eNB_scheduler_ulsch.c

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/*! \file eNB_scheduler_ulsch.c
 * \brief eNB procedures for the ULSCH transport channel
 * \author Navid Nikaein and Raymond Knopp
 * \date 2010 - 2014
 * \email: navid.nikaein@eurecom.fr
 * \version 1.0
 * @ingroup _mac

 */

#include "assertions.h"
#include "PHY/defs.h"
#include "PHY/extern.h"

#include "SCHED/defs.h"
#include "SCHED/extern.h"

#include "LAYER2/MAC/defs.h"
#include "LAYER2/MAC/proto.h"
#include "LAYER2/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/LITE/extern.h"
#include "RRC/L2_INTERFACE/openair_rrc_L2_interface.h"

//#include "LAYER2/MAC/pre_processor.c"
#include "pdcp.h"

#if defined(ENABLE_ITTI)
# include "intertask_interface.h"
#endif

#define ENABLE_MAC_PAYLOAD_DEBUG
#define DEBUG_eNB_SCHEDULER 1

// This table holds the allowable PRB sizes for ULSCH transmissions
uint8_t rb_table[33] = {1,2,3,4,5,6,8,9,10,12,15,16,18,20,24,25,27,30,32,36,40,45,48,50,54,60,72,75,80,81,90,96,100};

void rx_sdu(
  const module_id_t enb_mod_idP,
  const int         CC_idP,
  const frame_t     frameP,
  const sub_frame_t subframeP,
  const rnti_t      rntiP,
  uint8_t          *sduP,
  const uint16_t    sdu_lenP,
  const int         harq_pidP,
  uint8_t          *msg3_flagP)
{

  unsigned char  rx_ces[MAX_NUM_CE],num_ce,num_sdu,i,*payload_ptr;
  unsigned char  rx_lcids[NB_RB_MAX];
  unsigned short rx_lengths[NB_RB_MAX];
  int    UE_id = find_UE_id(enb_mod_idP,rntiP);
  int ii,j;
  eNB_MAC_INST *eNB = &eNB_mac_inst[enb_mod_idP];
  UE_list_t *UE_list= &eNB->UE_list;

  start_meas(&eNB->rx_ulsch_sdu);

  if ((UE_id >  NUMBER_OF_UE_MAX) || (UE_id == -1)  )
    for(ii=0; ii<NB_RB_MAX; ii++) {
      rx_lengths[ii] = 0;
    }

  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_RX_SDU,1);
  if (opt_enabled == 1) {
    trace_pdu(0, sduP,sdu_lenP, 0, 3, rntiP,subframeP, 0,0);
    LOG_D(OPT,"[eNB %d][ULSCH] Frame %d  rnti %x  with size %d\n",
    		  enb_mod_idP, frameP, rntiP, sdu_lenP);
  }

  LOG_D(MAC,"[eNB %d] CC_id %d Received ULSCH sdu from PHY (rnti %x, UE_id %d), parsing header\n",enb_mod_idP,CC_idP,rntiP,UE_id);
  
  payload_ptr = parse_ulsch_header(sduP,&num_ce,&num_sdu,rx_ces,rx_lcids,rx_lengths,sdu_lenP);
 
  eNB->eNB_stats[CC_idP].ulsch_bytes_rx=sdu_lenP;
  eNB->eNB_stats[CC_idP].total_ulsch_bytes_rx+=sdu_lenP;
  eNB->eNB_stats[CC_idP].total_ulsch_pdus_rx+=1;
  // control element
  for (i=0; i<num_ce; i++) {

    switch (rx_ces[i]) { // implement and process BSR + CRNTI +
    case POWER_HEADROOM:
      if (UE_id != -1) {
        UE_list->UE_template[CC_idP][UE_id].phr_info =  (payload_ptr[0] & 0x3f) - PHR_MAPPING_OFFSET;
        LOG_D(MAC, "[eNB %d] CC_id %d MAC CE_LCID %d : Received PHR PH = %d (db)\n",
              enb_mod_idP, CC_idP, rx_ces[i], UE_list->UE_template[CC_idP][UE_id].phr_info);
        UE_list->UE_template[CC_idP][UE_id].phr_info_configured=1;
      }

      payload_ptr+=sizeof(POWER_HEADROOM_CMD);
      break;

    case CRNTI:
      LOG_D(MAC, "[eNB %d] CC_id %d MAC CE_LCID %d (ce %d/%d): Received CRNTI %2.2x%2.2x\n",
            enb_mod_idP, CC_idP, rx_ces[i], i,num_ce, payload_ptr[0], payload_ptr[1]);
      UE_id = find_UE_id(enb_mod_idP,(((uint16_t)payload_ptr[0])<<8) + payload_ptr[1]);
      LOG_I(MAC, "[eNB %d] CC_id %d MAC CE_LCID %d : CRNTI %x (UE_id %d) in Msg3\n",enb_mod_idP, CC_idP, rx_ces[i], (((uint16_t)payload_ptr[0])<<8) + payload_ptr[1],UE_id);

      payload_ptr+=2;
      /* we don't process this CE yet */
      if (msg3_flagP != NULL) {
	*msg3_flagP = 0;
      }
      break;

    case TRUNCATED_BSR:
    case SHORT_BSR: {
      uint8_t lcgid;
      lcgid = (payload_ptr[0] >> 6);

      LOG_D(MAC, "[eNB %d] CC_id %d MAC CE_LCID %d : Received short BSR LCGID = %u bsr = %d\n",
	    enb_mod_idP, CC_idP, rx_ces[i], lcgid, payload_ptr[0] & 0x3f);

      if (UE_id  != -1) {

        UE_list->UE_template[CC_idP][UE_id].bsr_info[lcgid] = (payload_ptr[0] & 0x3f);

        if (UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[lcgid] == 0 ) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[lcgid]=frameP;
        }
      }
      else {

      }
      payload_ptr += 1;//sizeof(SHORT_BSR); // fixme
    }
    break;

    case LONG_BSR:
      if (UE_id  != -1) {
        UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID0] = ((payload_ptr[0] & 0xFC) >> 2);
        UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID1] =
          ((payload_ptr[0] & 0x03) << 4) | ((payload_ptr[1] & 0xF0) >> 4);
        UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID2] =
          ((payload_ptr[1] & 0x0F) << 2) | ((payload_ptr[2] & 0xC0) >> 6);
        UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID3] = (payload_ptr[2] & 0x3F);
        LOG_D(MAC, "[eNB %d] CC_id %d MAC CE_LCID %d: Received long BSR LCGID0 = %u LCGID1 = "
              "%u LCGID2 = %u LCGID3 = %u\n",
              enb_mod_idP, CC_idP,
              rx_ces[i],
              UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID0],
              UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID1],
              UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID2],
              UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID3]);

        if (UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID0] == 0 ) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID0]=0;
        } else if (UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID0] == 0) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID0]=frameP;
        }

        if (UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID1] == 0 ) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID1]=0;
        } else if (UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID1] == 0) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID1]=frameP;
        }

        if (UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID2] == 0 ) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID2]=0;
        } else if (UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID2] == 0) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID2]=frameP;
        }

        if (UE_list->UE_template[CC_idP][UE_id].bsr_info[LCGID3] == 0 ) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID3]= 0;
        } else if (UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID3] == 0) {
          UE_list->UE_template[CC_idP][UE_id].ul_buffer_creation_time[LCGID3]=frameP;

        }
      }

      payload_ptr += 3;////sizeof(LONG_BSR);
      break;

    default:
      LOG_E(MAC, "[eNB %d] CC_id %d Received unknown MAC header (0x%02x)\n", enb_mod_idP, CC_idP, rx_ces[i]);
      break;
    }
  }

  for (i=0; i<num_sdu; i++) {
    LOG_D(MAC,"SDU Number %d MAC Subheader SDU_LCID %d, length %d\n",i,rx_lcids[i],rx_lengths[i]);

    switch (rx_lcids[i]) {
    case CCCH :
      LOG_I(MAC,"[eNB %d][RAPROC] CC_id %d Frame %d, Received CCCH:  %x.%x.%x.%x.%x.%x, Terminating RA procedure for UE rnti %x\n",
            enb_mod_idP,CC_idP,frameP,
            payload_ptr[0],payload_ptr[1],payload_ptr[2],payload_ptr[3],payload_ptr[4], payload_ptr[5], rntiP);

      for (ii=0; ii<NB_RA_PROC_MAX; ii++) {
        LOG_D(MAC,"[eNB %d][RAPROC] CC_id %p Checking proc %d : rnti (%x, %x), active %d\n",
              enb_mod_idP, CC_idP, ii,
              eNB->common_channels[CC_idP].RA_template[ii].rnti, rntiP,
              eNB->common_channels[CC_idP].RA_template[ii].RA_active);

        if ((eNB->common_channels[CC_idP].RA_template[ii].rnti==rntiP) &&
            (eNB->common_channels[CC_idP].RA_template[ii].RA_active==TRUE)) {

          //payload_ptr = parse_ulsch_header(msg3,&num_ce,&num_sdu,rx_ces,rx_lcids,rx_lengths,msg3_len);

          if (UE_id < 0) {
            memcpy(&eNB->common_channels[CC_idP].RA_template[ii].cont_res_id[0],payload_ptr,6);
            LOG_I(MAC,"[eNB %d][RAPROC] CC_id %d Frame %d CCCH: Received Msg3: length %d, offset %d\n",
                  enb_mod_idP,CC_idP,frameP,rx_lengths[ii],payload_ptr-sduP);

            if ((UE_id=add_new_ue(enb_mod_idP,CC_idP,eNB->common_channels[CC_idP].RA_template[ii].rnti,harq_pidP)) == -1 ) {
              mac_xface->macphy_exit("[MAC][eNB] Max user count reached\n");
	      // kill RA procedure
            } else
              LOG_I(MAC,"[eNB %d][RAPROC] CC_id %d Frame %d Added user with rnti %x => UE %d\n",
                    enb_mod_idP,CC_idP,frameP,eNB->common_channels[CC_idP].RA_template[ii].rnti,UE_id);
          } else {
            LOG_I(MAC,"[eNB %d][RAPROC] CC_id %d Frame %d CCCH: Received Msg3 from already registered UE %d: length %d, offset %d\n",
                  enb_mod_idP,CC_idP,frameP,UE_id,rx_lengths[ii],payload_ptr-sduP);
	    // kill RA procedure
          }

          if (Is_rrc_registered == 1)
            mac_rrc_data_ind(
              enb_mod_idP,
              CC_idP,
              frameP,subframeP,
              rntiP,
              CCCH,
              (uint8_t*)payload_ptr,
              rx_lengths[ii],
              ENB_FLAG_YES,
              enb_mod_idP,
              0);


          if (num_ce >0) {  // handle msg3 which is not RRCConnectionRequest
            //  process_ra_message(msg3,num_ce,rx_lcids,rx_ces);
          }

          eNB->common_channels[CC_idP].RA_template[ii].generate_Msg4 = 1;
          eNB->common_channels[CC_idP].RA_template[ii].wait_ack_Msg4 = 0;

        } // if process is active
      } // loop on RA processes

      break;

    case  DCCH :
    case DCCH1 :
      //      if(eNB_mac_inst[module_idP][CC_idP].Dcch_lchan[UE_id].Active==1){

#if defined(ENABLE_MAC_PAYLOAD_DEBUG)
      LOG_T(MAC,"offset: %d\n",(unsigned char)((unsigned char*)payload_ptr-sduP));

      for (j=0; j<32; j++) {
        LOG_T(MAC,"%x ",payload_ptr[j]);
      }

      LOG_T(MAC,"\n");
#endif

      if (UE_id != -1) {
        //  This check is just to make sure we didn't get a bogus SDU length, to be removed ...
        if (rx_lengths[i]<CCCH_PAYLOAD_SIZE_MAX) {
          LOG_D(MAC,"[eNB %d] CC_id %d Frame %d : ULSCH -> UL-DCCH, received %d bytes form UE %d on LCID %d \n",
                enb_mod_idP,CC_idP,frameP, rx_lengths[i], UE_id, rx_lcids[i]);

          mac_rlc_data_ind(
            enb_mod_idP,
            rntiP,
	      enb_mod_idP,
            frameP,
            ENB_FLAG_YES,
            MBMS_FLAG_NO,
            rx_lcids[i],
            (char *)payload_ptr,
            rx_lengths[i],
            1,
            NULL);//(unsigned int*)crc_status);
          UE_list->eNB_UE_stats[CC_idP][UE_id].num_pdu_rx[rx_lcids[i]]+=1;
          UE_list->eNB_UE_stats[CC_idP][UE_id].num_bytes_rx[rx_lcids[i]]+=rx_lengths[i];
        }
      } /* UE_id != -1 */

      //      }
      break;

    case DTCH: // default DRB
      //      if(eNB_mac_inst[module_idP][CC_idP].Dcch_lchan[UE_id].Active==1){

#if defined(ENABLE_MAC_PAYLOAD_DEBUG)
      LOG_T(MAC,"offset: %d\n",(unsigned char)((unsigned char*)payload_ptr-sduP));

      for (j=0; j<32; j++) {
        LOG_T(MAC,"%x ",payload_ptr[j]);
      }

      LOG_T(MAC,"\n");
#endif

      LOG_D(MAC,"[eNB %d] CC_id %d Frame %d : ULSCH -> UL-DTCH, received %d bytes from UE %d for lcid %d\n",
            enb_mod_idP,CC_idP,frameP, rx_lengths[i], UE_id,rx_lcids[i]);

      if (UE_id != -1) {
        if ((rx_lengths[i] <SCH_PAYLOAD_SIZE_MAX) &&  (rx_lengths[i] > 0) ) {   // MAX SIZE OF transport block
          mac_rlc_data_ind(
            enb_mod_idP,
            rntiP,
            enb_mod_idP,
            frameP,
            ENB_FLAG_YES,
            MBMS_FLAG_NO,
            DTCH,
            (char *)payload_ptr,
            rx_lengths[i],
            1,
            NULL);//(unsigned int*)crc_status);
          UE_list->eNB_UE_stats[CC_idP][UE_id].num_pdu_rx[rx_lcids[i]]+=1;
          UE_list->eNB_UE_stats[CC_idP][UE_id].num_bytes_rx[rx_lcids[i]]+=rx_lengths[i];
        }
      } /* UE_id != -1 */

      //      }
      break;

    default :  //if (rx_lcids[i] >= DTCH) {
      if (UE_id != -1)
        UE_list->eNB_UE_stats[CC_idP][UE_id].num_errors_rx+=1;
      LOG_E(MAC,"[eNB %d] CC_id %d Frame %d : received unsupported or unknown LCID %d from UE %d ",
            enb_mod_idP, CC_idP, frameP, rx_lcids[i], UE_id);
      break;
    }

    payload_ptr+=rx_lengths[i];
  }

  /* NN--> FK: we could either check the payload, or use a phy helper to detect a false msg3 */
  if ((num_sdu == 0) && (num_ce==0)) {
    if (UE_id != -1)
      UE_list->eNB_UE_stats[CC_idP][UE_id].total_num_errors_rx+=1;

    if (msg3_flagP != NULL) {
      if( *msg3_flagP == 1 ) {
        LOG_N(MAC,"[eNB %d] CC_id %d frame %d : false msg3 detection: signal phy to canceling RA and remove the UE\n", enb_mod_idP, CC_idP, frameP);
        *msg3_flagP=0;
      }
    }
  } else {
    if (UE_id != -1) {
      UE_list->eNB_UE_stats[CC_idP][UE_id].pdu_bytes_rx=sdu_lenP;
      UE_list->eNB_UE_stats[CC_idP][UE_id].total_pdu_bytes_rx+=sdu_lenP;
      UE_list->eNB_UE_stats[CC_idP][UE_id].total_num_pdus_rx+=1;
    }
  }

  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_RX_SDU,0);
  stop_meas(&eNB->rx_ulsch_sdu);
}


uint32_t bytes_to_bsr_index(int32_t nbytes)
{

  uint32_t i=0;

  if (nbytes<0) {
    return(0);
  }

  while ((i<BSR_TABLE_SIZE)&&
         (BSR_TABLE[i]<=nbytes)) {
    i++;
  }

  return(i-1);
}

void adjust_bsr_info(int buffer_occupancy,
                     uint16_t TBS,
                     UE_TEMPLATE *UE_template)
{

  uint32_t         tmp_bsr;

  // could not serve all the uplink traffic
  if (buffer_occupancy > 0 ) {
    if (BSR_TABLE[UE_template->bsr_info[LCGID0]] <=  TBS ) {
      tmp_bsr = BSR_TABLE[UE_template->bsr_info[LCGID0]]; // serving this amout of  bytes
      UE_template->bsr_info[LCGID0] = 0;

      if (BSR_TABLE[UE_template->bsr_info[LCGID1]] <= (TBS-tmp_bsr)) {
        tmp_bsr += BSR_TABLE[UE_template->bsr_info[LCGID1]];
        UE_template->bsr_info[LCGID1] = 0;

        if (BSR_TABLE[UE_template->bsr_info[LCGID2]] <= (TBS-tmp_bsr)) {
          tmp_bsr += BSR_TABLE[UE_template->bsr_info[LCGID2]];
          UE_template->bsr_info[LCGID2] = 0;

          if (BSR_TABLE[UE_template->bsr_info[LCGID3]] <= (TBS-tmp_bsr)) {
            tmp_bsr += BSR_TABLE[UE_template->bsr_info[LCGID3]];
            UE_template->bsr_info[LCGID3] = 0;
          } else {
            UE_template->bsr_info[LCGID3] = bytes_to_bsr_index((int32_t)BSR_TABLE[UE_template->bsr_info[LCGID3]] - ((int32_t) TBS - (int32_t)tmp_bsr));
          }
        } else {
          UE_template->bsr_info[LCGID2] = bytes_to_bsr_index((int32_t)BSR_TABLE[UE_template->bsr_info[LCGID2]] - ((int32_t)TBS - (int32_t)tmp_bsr));
        }
      } else {
        UE_template->bsr_info[LCGID1] = bytes_to_bsr_index((int32_t)BSR_TABLE[UE_template->bsr_info[LCGID1]] - ((int32_t)TBS - (int32_t)tmp_bsr));
      }
    } else {
      UE_template->bsr_info[LCGID0] = bytes_to_bsr_index((int32_t)BSR_TABLE[UE_template->bsr_info[LCGID0]] - (int32_t)TBS);
    }
  } else { // we have flushed all buffers so clear bsr
    UE_template->bsr_info[LCGID0] = 0;
    UE_template->bsr_info[LCGID1] = 0;
    UE_template->bsr_info[LCGID2] = 0;
    UE_template->bsr_info[LCGID3] = 0;
  }


}

void add_ue_ulsch_info(module_id_t module_idP, int CC_id, int UE_id, sub_frame_t subframeP, UE_ULSCH_STATUS status)
{

  eNB_ulsch_info[module_idP][CC_id][UE_id].rnti             = UE_RNTI(module_idP,UE_id);
  eNB_ulsch_info[module_idP][CC_id][UE_id].subframe         = subframeP;
  eNB_ulsch_info[module_idP][CC_id][UE_id].status           = status;

  eNB_ulsch_info[module_idP][CC_id][UE_id].serving_num++;

}

// This seems not to be used anymore
/*
int schedule_next_ulue(module_id_t module_idP, int UE_id, sub_frame_t subframeP){

  int next_ue;

  // first phase: scheduling for ACK
  switch (subframeP) {
    // scheduling for subframeP 2: for scheduled user during subframeP 5 and 6
  case 8:
    if  ((eNB_dlsch_info[module_idP][UE_id].status == S_DL_SCHEDULED) &&
   (eNB_dlsch_info[module_idP][UE_id].subframe == 5 || eNB_dlsch_info[module_idP][UE_id].subframe == 6)){
      // set the downlink status
      eNB_dlsch_info[module_idP][UE_id].status = S_DL_BUFFERED;
      return UE_id;
    }
    break;
    // scheduling for subframeP 3: for scheduled user during subframeP 7 and 8
  case 9:
    if  ((eNB_dlsch_info[module_idP][UE_id].status == S_DL_SCHEDULED) &&
   (eNB_dlsch_info[module_idP][UE_id].subframe == 7 || eNB_dlsch_info[module_idP][UE_id].subframe == 8)){
      eNB_dlsch_info[module_idP][UE_id].status = S_DL_BUFFERED;
      return UE_id;
    }
    break;
    // scheduling UL subframeP 4: for scheduled user during subframeP 9 and 0
  case 0 :
    if  ((eNB_dlsch_info[module_idP][UE_id].status == S_DL_SCHEDULED) &&
   (eNB_dlsch_info[module_idP][UE_id].subframe == 9 || eNB_dlsch_info[module_idP][UE_id].subframe == 0)){
      eNB_dlsch_info[module_idP][UE_id].status = S_DL_BUFFERED;
      return UE_id;
    }
    break;
  default:
    break;
  }

  // second phase
  for (next_ue=0; next_ue <NUMBER_OF_UE_MAX; next_ue++ ){

    if  (eNB_ulsch_info[module_idP][next_ue].status == S_UL_WAITING )
      return next_ue;
    else if (eNB_ulsch_info[module_idP][next_ue].status == S_UL_SCHEDULED){
      eNB_ulsch_info[module_idP][next_ue].status = S_UL_BUFFERED;
    }
  }
  for (next_ue=0; next_ue <NUMBER_OF_UE_MAX; next_ue++ ){
    if (eNB_ulsch_info[module_idP][next_ue].status != S_UL_NONE )// do this just for active UEs
      eNB_ulsch_info[module_idP][next_ue].status = S_UL_WAITING;
  }
  next_ue = 0;
  return next_ue;

}
 */





unsigned char *parse_ulsch_header(unsigned char *mac_header,
                                  unsigned char *num_ce,
                                  unsigned char *num_sdu,
                                  unsigned char *rx_ces,
                                  unsigned char *rx_lcids,
                                  unsigned short *rx_lengths,
                                  unsigned short tb_length)
{

  unsigned char not_done=1,num_ces=0,num_sdus=0,lcid,num_sdu_cnt;
  unsigned char *mac_header_ptr = mac_header;
  unsigned short length, ce_len=0;

  while (not_done==1) {

    if (((SCH_SUBHEADER_FIXED*)mac_header_ptr)->E == 0) {
      not_done = 0;
    }

    lcid = ((SCH_SUBHEADER_FIXED *)mac_header_ptr)->LCID;

    if (lcid < EXTENDED_POWER_HEADROOM) {
      if (not_done==0) { // last MAC SDU, length is implicit
        mac_header_ptr++;
        length = tb_length-(mac_header_ptr-mac_header)-ce_len;

        for (num_sdu_cnt=0; num_sdu_cnt < num_sdus ; num_sdu_cnt++) {
          length -= rx_lengths[num_sdu_cnt];
        }
      } else {
        if (((SCH_SUBHEADER_SHORT *)mac_header_ptr)->F == 0) {
          length = ((SCH_SUBHEADER_SHORT *)mac_header_ptr)->L;
          mac_header_ptr += 2;//sizeof(SCH_SUBHEADER_SHORT);
        } else { // F = 1
          length = ((((SCH_SUBHEADER_LONG *)mac_header_ptr)->L_MSB & 0x7f ) << 8 ) | (((SCH_SUBHEADER_LONG *)mac_header_ptr)->L_LSB & 0xff);
          mac_header_ptr += 3;//sizeof(SCH_SUBHEADER_LONG);
        }
      }

      LOG_D(MAC,"[eNB] sdu %d lcid %d tb_length %d length %d (offset now %d)\n",
            num_sdus,lcid,tb_length, length,mac_header_ptr-mac_header);
      rx_lcids[num_sdus] = lcid;
      rx_lengths[num_sdus] = length;
      num_sdus++;
    } else { // This is a control element subheader POWER_HEADROOM, BSR and CRNTI
      if (lcid == SHORT_PADDING) {
        mac_header_ptr++;
      } else {
        rx_ces[num_ces] = lcid;
        num_ces++;
        mac_header_ptr++;

        if (lcid==LONG_BSR) {
          ce_len+=3;
        } else if (lcid==CRNTI) {
          ce_len+=2;
        } else if ((lcid==POWER_HEADROOM) || (lcid==TRUNCATED_BSR)|| (lcid== SHORT_BSR)) {
          ce_len++;
        } else {
          LOG_E(MAC,"unknown CE %d \n", lcid);
          mac_xface->macphy_exit("unknown CE");
        }
      }
    }
  }

  *num_ce = num_ces;
  *num_sdu = num_sdus;

  return(mac_header_ptr);
}


void schedule_ulsch(module_id_t module_idP, frame_t frameP,unsigned char cooperation_flag,sub_frame_t subframeP, unsigned char sched_subframe,
                    unsigned int *nCCE)  //,int calibration_flag) {
{


  unsigned int nCCE_available[MAX_NUM_CCs];
  uint16_t first_rb[MAX_NUM_CCs],i;
  int CC_id;
  eNB_MAC_INST *eNB=&eNB_mac_inst[module_idP];

  start_meas(&eNB->schedule_ulsch);


  for (CC_id=0; CC_id<MAX_NUM_CCs; CC_id++) {

    first_rb[CC_id] = 1;
    nCCE_available[CC_id] = mac_xface->get_nCCE_max(module_idP,CC_id) - nCCE[CC_id];

    // UE data info;
    // check which UE has data to transmit
    // function to decide the scheduling
    // e.g. scheduling_rslt = Greedy(granted_UEs, nb_RB)

    // default function for default scheduling
    //

    // output of scheduling, the UE numbers in RBs, where it is in the code???
    // check if RA (Msg3) is active in this subframeP, if so skip the PRBs used for Msg3
    // Msg3 is using 1 PRB so we need to increase first_rb accordingly
    // not sure about the break (can there be more than 1 active RA procedure?)

    for (i=0; i<NB_RA_PROC_MAX; i++) {
      if ((eNB->common_channels[CC_id].RA_template[i].RA_active == TRUE) &&
          (eNB->common_channels[CC_id].RA_template[i].generate_rar == 0) &&
          (eNB->common_channels[CC_id].RA_template[i].Msg3_subframe == sched_subframe)) {
	//leave out first RB for PUCCH
        first_rb[CC_id]++;
        break;
      }
    }

    /*
    if (mac_xface->is_prach_subframe(&(mac_xface->lte_frame_parms),frameP,subframeP)) {
      first_rb[CC_id] = (mac_xface->get_prach_prb_offset(&(mac_xface->lte_frame_parms),
    */

  }

  schedule_ulsch_rnti(module_idP, cooperation_flag, frameP, subframeP, sched_subframe, nCCE, nCCE_available, first_rb);

#ifdef CBA
  schedule_ulsch_cba_rnti(module_idP, cooperation_flag, frameP, subframeP, sched_subframe, nCCE, nCCE_available, first_rb);
#endif


  stop_meas(&eNB->schedule_ulsch);

}



void schedule_ulsch_rnti(module_id_t   module_idP,
                         unsigned char cooperation_flag,
                         frame_t       frameP,
                         sub_frame_t   subframeP,
                         unsigned char sched_subframe,
                         unsigned int *nCCE,
                         unsigned int *nCCE_available,
                         uint16_t     *first_rb)
{

  int                UE_id;
  uint8_t            aggregation    = 2;
  rnti_t             rnti           = -1;
  uint8_t            round          = 0;
  uint8_t            harq_pid       = 0;
  void              *ULSCH_dci      = NULL;
  LTE_eNB_UE_stats  *eNB_UE_stats   = NULL;
  DCI_PDU           *DCI_pdu;
  uint8_t                 status         = 0;
  uint8_t                 rb_table_index = -1;
  uint16_t                TBS = 0;
  int32_t                buffer_occupancy=0;
  uint32_t                cqi_req,cshift,ndi,mcs,rballoc,tpc;
  int32_t                 normalized_rx_power, target_rx_power=-90;
  static int32_t          tpc_accumulated=0;

  int n,CC_id = 0;
  eNB_MAC_INST      *eNB=&eNB_mac_inst[module_idP];
  UE_list_t         *UE_list=&eNB->UE_list;
  UE_TEMPLATE       *UE_template;
  int                rvidx_tab[4] = {0,2,3,1};
  LTE_DL_FRAME_PARMS   *frame_parms;


  //  LOG_I(MAC,"entering ulsch preprocesor\n");

  ulsch_scheduler_pre_processor(module_idP,
                                frameP,
                                subframeP,
                                first_rb,
                                aggregation,
                                nCCE);

  //  LOG_I(MAC,"exiting ulsch preprocesor\n");

  // loop over all active UEs
  for (UE_id=UE_list->head_ul; UE_id>=0; UE_id=UE_list->next_ul[UE_id]) {

    // don't schedule if Msg4 is not received yet
    if (UE_list->UE_template[UE_PCCID(module_idP,UE_id)][UE_id].configured==FALSE) {
      continue;
    }

    rnti = UE_RNTI(module_idP,UE_id);

    if (rnti==NOT_A_RNTI) {
      LOG_W(MAC,"[eNB %d] frame %d subfarme %d, UE %d: no RNTI \n", module_idP,frameP,subframeP,UE_id);
      continue;
    }

    // loop over all active UL CC_ids for this UE
    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];
      frame_parms = mac_xface->get_lte_frame_parms(module_idP,CC_id);
      eNB_UE_stats = mac_xface->get_eNB_UE_stats(module_idP,CC_id,rnti);

      if (eNB_UE_stats==NULL) {
        LOG_W(MAC,"[eNB %d] frame %d subframe %d, UE %d CC %d: no PHY context\n", module_idP,frameP,subframeP,UE_id,CC_id);
        continue; // mac_xface->macphy_exit("[MAC][eNB] Cannot find eNB_UE_stats\n");
      }

      if (nCCE_available[CC_id] < (1<<aggregation)) {
        LOG_W(MAC,"[eNB %d] frame %d subframe %d, UE %d CC %d: not enough nCCE (%d)\n", module_idP,frameP,subframeP,UE_id,CC_id,nCCE_available[CC_id]);
        continue; // break;
      }


      if (eNB_UE_stats->mode == PUSCH) { // ue has a ulsch channel

        DCI_pdu = &eNB->common_channels[CC_id].DCI_pdu;
        UE_template = &UE_list->UE_template[CC_id][UE_id];

        if (mac_xface->get_ue_active_harq_pid(module_idP,CC_id,rnti,frameP,subframeP,&harq_pid,&round,1) == -1 ) {
          LOG_W(MAC,"[eNB %d] Scheduler Frame %d, subframeP %d: candidate harq_pid from PHY for UE %d CC %d RNTI %x\n",
                module_idP,frameP,subframeP, UE_id, CC_id, rnti);
          //  NN --> RK: Don't schedule UE if we cannot get harq pid
          //should we continue or set harq_pid to 0?
          continue;
        } else
          LOG_T(MAC,"[eNB %d] Frame %d, subframeP %d, UE %d CC %d : got harq pid %d  round %d (nCCE %d, rnti %x,mode %s)\n",
                module_idP,frameP,subframeP,UE_id,CC_id, harq_pid, round,nCCE[CC_id],rnti,mode_string[eNB_UE_stats->mode]);

#undef EXMIMO_IOT
#ifndef EXMIMO_IOT

        if (((UE_is_to_be_scheduled(module_idP,CC_id,UE_id)>0)) || (round>0) || ((frameP%10)==0))
          // if there is information on bsr of DCCH, DTCH or if there is UL_SR, or if there is a packet to retransmit, or we want to schedule a periodic feedback every 10 frames
#else
        if (round==0)
#endif
        {
          // reset the scheduling request
          UE_template->ul_SR = 0;
          aggregation = process_ue_cqi(module_idP,UE_id); // =2 by default!!
          status = mac_eNB_get_rrc_status(module_idP,rnti);
          cqi_req = (status < RRC_CONNECTED)? 0:1;

          //power control
          //compute the expected ULSCH RX power (for the stats)

          // this is the normalized RX power and this should be constant (regardless of mcs
          normalized_rx_power = eNB_UE_stats->UL_rssi[0];
          target_rx_power = mac_xface->get_target_pusch_rx_power(module_idP,CC_id);

          // this assumes accumulated tpc
	  // make sure that we are only sending a tpc update once a frame, otherwise the control loop will freak out
	  int32_t framex10psubframe = UE_template->pusch_tpc_tx_frame*10+UE_template->pusch_tpc_tx_subframe;
          if (((framex10psubframe+10)<=(frameP*10+subframeP)) || //normal case
	      ((framex10psubframe>(frameP*10+subframeP)) && (((10240-framex10psubframe+frameP*10+subframeP)>=10)))) //frame wrap-around
	    {
	    UE_template->pusch_tpc_tx_frame=frameP;
	    UE_template->pusch_tpc_tx_subframe=subframeP;
            if (normalized_rx_power>(target_rx_power+1)) {
              tpc = 0; //-1
              tpc_accumulated--;
            } else if (normalized_rx_power<(target_rx_power-1)) {
              tpc = 2; //+1
              tpc_accumulated++;
            } else {
              tpc = 1; //0
            }
          } else {
            tpc = 1; //0
          }

	  if (tpc!=1) {
	    LOG_D(MAC,"[eNB %d] ULSCH scheduler: frame %d, subframe %d, harq_pid %d, tpc %d, accumulated %d, normalized/target rx power %d/%d\n",
		  module_idP,frameP,subframeP,harq_pid,tpc,
		  tpc_accumulated,normalized_rx_power,target_rx_power);
	  }

          // new transmission
          if (round==0) {

            ndi = 1-UE_template->oldNDI_UL[harq_pid];
            UE_template->oldNDI_UL[harq_pid]=ndi;
	    UE_list->eNB_UE_stats[CC_id][UE_id].normalized_rx_power=normalized_rx_power;
	    UE_list->eNB_UE_stats[CC_id][UE_id].target_rx_power=target_rx_power;
	    UE_list->eNB_UE_stats[CC_id][UE_id].ulsch_mcs1=UE_template->pre_assigned_mcs_ul;
            mcs = cmin (UE_template->pre_assigned_mcs_ul, openair_daq_vars.target_ue_ul_mcs); // adjust, based on user-defined MCS

            if (UE_template->pre_allocated_rb_table_index_ul >=0) {
              rb_table_index=UE_template->pre_allocated_rb_table_index_ul;
            } else {
	      mcs=cmin (10, openair_daq_vars.target_ue_ul_mcs);
              rb_table_index=5; // for PHR
	    }

            UE_list->eNB_UE_stats[CC_id][UE_id].ulsch_mcs2=mcs;
            buffer_occupancy = UE_template->ul_total_buffer;

            while ((rb_table[rb_table_index]>(frame_parms->N_RB_UL-1-first_rb[CC_id])) &&
                   (rb_table_index>0)) {
              rb_table_index--;
            }

            TBS = mac_xface->get_TBS_UL(mcs,rb_table[rb_table_index]);
	    UE_list->eNB_UE_stats[CC_id][UE_id].total_rbs_used_rx+=rb_table[rb_table_index];
	    UE_list->eNB_UE_stats[CC_id][UE_id].ulsch_TBS=TBS;
            buffer_occupancy -= TBS;
            rballoc = mac_xface->computeRIV(frame_parms->N_RB_UL,
                                            first_rb[CC_id],
                                            rb_table[rb_table_index]);
            // increment for next UE allocation
            first_rb[CC_id]+=rb_table[rb_table_index];
            //store for possible retransmission
            UE_template->nb_rb_ul[harq_pid] = rb_table[rb_table_index];

            LOG_D(MAC,"[eNB %d][PUSCH %d/%x] CC_id %d Frame %d subframeP %d Scheduled UE %d (mcs %d, first rb %d, nb_rb %d, rb_table_index %d, TBS %d, harq_pid %d)\n",
                  module_idP,harq_pid,rnti,CC_id,frameP,subframeP,UE_id,mcs,
                  first_rb[CC_id],rb_table[rb_table_index],
                  rb_table_index,TBS,harq_pid);
            // Adjust BSR entries for LCGIDs
            adjust_bsr_info(buffer_occupancy,
                            TBS,
                            UE_template);

          } else if (round > 0) { //we schedule a retransmission

            ndi = UE_template->oldNDI_UL[harq_pid];

            if ((round&3)==0) {
              mcs = openair_daq_vars.target_ue_ul_mcs;
            } else {
              mcs = rvidx_tab[round&3] + 28; //not correct for round==4!

            }

            LOG_D(MAC,"[eNB %d][PUSCH %d/%x] CC_id %d Frame %d subframeP %d Scheduled UE retransmission (mcs %d, first rb %d, nb_rb %d, harq_pid %d, round %d)\n",
                  module_idP,UE_id,rnti,CC_id,frameP,subframeP,mcs,
                  first_rb[CC_id],UE_template->nb_rb_ul[harq_pid],
		  harq_pid, round);

            rballoc = mac_xface->computeRIV(frame_parms->N_RB_UL,
                                            first_rb[CC_id],
                                            UE_template->nb_rb_ul[harq_pid]);
            first_rb[CC_id]+=UE_template->nb_rb_ul[harq_pid];  // increment for next UE allocation
         
	    UE_list->eNB_UE_stats[CC_id][UE_id].num_retransmission_rx+=1;
	    UE_list->eNB_UE_stats[CC_id][UE_id].rbs_used_retx_rx=UE_template->nb_rb_ul[harq_pid];
	    UE_list->eNB_UE_stats[CC_id][UE_id].total_rbs_used_rx+=UE_template->nb_rb_ul[harq_pid];
	    UE_list->eNB_UE_stats[CC_id][UE_id].ulsch_mcs1=mcs;
	    UE_list->eNB_UE_stats[CC_id][UE_id].ulsch_mcs2=mcs;
	  }

          // Cyclic shift for DM RS
          if(cooperation_flag == 2) {
            if(UE_id == 1) { // For Distriibuted Alamouti, cyclic shift applied to 2nd UE
              cshift = 1;
            } else {
              cshift = 0;
            }
          } else {
            cshift = 0;// values from 0 to 7 can be used for mapping the cyclic shift (36.211 , Table 5.5.2.1.1-1)
          }

          if (frame_parms->frame_type == TDD) {
            switch (frame_parms->N_RB_UL) {
            case 6:
              ULSCH_dci = UE_template->ULSCH_DCI[harq_pid];

              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->type     = 0;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->hopping  = 0;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->rballoc  = rballoc;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->mcs      = mcs;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->ndi      = ndi;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->TPC      = tpc;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->cshift   = cshift;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->padding  = 0;
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->dai      = UE_template->DAI_ul[sched_subframe];
              ((DCI0_1_5MHz_TDD_1_6_t *)ULSCH_dci)->cqi_req  = cqi_req;

              add_ue_spec_dci(DCI_pdu,
                              ULSCH_dci,
                              rnti,
                              sizeof(DCI0_1_5MHz_TDD_1_6_t),
                              aggregation,
                              sizeof_DCI0_1_5MHz_TDD_1_6_t,
                              format0,
                              0);
              break;

            default:
            case 25:
              ULSCH_dci = UE_template->ULSCH_DCI[harq_pid];

              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->type     = 0;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->hopping  = 0;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->rballoc  = rballoc;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->mcs      = mcs;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->ndi      = ndi;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->TPC      = tpc;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->cshift   = cshift;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->padding  = 0;
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->dai      = UE_template->DAI_ul[sched_subframe];
              ((DCI0_5MHz_TDD_1_6_t *)ULSCH_dci)->cqi_req  = cqi_req;

              add_ue_spec_dci(DCI_pdu,
                              ULSCH_dci,
                              rnti,
                              sizeof(DCI0_5MHz_TDD_1_6_t),
                              aggregation,
                              sizeof_DCI0_5MHz_TDD_1_6_t,
                              format0,
                              0);
              break;

            case 50:
              ULSCH_dci = UE_template->ULSCH_DCI[harq_pid];

              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->type     = 0;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->hopping  = 0;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->rballoc  = rballoc;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->mcs      = mcs;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->ndi      = ndi;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->TPC      = tpc;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->cshift   = cshift;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->padding  = 0;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->dai      = UE_template->DAI_ul[sched_subframe];
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->cqi_req  = cqi_req;

              add_ue_spec_dci(DCI_pdu,
                              ULSCH_dci,
                              rnti,
                              sizeof(DCI0_10MHz_TDD_1_6_t),
                              aggregation,
                              sizeof_DCI0_10MHz_TDD_1_6_t,
                              format0,
                              0);
              break;

            case 100:
              ULSCH_dci = UE_template->ULSCH_DCI[harq_pid];

              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->type     = 0;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->hopping  = 0;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->rballoc  = rballoc;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->mcs      = mcs;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->ndi      = ndi;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->TPC      = tpc;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->cshift   = cshift;
              ((DCI0_10MHz_TDD_1_6_t *)ULSCH_dci)->padding  = 0;
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->dai      = UE_template->DAI_ul[sched_subframe];
              ((DCI0_20MHz_TDD_1_6_t *)ULSCH_dci)->cqi_req  = cqi_req;

              add_ue_spec_dci(DCI_pdu,
                              ULSCH_dci,
                              rnti,
                              sizeof(DCI0_20MHz_TDD_1_6_t),
                              aggregation,
                              sizeof_DCI0_20MHz_TDD_1_6_t,
                              format0,
                              0);
              break;
            }
          } // TDD
          else { //FDD
            switch (frame_parms->N_RB_UL) {
            case 25:
            default:

              ULSCH_dci          = UE_template->ULSCH_DCI[harq_pid];

              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->type     = 0;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->hopping  = 0;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->rballoc  = rballoc;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->mcs      = mcs;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->ndi      = ndi;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->TPC      = tpc;
              ((DCI0_5MHz_FDD_t *)ULSCH_dci)->cshift   = cshift;