
          LOG_D(MAC, "[eNB %d] Frame %d subframe %d: total ue to be scheduled %d\n",
                module_idP, frameP, subframeP, total_ue_count[CC_id]);
      }
    }

    // step 3: assigne RBS
    for (i = UE_list->head_ul; i >= 0; i = UE_list->next_ul[i]) {
      rnti = UE_RNTI(module_idP, i);

      if (rnti == NOT_A_RNTI)
        continue;
      if (UE_list->UE_sched_ctrl[i].ul_out_of_sync == 1)
        continue;
      if (!ue_slice_membership(i, slice_id))
        continue;


      UE_id = i;

      for (n = 0; n < UE_list->numactiveULCCs[UE_id]; n++) {
        // This is the actual CC_id in the list
        CC_id = UE_list->ordered_ULCCids[n][UE_id];
        UE_template = &UE_list->UE_template[CC_id][UE_id];
        harq_pid = subframe2harqpid(&RC.mac[module_idP]->common_channels[CC_id],
                                    frameP, sched_subframeP);

        //      mac_xface->get_ue_active_harq_pid(module_idP,CC_id,rnti,frameP,subframeP,&harq_pid,&round,openair_harq_UL);

        if (UE_list->UE_sched_ctrl[UE_id].round_UL[CC_id] > 0) {
          nb_allocated_rbs[CC_id][UE_id] = UE_list->UE_template[CC_id][UE_id].nb_rb_ul[harq_pid];
        } else {
          nb_allocated_rbs[CC_id][UE_id] =
                  cmin(UE_list->UE_template[CC_id][UE_id].pre_allocated_nb_rb_ul[slice_id],
                       average_rbs_per_user[CC_id]);
        }

        total_allocated_rbs[CC_id] += nb_allocated_rbs[CC_id][UE_id];
        LOG_D(MAC,
              "In ulsch_preprocessor: assigning %d RBs for UE %d/%x CCid %d, harq_pid %d\n",
              nb_allocated_rbs[CC_id][UE_id], UE_id, rnti, CC_id,
              harq_pid);
      }
    }

    // step 4: assigne the remaining RBs and set the pre_allocated rbs accordingly
  for (r = 0; r < 2; r++) {

    for (i = UE_list->head_ul; i >= 0; i = UE_list->next_ul[i]) {
      rnti = UE_RNTI(module_idP, i);

      if (rnti == NOT_A_RNTI)
        continue;
      if (UE_list->UE_sched_ctrl[i].ul_out_of_sync == 1)
        continue;
      if (!ue_slice_membership(i, slice_id))
        continue;

      UE_id = i;
      ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];

      for (n = 0; n < UE_list->numactiveULCCs[UE_id]; n++) {
        // This is the actual CC_id in the list
        CC_id = UE_list->ordered_ULCCids[n][UE_id];
        UE_template = &UE_list->UE_template[CC_id][UE_id];
        total_remaining_rbs[CC_id] =
                ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id] - total_allocated_rbs[CC_id];

        if (total_ue_count[CC_id] == 1) {
          total_remaining_rbs[CC_id] += 1;
        }

        if (r == 0) {
          while ((UE_template->pre_allocated_nb_rb_ul[slice_id] > 0)
                 && (nb_allocated_rbs[CC_id][UE_id] < UE_template->pre_allocated_nb_rb_ul[slice_id])
                 && (total_remaining_rbs[CC_id] > 0)) {
            nb_allocated_rbs[CC_id][UE_id] =
                    cmin(nb_allocated_rbs[CC_id][UE_id] + 1,
                         UE_template->pre_allocated_nb_rb_ul[slice_id]);
            total_remaining_rbs[CC_id]--;
            total_allocated_rbs[CC_id]++;
          }
        } else {
          UE_template->pre_allocated_nb_rb_ul[slice_id] =
                  nb_allocated_rbs[CC_id][UE_id];
          LOG_D(MAC,
                "******************UL Scheduling Information for UE%d CC_id %d ************************\n",
                UE_id, CC_id);
          LOG_D(MAC,
                "[eNB %d] total RB allocated for UE%d CC_id %d  = %d\n",
                module_idP, UE_id, CC_id,
                UE_template->pre_allocated_nb_rb_ul[slice_id]);
        }
      }
    }
  }
}

void
assign_max_mcs_min_rb(module_id_t module_idP, int slice_id, int frameP,
		      sub_frame_t subframeP, uint16_t * first_rb)
{

  int i;
  uint16_t n, UE_id;
  uint8_t CC_id;
  rnti_t rnti = -1;
  int mcs;
  int rb_table_index = 0, tbs, tx_power;
  eNB_MAC_INST *eNB = RC.mac[module_idP];
  UE_list_t *UE_list = &eNB->UE_list;

  UE_TEMPLATE *UE_template;
  UE_sched_ctrl *ue_sched_ctl;
  int Ncp;
  int N_RB_UL;

  for (i = 0; i < MAX_MOBILES_PER_ENB; i++) {
    if (UE_list->active[i] != TRUE)
      continue;

    rnti = UE_RNTI(module_idP, i);

    if (rnti == NOT_A_RNTI)
      continue;
    if (UE_list->UE_sched_ctrl[i].ul_out_of_sync == 1)
      continue;
    if (!ue_slice_membership(i, slice_id))
      continue;

    if (UE_list->UE_sched_ctrl[i].phr_received == 1) {
      /* if we've received the power headroom information the UE, we can go to
       * maximum mcs */
      mcs = cmin(20, slice_maxmcs_uplink[slice_id]);
    } else {
      /* otherwise, limit to QPSK PUSCH */
      mcs = cmin(10, slice_maxmcs_uplink[slice_id]);
    }

    UE_id = i;

    for (n = 0; n < UE_list->numactiveULCCs[UE_id]; n++) {
      // This is the actual CC_id in the list
      CC_id = UE_list->ordered_ULCCids[n][UE_id];



      AssertFatal(CC_id < RC.nb_mac_CC[module_idP],
                  "CC_id %u should be < %u, loop n=%u < numactiveULCCs[%u]=%u",
                  CC_id, NFAPI_CC_MAX, n, UE_id,
                  UE_list->numactiveULCCs[UE_id]);

      UE_template = &UE_list->UE_template[CC_id][UE_id];
      UE_template->pre_assigned_mcs_ul = mcs;
      ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];

      Ncp = RC.mac[module_idP]->common_channels[CC_id].Ncp;
      N_RB_UL = to_prb(RC.mac[module_idP]->common_channels[CC_id].ul_Bandwidth);
      ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] = flexran_nb_rbs_allowed_slice(slice_percentage_uplink[slice_id],N_RB_UL);

      int bytes_to_schedule = UE_template->estimated_ul_buffer - UE_template->scheduled_ul_bytes;
      if (bytes_to_schedule < 0) bytes_to_schedule = 0;
      int bits_to_schedule = bytes_to_schedule * 8;

      // if this UE has UL traffic
      if (bits_to_schedule > 0) {
        tbs = get_TBS_UL(UE_template->pre_assigned_mcs_ul, 3) << 3; // 1 or 2 PRB with cqi enabled does not work well!
        rb_table_index = 2;

        // fixme: set use_srs flag
        tx_power = estimate_ue_tx_power(tbs, rb_table[rb_table_index], 0, Ncp, 0);

        while ((((UE_template->phr_info - tx_power) < 0)
              || (tbs > bits_to_schedule))
              && (UE_template->pre_assigned_mcs_ul > 3)) {
          // LOG_I(MAC,"UE_template->phr_info %d tx_power %d mcs %d\n", UE_template->phr_info,tx_power, mcs);
          UE_template->pre_assigned_mcs_ul--;
          tbs = get_TBS_UL(UE_template->pre_assigned_mcs_ul, rb_table[rb_table_index]) << 3;
          tx_power = estimate_ue_tx_power(tbs, rb_table[rb_table_index], 0, Ncp, 0);   // fixme: set use_srs
        }

        while ((tbs < bits_to_schedule)
                && (rb_table[rb_table_index] < (ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id]))
                && ((UE_template->phr_info - tx_power) > 0)
                && (rb_table_index < 32)) {
          rb_table_index++;
          tbs = get_TBS_UL(UE_template->pre_assigned_mcs_ul, rb_table[rb_table_index]) << 3;
          tx_power = estimate_ue_tx_power(tbs, rb_table[rb_table_index], 0, Ncp, 0);
        }

        UE_template->ue_tx_power = tx_power;

        if (rb_table[rb_table_index] > (ue_sched_ctl->max_rbs_allowed_slice_uplink[CC_id][slice_id] - first_rb[CC_id] - 1)) {
          rb_table_index--;
        }
        // 1 or 2 PRB with cqi enabled does not work well
        if (rb_table[rb_table_index] < 3) {
            rb_table_index = 2;	//3PRB
        }

        UE_template->pre_allocated_rb_table_index_ul = rb_table_index;
        UE_template->pre_allocated_nb_rb_ul[slice_id] = rb_table[rb_table_index];
        LOG_D(MAC,
              "[eNB %d] frame %d subframe %d: for UE %d CC %d: pre-assigned mcs %d, pre-allocated rb_table[%d]=%d RBs (phr %d, tx power %d)\n",
              module_idP, frameP, subframeP, UE_id, CC_id,
              UE_template->pre_assigned_mcs_ul,
              UE_template->pre_allocated_rb_table_index_ul,
              UE_template->pre_allocated_nb_rb_ul[slice_id],
              UE_template->phr_info, tx_power);
      } else {
        /* if UE has pending scheduling request then pre-allocate 3 RBs */
        //if (UE_template->ul_active == 1 && UE_template->ul_SR == 1) {
        if (UE_is_to_be_scheduled(module_idP, CC_id, i)) {
          /* use QPSK mcs */
          UE_template->pre_assigned_mcs_ul = 10;
          UE_template->pre_allocated_rb_table_index_ul = 2;
          UE_template->pre_allocated_nb_rb_ul[slice_id] = 3;
        } else {
          UE_template->pre_assigned_mcs_ul = 0;
          UE_template->pre_allocated_rb_table_index_ul = -1;
          UE_template->pre_allocated_nb_rb_ul[slice_id] = 0;
        }
      }
    }
  }
}

struct sort_ue_ul_params {
    int module_idP;
    int frameP;
    int subframeP;
};

static int ue_ul_compare(const void *_a, const void *_b, void *_params)
{
    struct sort_ue_ul_params *params = _params;
    UE_list_t *UE_list = &RC.mac[params->module_idP]->UE_list;

    int UE_id1 = *(const int *) _a;
    int UE_id2 = *(const int *) _b;

    int rnti1 = UE_RNTI(params->module_idP, UE_id1);
    int pCCid1 = UE_PCCID(params->module_idP, UE_id1);
    int round1 = maxround(params->module_idP, rnti1, params->frameP,
			  params->subframeP, 1);

    int rnti2 = UE_RNTI(params->module_idP, UE_id2);
    int pCCid2 = UE_PCCID(params->module_idP, UE_id2);
    int round2 = maxround(params->module_idP, rnti2, params->frameP,
			  params->subframeP, 1);

    if (round1 > round2)
	return -1;
    if (round1 < round2)
	return 1;

    if (UE_list->UE_template[pCCid1][UE_id1].ul_buffer_info[LCGID0] >
	UE_list->UE_template[pCCid2][UE_id2].ul_buffer_info[LCGID0])
	return -1;
    if (UE_list->UE_template[pCCid1][UE_id1].ul_buffer_info[LCGID0] <
	UE_list->UE_template[pCCid2][UE_id2].ul_buffer_info[LCGID0])
	return 1;

    int bytes_to_schedule1 = UE_list->UE_template[pCCid1][UE_id1].estimated_ul_buffer - UE_list->UE_template[pCCid1][UE_id1].scheduled_ul_bytes;
    if (bytes_to_schedule1 < 0) bytes_to_schedule1 = 0;
    int bytes_to_schedule2 = UE_list->UE_template[pCCid2][UE_id2].estimated_ul_buffer - UE_list->UE_template[pCCid2][UE_id2].scheduled_ul_bytes;
    if (bytes_to_schedule2 < 0) bytes_to_schedule2 = 0;

    if (bytes_to_schedule1 > bytes_to_schedule2)
	return -1;
    if (bytes_to_schedule1 < bytes_to_schedule2)
	return 1;

    if (UE_list->UE_template[pCCid1][UE_id1].pre_assigned_mcs_ul >
	UE_list->UE_template[pCCid2][UE_id2].pre_assigned_mcs_ul)
	return -1;
    if (UE_list->UE_template[pCCid1][UE_id1].pre_assigned_mcs_ul <
	UE_list->UE_template[pCCid2][UE_id2].pre_assigned_mcs_ul)
	return 1;

    return 0;
}

void sort_ue_ul(module_id_t module_idP, int frameP, sub_frame_t subframeP)
{
    int i;
    int list[MAX_MOBILES_PER_ENB];
    int list_size = 0;
    int rnti;
    struct sort_ue_ul_params params = { module_idP, frameP, subframeP };

    UE_list_t *UE_list = &RC.mac[module_idP]->UE_list;

    for (i = 0; i < MAX_MOBILES_PER_ENB; i++) {
	if (UE_list->active[i] == FALSE)
	    continue;
	if ((rnti = UE_RNTI(module_idP, i)) == NOT_A_RNTI)
	    continue;
	if (UE_list->UE_sched_ctrl[i].ul_out_of_sync == 1)
	    continue;

	list[list_size] = i;
	list_size++;
    }

    qsort_r(list, list_size, sizeof(int), ue_ul_compare, &params);

    if (list_size) {
	for (i = 0; i < list_size - 1; i++)
	    UE_list->next_ul[list[i]] = list[i + 1];
	UE_list->next_ul[list[list_size - 1]] = -1;
	UE_list->head_ul = list[0];
    } else {
	UE_list->head_ul = -1;
    }
}
