diff --git a/openair1/PHY/LTE_TRANSPORT/if4_tools.c b/openair1/PHY/LTE_TRANSPORT/if4_tools.c
new file mode 100644
index 0000000000000000000000000000000000000000..669b7a6739ab9d6ef2e8abb361bbe55806af0869
--- /dev/null
+++ b/openair1/PHY/LTE_TRANSPORT/if4_tools.c
@@ -0,0 +1,186 @@
+/*******************************************************************************
+ OpenAirInterface
+ Copyright(c) 1999 - 2014 Eurecom
+
+ OpenAirInterface is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+
+ OpenAirInterface is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with OpenAirInterface.The full GNU General Public License is
+ included in this distribution in the file called "COPYING". If not,
+ see <http://www.gnu.org/licenses/>.
+
+ Contact Information
+ OpenAirInterface Admin: openair_admin@eurecom.fr
+ OpenAirInterface Tech : openair_tech@eurecom.fr
+ OpenAirInterface Dev : openair4g-devel@lists.eurecom.fr
+
+ Address : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE
+
+ *******************************************************************************/
+
+/*! \file PHY/LTE_TRANSPORT/if4_tools.c
+* \brief
+* \author Mauricio Gunther, S. Sandeep Kumar, Raymond Knopp
+* \date 2016
+* \version 0.1
+* \company Eurecom
+* \email: knopp@eurecom.fr
+* \note
+* \warning
+*/
+
+#include "PHY/LTE_TRANSPORT/if4_tools.h"
+
+// Define how data blocks are stored and transferred
+
+
+void send_IF4(PHY_VARS_eNB *eNB, int subframe){
+ eNB_proc_t *proc = &eNB->proc;
+ //int frame=proc->frame_tx;
+ //int subframe=proc->subframe_tx;
+
+ LTE_DL_FRAME_PARMS *fp=&eNB->frame_parms;
+
+ uint32_t i,j;
+ float *data_block = malloc(length*sizeof(long));
+
+ // Generate IF4 packet (for now DL) with frame status information
+ dl_packet = gen_IF4_dl_packet( /* ADD INFO and data_block pointer */ );
+
+ for(i=0; i<fp->symbols_per_tti; i++) {
+
+ // Do compression of the two parts and generate data blocks
+
+ symbol = eNB->common_vars.txdataF[0][0 /*antenna number*/][subframe*fp->ofdm_symbol_size*(fp->symbols_per_tti)]
+ data_block[j] = Atan(symbol[fp->ofmd_symbol_size - NrOfNonZeroValues + j -1])<<16 + Atan(symbol[fp->ofmd_symbol_size - NrOfNonZeroValues + j]);
+ data_block[j+NrOfNonZeroValues] = Atan(subframe[i][j+1])<<16 + Atan(subframe[i][j+2]);
+
+ // Set data blocks and update subframe no./other information to generated packet
+
+
+ // Write the packet(s) to the fronthaul
+
+ }
+
+}
+
+void recv_IF4( /* ADD INFO and data_block pointer */ ) {
+
+ // Read packet(s) from the fronthaul
+
+ // Apply reverse processing - decompression
+
+ // Generate and return the OFDM symbols (txdataF)
+
+}
+
+IF4_dl_packet gen_IF4_dl_packet( /* ADD INFO and data_block pointer */ ) {
+ IF4_dl_packet dl_packet;
+
+ // Set destination and source address
+
+ // Set Type and Sub-Type
+ dl_packet.type = ; //08_0A ?
+ dl_packet.sub_type = 0x0020;
+
+ // Leave reserved as it is
+ //dl_packet.rsvd = ;
+
+ // Set frame status
+ dl_packet.frame_status.ant_num = ;
+ dl_packet.frame_status.ant_start = ;
+ dl_packet.frame_status.rf_num = ;
+ dl_packet.frame_status.sf_num = ;
+ dl_packet.frame_status.sym_num = ;
+ //dl_packet.frame_status.rsvd = ;
+
+ // Set data blocks if sent
+ if (data_block != NULL) {
+
+ } else {
+
+ }
+
+ // Set frame check sequence
+ dl_packet.fcs = ;
+
+ return dl_packet;
+}
+
+IF4_ul_packet gen_IF4_ul_packet( /* ADD INFO and data_block pointer */ ) {
+ IF4_ul_packet ul_packet;
+
+ // Set destination and source address
+
+ // Set Type and Sub-Type
+ ul_packet.type = ; //08_0A ?
+ ul_packet.sub_type = 0x0019;
+
+ // Leave reserved as it is
+ //ul_packet.rsvd = ;
+
+ // Set frame status
+ ul_packet.frame_status.ant_num = ;
+ ul_packet.frame_status.ant_start = ;
+ ul_packet.frame_status.rf_num = ;
+ ul_packet.frame_status.sf_num = ;
+ ul_packet.frame_status.sym_num = ;
+ //ul_packet.frame_status.rsvd = ;
+
+ // Set antenna specific gain
+ ul_packet.gain0.exponent = ;
+ //ul_packet.gain0.rsvd = ;
+
+ // Set data blocks if sent
+ if (data_block != NULL) {
+
+ } else {
+
+ }
+
+ // Set frame check sequence
+ ul_packet.fcs = ;
+
+ return ul_packet;
+}
+
+IF4_prach_packet gen_IF4_prach_packet( /* ADD INFO and data_block pointer */ ) {
+ IF4_prach_packet prach_packet;
+
+ // Set destination and source address
+
+ // Set Type and Sub-Type
+ prach_packet.type = ; //08_0A ?
+ prach_packet.sub_type = 0x0021;
+
+ // Leave reserved as it is
+ //prach_packet.rsvd = ;
+
+ // Set LTE Prach configuration
+ //prach_packet.prach_conf.rsvd = ;
+ prach_packet.prach_conf.ant = ;
+ prach_packet.prach_conf.rf_num = ;
+ prach_packet.prach_conf.sf_num = ;
+ prach_packet.prach_conf.exponent = ;
+
+ // Set data blocks if sent
+ if (data_block != NULL) {
+
+ } else {
+
+ }
+
+ // Set frame check sequence
+ prach_packet.fcs = ;
+
+ return prach_packet;
+}
diff --git a/openair1/PHY/LTE_TRANSPORT/if4_tools.h b/openair1/PHY/LTE_TRANSPORT/if4_tools.h
new file mode 100644
index 0000000000000000000000000000000000000000..3b25e82c6ac6cc627057dd4a763d916df1f6fd40
--- /dev/null
+++ b/openair1/PHY/LTE_TRANSPORT/if4_tools.h
@@ -0,0 +1,164 @@
+/*******************************************************************************
+ OpenAirInterface
+ Copyright(c) 1999 - 2014 Eurecom
+
+ OpenAirInterface is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+
+ OpenAirInterface is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with OpenAirInterface.The full GNU General Public License is
+ included in this distribution in the file called "COPYING". If not,
+ see <http://www.gnu.org/licenses/>.
+
+ Contact Information
+ OpenAirInterface Admin: openair_admin@eurecom.fr
+ OpenAirInterface Tech : openair_tech@eurecom.fr
+ OpenAirInterface Dev : openair4g-devel@lists.eurecom.fr
+
+ Address : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE
+
+ *******************************************************************************/
+
+/*! \file PHY/LTE_TRANSPORT/if4_tools.h
+* \brief
+* \author S. Sandeep Kumar, Raymond Knopp
+* \date 2016
+* \version 0.1
+* \company Eurecom
+* \email: ee13b1025@iith.ac.in, knopp@eurecom.fr
+* \note
+* \warning
+*/
+
+#include <stdint.h>
+
+/// IF4 Frame Status (32 bits)
+struct IF4_frame_status {
+ /// Antenna Numbers
+ uint32_t ant_num:3;
+ /// Antenna Start
+ uint32_t ant_start:3;
+ /// Radio Frame Number
+ uint32_t rf_num:16;
+ /// Sub-frame Number
+ uint32_t sf_num:4;
+ /// Symbol Number
+ uint32_t sym_num:4;
+ /// Reserved
+ uint32_t rsvd:2;
+};
+
+/// IF4 Antenna Gain (16 bits)
+struct IF4_gain {
+ /// Reserved
+ uint32_t rsvd:10;
+ /// FFT Exponent Output
+ uint32_t exponent:6;
+};
+
+/// IF4 LTE PRACH Configuration (32 bits)
+struct IF4_lte_prach_conf {
+ /// Reserved
+ uint32_t rsvd:3;
+ /// Antenna Indication
+ uint32_t ant:3;
+ /// Radio Frame Number
+ uint32_t rf_num:16;
+ /// Sub-frame Number
+ uint32_t sf_num:4;
+ /// FFT Exponent Output
+ uint32_t exponent:6;
+};
+
+struct IF4_dl_packet {
+ /// Destination Address
+
+ /// Source Address
+
+ /// Type
+ uint16_t type;
+ /// Sub-Type
+ uint16_t sub_type;
+ /// Reserved
+ uint32_t rsvd;
+ /// Frame Status
+ IF4_frame_status frame_status;
+ /// Data Blocks
+
+ /// Frame Check Sequence
+ uint32_t fcs;
+};
+
+struct IF4_ul_packet {
+ /// Destination Address
+
+ /// Source Address
+
+ /// Type
+ uint16_t type;
+ /// Sub-Type
+ uint16_t sub_type;
+ /// Reserved
+ uint32_t rsvd;
+ /// Frame Status
+ IF4_frame_status frame_status;
+ /// Gain 0
+ IF4_gain gain0;
+ /// Gain 1
+ IF4_gain gain1;
+ /// Gain 2
+ IF4_gain gain2;
+ /// Gain 3
+ IF4_gain gain3;
+ /// Gain 4
+ IF4_gain gain4;
+ /// Gain 5
+ IF4_gain gain5;
+ /// Gain 6
+ IF4_gain gain6;
+ /// Gain 7
+ IF4_gain gain7;
+ /// Data Blocks
+
+ /// Frame Check Sequence
+ uint32_t fcs;
+};
+
+struct IF4_prach_packet {
+ /// Destination Address
+
+ /// Source Address
+
+ /// Type
+ uint16_t type;
+ /// Sub-Type
+ uint16_t sub_type;
+ /// Reserved
+ uint32_t rsvd;
+ /// LTE Prach Configuration
+ IF4_lte_prach_conf prach_conf;
+ /// Prach Data Block (one antenna)
+
+ /// Frame Check Sequence
+ uint32_t fcs;
+};
+
+// Needs to be checked
+
+IF4_dl_packet gen_IF4_dl_packet();
+
+IF4_ul_packet gen_IF4_ul_packet();
+
+IF4_prach_packet gen_IF4_prach_packet();
+
+void send_IF4(PHY_VARS_eNB *eNB, int subframe);
+
+void recv_IF4(PHY_VARS_eNB *eNB, int subframe);
diff --git a/openair1/SCHED/phy_procedures_lte_eNb.c b/openair1/SCHED/phy_procedures_lte_eNb.c
index 9d43f21106ee4f7a1062ec82bf68cbf58d98b09e..c6245e65e037abc3684f480f8bae0a5e7b223689 100755
--- a/openair1/SCHED/phy_procedures_lte_eNb.c
+++ b/openair1/SCHED/phy_procedures_lte_eNb.c
@@ -2562,6 +2562,9 @@ void phy_procedures_eNB_common_RX(PHY_VARS_eNB *eNB,const uint8_t abstraction_fl
//recv_IF4(eNB,subframe<<1);
//recv_IF4(eNB,1+(subframe<<1));
+ // Tobi aka mr monaco: ETH
+
+
}
else { // should not get here
AssertFatal(1==0, "Unknown eNB->node_function %d",eNB->node_function);