eNB_scheduler_mch.c

/*
 * 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 eNB_scheduler_mch.c
 * \brief procedures related to eNB for the MCH transport channel
 * \author  Navid Nikaein and Raymond Knopp
 * \date 2012 - 2014
 * \email: navid.nikaein@eurecom.fr
 * \version 1.0
 * @ingroup _mac

 */


#include "LAYER2/MAC/mac.h"
#include "LAYER2/MAC/mac_proto.h"
#include "LAYER2/MAC/mac_extern.h"
#include "common/utils/LOG/log.h"
#include "common/utils/LOG/vcd_signal_dumper.h"
#include "UTIL/OPT/opt.h"
#include "OCG.h"
#include "OCG_extern.h"
#include "PHY/LTE_TRANSPORT/transport_common_proto.h"

#include "RRC/LTE/rrc_extern.h"
#include "RRC/L2_INTERFACE/openair_rrc_L2_interface.h"

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

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

#include "SIMULATION/TOOLS/sim.h"	// for taus

#define ENABLE_MAC_PAYLOAD_DEBUG
#define DEBUG_eNB_SCHEDULER 1
#include "common/ran_context.h"

extern RAN_CONTEXT_t RC;

#if (LTE_RRC_VERSION >= MAKE_VERSION(10, 0, 0))
int8_t
get_mbsfn_sf_alloction(module_id_t module_idP, uint8_t CC_id,
		       uint8_t mbsfn_sync_area)
{
    // currently there is one-to-one mapping between sf allocation pattern and sync area
    if (mbsfn_sync_area > MAX_MBSFN_AREA) {
	LOG_W(MAC,
	      "[eNB %d] CC_id %d MBSFN synchronization area %d out of range\n ",
	      module_idP, CC_id, mbsfn_sync_area);
	return -1;
    } else if (RC.mac[module_idP]->
	       common_channels[CC_id].mbsfn_SubframeConfig[mbsfn_sync_area]
	       != NULL) {
	return mbsfn_sync_area;
    } else {
	LOG_W(MAC,
	      "[eNB %d] CC_id %d MBSFN Subframe Config pattern %d not found \n ",
	      module_idP, CC_id, mbsfn_sync_area);
	return -1;
    }
}

int
schedule_MBMS(module_id_t module_idP, uint8_t CC_id, frame_t frameP,
	      sub_frame_t subframeP)
{

    int mcch_flag = 0, mtch_flag = 0, msi_flag = 0;
    int mbsfn_period = 0;	// 1<<(RC.mac[module_idP]->mbsfn_SubframeConfig[0]->radioframeAllocationPeriod);
    int mcch_period = 0;	//32<<(RC.mac[module_idP]->mbsfn_AreaInfo[0]->mcch_Config_r9.mcch_RepetitionPeriod_r9);
    int mch_scheduling_period =
	8 << (RC.mac[module_idP]->common_channels[CC_id].
	      pmch_Config[0]->mch_SchedulingPeriod_r9);
    unsigned char mcch_sdu_length;
    unsigned char header_len_mcch = 0, header_len_msi =
	0, header_len_mtch = 0, header_len_mtch_temp =
	0, header_len_mcch_temp = 0, header_len_msi_temp = 0;
    int ii = 0, msi_pos = 0;
    int mcch_mcs = -1;
    uint16_t TBS, j = -1, padding = 0, post_padding = 0;
    mac_rlc_status_resp_t rlc_status;
    int num_mtch;
    int msi_length, i, k;
    unsigned char sdu_lcids[11], num_sdus = 0, offset = 0;
    uint16_t sdu_lengths[11], sdu_length_total = 0;
    unsigned char mch_buffer[MAX_DLSCH_PAYLOAD_BYTES];	// check the max value, this is for dlsch only

    COMMON_channels_t *cc = &RC.mac[module_idP]->common_channels[CC_id];

    cc->MCH_pdu.Pdu_size = 0;

    for (i = 0; i < cc->num_active_mbsfn_area; i++) {
	// assume, that there is always a mapping
	if ((j = get_mbsfn_sf_alloction(module_idP, CC_id, i)) == -1) {
	    return 0;
	}

	mbsfn_period =
	    1 << (cc->mbsfn_SubframeConfig[j]->radioframeAllocationPeriod);
	mcch_period =
	    32 << (cc->mbsfn_AreaInfo[i]->
		   mcch_Config_r9.mcch_RepetitionPeriod_r9);
	msi_pos = 0;
	ii = 0;
	LOG_D(MAC,
	      "[eNB %d] CC_id %d Frame %d subframeP %d : Checking MBSFN Sync Area %d/%d with SF allocation %d/%d for MCCH and MTCH (mbsfn period %d, mcch period %d)\n",
	      module_idP, CC_id, frameP, subframeP, i,
	      cc->num_active_mbsfn_area, j, cc->num_sf_allocation_pattern,
	      mbsfn_period, mcch_period);


	switch (cc->mbsfn_AreaInfo[i]->mcch_Config_r9.signallingMCS_r9) {
	case 0:
	    mcch_mcs = 2;
	    break;

	case 1:
	    mcch_mcs = 7;
	    break;

	case 2:
	    mcch_mcs = 13;
	    break;

	case 3:
	    mcch_mcs = 19;
	    break;
	}

	// 1st: Check the MBSFN subframes from SIB2 info (SF allocation pattern i, max 8 non-overlapping patterns exist)
	if (frameP % mbsfn_period == cc->mbsfn_SubframeConfig[j]->radioframeAllocationOffset) {	// MBSFN frameP
	    if (cc->mbsfn_SubframeConfig[j]->subframeAllocation.present == LTE_MBSFN_SubframeConfig__subframeAllocation_PR_oneFrame) {	// one-frameP format

		//  Find the first subframeP in this MCH to transmit MSI
		if (frameP % mch_scheduling_period ==
		    cc->mbsfn_SubframeConfig[j]->
		    radioframeAllocationOffset) {
		    while (ii == 0) {
			ii = cc->
			    mbsfn_SubframeConfig[j]->subframeAllocation.
			    choice.oneFrame.buf[0] & (0x80 >> msi_pos);
			msi_pos++;
		    }

		    LOG_D(MAC,
			  "[eNB %d] CC_id %d Frame %d subframeP %d : sync area %d sf allocation pattern %d sf alloc %x msi pos is %d \n",
			  module_idP, CC_id, frameP, subframeP, i, j,
			  cc->mbsfn_SubframeConfig[j]->
			  subframeAllocation.choice.oneFrame.buf[0],
			  msi_pos);
		}
		// Check if the subframeP is for MSI, MCCH or MTCHs and Set the correspoding flag to 1
		switch (subframeP) {
		case 1:
		    if (cc->tdd_Config == NULL) {
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF1) ==
			    MBSFN_FDD_SF1) {
			    if (msi_pos == 1) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF1) ==
				 MBSFN_FDD_SF1)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 2:
		    if (cc->tdd_Config == NULL) {
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF2) ==
			    MBSFN_FDD_SF2) {
			    if (msi_pos == 2) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF2) ==
				 MBSFN_FDD_SF2)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 3:
		    if (cc->tdd_Config != NULL) {	// TDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_TDD_SF3) ==
			    MBSFN_TDD_SF3) {
			    if (msi_pos == 1) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_TDD_SF3) ==
				 MBSFN_TDD_SF3)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    } else {	// FDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF3) ==
			    MBSFN_FDD_SF3) {
			    if (msi_pos == 3) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF3) ==
				 MBSFN_FDD_SF3)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 4:
		    if (cc->tdd_Config != NULL) {
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_TDD_SF4) ==
			    MBSFN_TDD_SF4) {
			    if (msi_pos == 2) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_TDD_SF4) ==
				 MBSFN_TDD_SF4)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 6:
		    if (cc->tdd_Config == NULL) {
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF6) ==
			    MBSFN_FDD_SF6) {
			    if (msi_pos == 4) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF6) ==
				 MBSFN_FDD_SF6)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 7:
		    if (cc->tdd_Config != NULL) {	// TDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_TDD_SF7) ==
			    MBSFN_TDD_SF7) {
			    if (msi_pos == 3) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_TDD_SF7) ==
				 MBSFN_TDD_SF7)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    } else {	// FDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF7) ==
			    MBSFN_FDD_SF7) {
			    if (msi_pos == 5) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF7) ==
				 MBSFN_FDD_SF7)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 8:
		    if (cc->tdd_Config != NULL) {	//TDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_TDD_SF8) ==
			    MBSFN_TDD_SF8) {
			    if (msi_pos == 4) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_TDD_SF8) ==
				 MBSFN_TDD_SF8)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    } else {	// FDD
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_FDD_SF8) ==
			    MBSFN_FDD_SF8) {
			    if (msi_pos == 6) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_FDD_SF8) ==
				 MBSFN_FDD_SF8)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;

		case 9:
		    if (cc->tdd_Config != NULL) {
			if ((cc->
			     mbsfn_SubframeConfig[j]->subframeAllocation.
			     choice.oneFrame.buf[0] & MBSFN_TDD_SF9) ==
			    MBSFN_TDD_SF9) {
			    if (msi_pos == 5) {
				msi_flag = 1;
			    }

			    if ((frameP % mcch_period ==
				 cc->mbsfn_AreaInfo[i]->
				 mcch_Config_r9.mcch_Offset_r9)
				&&
				((cc->mbsfn_AreaInfo[i]->
				  mcch_Config_r9.sf_AllocInfo_r9.
				  buf[0] & MBSFN_TDD_SF9) ==
				 MBSFN_TDD_SF9)) {
				mcch_flag = 1;
			    }

			    mtch_flag = 1;
			}
		    }

		    break;
		}		// end switch

		// sf allocation is non-overlapping
		if ((msi_flag == 1) || (mcch_flag == 1)
		    || (mtch_flag == 1)) {
		    LOG_D(MAC,
			  "[eNB %d] CC_id %d Frame %d Subframe %d: sync area %d SF alloc %d: msi flag %d, mcch flag %d, mtch flag %d\n",
			  module_idP, CC_id, frameP, subframeP, i, j,
			  msi_flag, mcch_flag, mtch_flag);
		    break;
		}
	    } else {		// four-frameP format
	    }
	}
    }				// end of for loop

    cc->msi_active = 0;
    cc->mcch_active = 0;
    cc->mtch_active = 0;

    // Calculate the mcs
    if ((msi_flag == 1) || (mcch_flag == 1)) {
	cc->MCH_pdu.mcs = mcch_mcs;
    } else if (mtch_flag == 1) {	// only MTCH in this subframeP
	cc->MCH_pdu.mcs = cc->pmch_Config[0]->dataMCS_r9;
    }
    // 2nd: Create MSI, get MCCH from RRC and MTCHs from RLC

    // there is MSI (MCH Scheduling Info)
    if (msi_flag == 1) {
	// Create MSI here
	uint16_t msi_control_element[29], *msi_ptr;

	msi_ptr = &msi_control_element[0];
	((MSI_ELEMENT *) msi_ptr)->lcid = MCCH_LCHANID;	//MCCH

	if (mcch_flag == 1) {
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_MSB = 0;
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_LSB = 0;
	} else {		// no mcch for this MSP
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_MSB = 0x7;	// stop value is 2047
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_LSB = 0xff;
	}

	msi_ptr += sizeof(MSI_ELEMENT);

	//Header for MTCHs
	num_mtch = cc->mbms_SessionList[0]->list.count;

	for (k = 0; k < num_mtch; k++) {	// loop for all session in this MCH (MCH[0]) at this moment
	    ((MSI_ELEMENT *) msi_ptr)->lcid = cc->mbms_SessionList[0]->list.array[k]->logicalChannelIdentity_r9;	//mtch_lcid;
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_MSB = 0;	// last subframeP of this mtch (only one mtch now)
	    ((MSI_ELEMENT *) msi_ptr)->stop_sf_LSB = 0xB;
	    msi_ptr += sizeof(MSI_ELEMENT);
	}

	msi_length = msi_ptr - msi_control_element;

	if (msi_length < 128) {
	    header_len_msi = 2;
	} else {
	    header_len_msi = 3;
	}

	LOG_D(MAC,
	      "[eNB %d] CC_id %d Frame %d : MSI->MCH, length of MSI is %d bytes \n",
	      module_idP, CC_id, frameP, msi_length);
	//LOG_D(MAC,"Scheduler: MSI is transmitted in this subframeP \n" );

	//   LOG_D(MAC,"Scheduler: MSI length is %d bytes\n",msi_length);
	// Store MSI data to mch_buffer[0]
	memcpy((char *) &mch_buffer[sdu_length_total],
	       msi_control_element, msi_length);

	sdu_lcids[num_sdus] = MCH_SCHDL_INFO;
	sdu_lengths[num_sdus] = msi_length;
	sdu_length_total += sdu_lengths[num_sdus];
	LOG_I(MAC, "[eNB %d] CC_id %d Create %d bytes for MSI\n",
	      module_idP, CC_id, sdu_lengths[num_sdus]);
	num_sdus++;
	cc->msi_active = 1;
    }
    // there is MCCH
    if (mcch_flag == 1) {
	LOG_D(MAC,
	      "[eNB %d] CC_id %d Frame %d Subframe %d: Schedule MCCH MESSAGE (area %d, sfAlloc %d)\n",
	      module_idP, CC_id, frameP, subframeP, i, j);

	mcch_sdu_length = mac_rrc_data_req(module_idP, CC_id, frameP, MCCH, 1, &cc->MCCH_pdu.payload[0], 
					   i);	// this is the mbsfn sync area index

	if (mcch_sdu_length > 0) {
	    LOG_D(MAC,
		  "[eNB %d] CC_id %d Frame %d subframeP %d : MCCH->MCH, Received %d bytes from RRC \n",
		  module_idP, CC_id, frameP, subframeP, mcch_sdu_length);

	    header_len_mcch = 2;

	    if (cc->tdd_Config != NULL) {
		LOG_D(MAC,
		      "[eNB %d] CC_id %d Frame %d subframeP %d: Scheduling MCCH->MCH (TDD) for MCCH message %d bytes (mcs %d )\n",
		      module_idP, CC_id, frameP, subframeP,
		      mcch_sdu_length, mcch_mcs);
	    } else {
		LOG_I(MAC,
		      "[eNB %d] CC_id %d Frame %d subframeP %d: Scheduling MCCH->MCH (FDD) for MCCH message %d bytes (mcs %d)\n",
		      module_idP, CC_id, frameP, subframeP,
		      mcch_sdu_length, mcch_mcs);
	    }

	    cc->mcch_active = 1;

	    memcpy((char *) &mch_buffer[sdu_length_total],
		   &cc->MCCH_pdu.payload[0], mcch_sdu_length);
	    sdu_lcids[num_sdus] = MCCH_LCHANID;
	    sdu_lengths[num_sdus] = mcch_sdu_length;

	    if (sdu_lengths[num_sdus] > 128) {
		header_len_mcch = 3;
	    }

	    sdu_length_total += sdu_lengths[num_sdus];
	    LOG_D(MAC,
		  "[eNB %d] CC_id %d Got %d bytes for MCCH from RRC \n",
		  module_idP, CC_id, sdu_lengths[num_sdus]);
	    num_sdus++;
	}
    }

    TBS =
	get_TBS_DL(cc->MCH_pdu.mcs, to_prb(cc->mib->message.dl_Bandwidth));
#if (LTE_RRC_VERSION >= MAKE_VERSION(10, 0, 0))
    // do not let mcch and mtch multiplexing when relaying is active
    // for sync area 1, so not transmit data
    //if ((i == 0) && ((RC.mac[module_idP]->MBMS_flag != multicast_relay) || (RC.mac[module_idP]->mcch_active==0))) {
#endif

    // there is MTCHs, loop if there are more than 1
    if (mtch_flag == 1) {
	// Calculate TBS
	/* if ((msi_flag==1) || (mcch_flag==1)) {
	   TBS = mac_xface->get_TBS(mcch_mcs, mac_xface->frame_parms->N_RB_DL);
	   }
	   else { // only MTCH in this subframeP
	   TBS = mac_xface->get_TBS(RC.mac[module_idP]->pmch_Config[0]->dataMCS_r9, mac_xface->frame_parms->N_RB_DL);
	   }

	   // get MTCH data from RLC (like for DTCH)
	   LOG_D(MAC,"[eNB %d] CC_id %d Frame %d subframe %d: Schedule MTCH (area %d, sfAlloc %d)\n",Mod_id,CC_id,frame,subframe,i,j);

	   header_len_mtch = 3;
	   LOG_D(MAC,"[eNB %d], CC_id %d, Frame %d, MTCH->MCH, Checking RLC status (rab %d, tbs %d, len %d)\n",
	   Mod_id,CC_id,frame,MTCH,TBS,
	   TBS-header_len_mcch-header_len_msi-sdu_length_total-header_len_mtch);

	   rlc_status = mac_rlc_status_ind(Mod_id,frame,1,RLC_MBMS_YES,MTCH+ (maxDRB + 3) * MAX_MOBILES_PER_RG,
	   TBS-header_len_mcch-header_len_msi-sdu_length_total-header_len_mtch);
	   printf("frame %d, subframe %d,  rlc_status.bytes_in_buffer is %d\n",frame,subframe, rlc_status.bytes_in_buffer);

	 */

	// get MTCH data from RLC (like for DTCH)
	LOG_D(MAC,
	      "[eNB %d] CC_id %d Frame %d subframeP %d: Schedule MTCH (area %d, sfAlloc %d)\n",
	      module_idP, CC_id, frameP, subframeP, i, j);

	header_len_mtch = 3;
	LOG_D(MAC,
	      "[eNB %d], CC_id %d, Frame %d, MTCH->MCH, Checking RLC status (rab %d, tbs %d, len %d)\n",
	      module_idP, CC_id, frameP, MTCH, TBS,
	      TBS - header_len_mcch - header_len_msi - sdu_length_total -
	      header_len_mtch);

	rlc_status =
	    mac_rlc_status_ind(module_idP, 0, frameP, subframeP,
			       module_idP, ENB_FLAG_YES, MBMS_FLAG_YES,
			       MTCH,
			       TBS - header_len_mcch - header_len_msi -
			       sdu_length_total - header_len_mtch
#if (LTE_RRC_VERSION >= MAKE_VERSION(14, 0, 0))
                                    ,0, 0
#endif
                                    );

	LOG_D(MAC,
	      "e-MBMS log channel %u frameP %d, subframeP %d,  rlc_status.bytes_in_buffer is %d\n",
	      MTCH, frameP, subframeP, rlc_status.bytes_in_buffer);

	if (rlc_status.bytes_in_buffer > 0) {
	    LOG_I(MAC,
		  "[eNB %d][MBMS USER-PLANE], CC_id %d, Frame %d, MTCH->MCH, Requesting %d bytes from RLC (header len mtch %d)\n",
		  module_idP, CC_id, frameP,
		  TBS - header_len_mcch - header_len_msi -
		  sdu_length_total - header_len_mtch, header_len_mtch);

	    sdu_lengths[num_sdus] = mac_rlc_data_req(module_idP, 0, module_idP, frameP, ENB_FLAG_YES, MBMS_FLAG_YES, MTCH, 0,	//not used
						     (char *)
						     &mch_buffer[sdu_length_total]
#if (LTE_RRC_VERSION >= MAKE_VERSION(14, 0, 0))
                                ,0,
                                 0
#endif
                                 );


	    //sdu_lengths[num_sdus] = mac_rlc_data_req(module_idP,frameP, MBMS_FLAG_NO,  MTCH+(MAX_NUM_RB*(MAX_MOBILES_PER_ENB+1)), (char*)&mch_buffer[sdu_length_total]);
	    LOG_I(MAC,
		  "[eNB %d][MBMS USER-PLANE] CC_id %d Got %d bytes for MTCH %d\n",
		  module_idP, CC_id, sdu_lengths[num_sdus], MTCH);
	    cc->mtch_active = 1;
	    sdu_lcids[num_sdus] = MTCH;
	    sdu_length_total += sdu_lengths[num_sdus];

	    if (sdu_lengths[num_sdus] < 128) {
		header_len_mtch = 2;
	    }

	    num_sdus++;
	} else {
	    header_len_mtch = 0;
	}
    }
#if (LTE_RRC_VERSION >= MAKE_VERSION(10, 0, 0))
    //  }
#endif

    // FINAL STEP: Prepare and multiplexe MSI, MCCH and MTCHs
    if ((sdu_length_total + header_len_msi + header_len_mcch +
	 header_len_mtch) > 0) {
	// Adjust the last subheader
	/*                                 if ((msi_flag==1) || (mcch_flag==1)) {
	   RC.mac[module_idP]->MCH_pdu.mcs = mcch_mcs;
	   }
	   else if (mtch_flag == 1) { // only MTCH in this subframeP
	   RC.mac[module_idP]->MCH_pdu.mcs = RC.mac[module_idP]->pmch_Config[0]->dataMCS_r9;
	   }
	 */
	header_len_mtch_temp = header_len_mtch;
	header_len_mcch_temp = header_len_mcch;
	header_len_msi_temp = header_len_msi;

	if (header_len_mtch > 0) {
	    header_len_mtch = 1;	// remove Length field in the  subheader for the last PDU
	} else if (header_len_mcch > 0) {
	    header_len_mcch = 1;
	} else {
	    header_len_msi = 1;
	}

	// Calculate the padding
	if ((TBS - header_len_mtch - header_len_mcch - header_len_msi -
	     sdu_length_total) < 0) {
	    LOG_E(MAC, "Error in building MAC PDU, TBS %d < PDU %d \n",
		  TBS,
		  header_len_mtch + header_len_mcch + header_len_msi +
		  sdu_length_total);
	    return 0;
	} else
	    if ((TBS - header_len_mtch - header_len_mcch - header_len_msi -
		 sdu_length_total) <= 2) {
	    padding =
		(TBS - header_len_mtch - header_len_mcch - header_len_msi -
		 sdu_length_total);
	    post_padding = 0;
	} else {		// using post_padding, give back the Length field of subheader  for the last PDU
	    padding = 0;

	    if (header_len_mtch > 0) {
		header_len_mtch = header_len_mtch_temp;
	    } else if (header_len_mcch > 0) {
		header_len_mcch = header_len_mcch_temp;
	    } else {
		header_len_msi = header_len_msi_temp;
	    }

	    post_padding =
		TBS - sdu_length_total - header_len_msi - header_len_mcch -
		header_len_mtch;
	}

	// Generate the MAC Header for MCH
	// here we use the function for DLSCH because DLSCH & MCH have the same Header structure
	offset = generate_dlsch_header((unsigned char *) cc->MCH_pdu.payload, num_sdus, sdu_lengths, sdu_lcids, 255,	// no drx
				       31,	// no timing advance
				       NULL,	// no contention res id
				       padding, post_padding);

	cc->MCH_pdu.Pdu_size = TBS;
	cc->MCH_pdu.sync_area = i;
	cc->MCH_pdu.msi_active = cc->msi_active;
	cc->MCH_pdu.mcch_active = cc->mcch_active;
	cc->MCH_pdu.mtch_active = cc->mtch_active;
	LOG_D(MAC,
	      " MCS for this sf is %d (mcch active %d, mtch active %d)\n",
	      cc->MCH_pdu.mcs, cc->MCH_pdu.mcch_active,
	      cc->MCH_pdu.mtch_active);
	LOG_I(MAC,
	      "[eNB %d][MBMS USER-PLANE ] CC_id %d Generate header : sdu_length_total %d, num_sdus %d, sdu_lengths[0] %d, sdu_lcids[0] %d => payload offset %d,padding %d,post_padding %d (mcs %d, TBS %d), header MTCH %d, header MCCH %d, header MSI %d\n",
	      module_idP, CC_id, sdu_length_total, num_sdus,
	      sdu_lengths[0], sdu_lcids[0], offset, padding, post_padding,
	      cc->MCH_pdu.mcs, TBS, header_len_mtch, header_len_mcch,
	      header_len_msi);
	// copy SDU to mch_pdu after the MAC Header
	memcpy(&cc->MCH_pdu.payload[offset], mch_buffer, sdu_length_total);

	// filling remainder of MCH with random data if necessery
	for (j = 0; j < (TBS - sdu_length_total - offset); j++) {
	    cc->MCH_pdu.payload[offset + sdu_length_total + j] =
		(char) (taus() & 0xff);
	}

	/* Tracing of PDU is done on UE side */
	if (opt_enabled == 1) {
	    trace_pdu(DIRECTION_DOWNLINK, (uint8_t *) cc->MCH_pdu.payload, TBS, module_idP, WS_M_RNTI , 0xffff,	// M_RNTI = 6 in wirehsark
		      RC.mac[module_idP]->frame,
		      RC.mac[module_idP]->subframe, 0, 0);
	    LOG_D(OPT,
		  "[eNB %d][MCH] CC_id %d Frame %d : MAC PDU with size %d\n",
		  module_idP, CC_id, frameP, TBS);
	}

	/*
	   for (j=0;j<sdu_length_total;j++)
	   printf("%2x.",RC.mac[module_idP]->MCH_pdu.payload[j+offset]);
	   printf(" \n"); */
	return 1;
    } else {
	cc->MCH_pdu.Pdu_size = 0;
	cc->MCH_pdu.sync_area = 0;
	cc->MCH_pdu.msi_active = 0;
	cc->MCH_pdu.mcch_active = 0;
	cc->MCH_pdu.mtch_active = 0;
	// for testing purpose, fill with random data
	//for (j=0;j<(TBS-sdu_length_total-offset);j++)
	//  RC.mac[module_idP]->MCH_pdu.payload[offset+sdu_length_total+j] = (char)(taus()&0xff);
	return 0;
    }

    //this is for testing
    /*
       if (mtch_flag == 1) {
       //  LOG_D(MAC,"DUY: mch_buffer length so far is : %ld\n", &mch_buffer[sdu_length_total]-&mch_buffer[0]);
       return 1;
       }
       else
       return 0;
     */
}

MCH_PDU *get_mch_sdu(module_id_t module_idP, int CC_id, frame_t frameP,
		     sub_frame_t subframeP)
{
    //  RC.mac[module_idP]->MCH_pdu.mcs=0;
    //LOG_D(MAC," MCH_pdu.mcs is %d\n", RC.mac[module_idP]->MCH_pdu.mcs);
//#warning "MCH pdu should take the CC_id index"
    return (&RC.mac[module_idP]->common_channels[CC_id].MCH_pdu);
}

#endif