Scenario 1 : Off-network UE2UE link
SynchREF UE (UE1)

UE1(eth0 - 10.10.10.1)--------UE2(eth0 - 10.10.10.2)

Here's an example of /etc/network/interfaces configuration for UE1
auto eth0
   iface eth0 inet static
   address 10.10.10.1
   netmask 255.255.255.0
   gateway 10.10.10.1

Prepare the environment:
 - git clone https://gitlab.eurecom.fr/matzakos/LTE-D2D.git
This branch contains all the current development for DDPS
 - UE MAC<-> UE MAC for Scenario 1
 - eNB MAC<->UE MAC (NFAPI Transport)
 - RRC Extensions for “on-network” cases
 
NFAPI configuration (required even for Scenario 1 target)
 - git clone https://github.com/cisco/open-nFAPI.git
 - cd open-nfapi
 - patch -p1 --dry-run < $OPENAIR_HOME/open-nfapi.oai.patch
Validate that there are no errors
 - patch -p1 < $OPENAIR_HOME/open-nfapi.oai.patch
 
OAI build/execute
 - export NFAPI_DIR=XXX (place where NFAPI was installed)
 - cd cmake_targets
 - ./build_oai --UE
 - cd lte_build_oai/build/
 - cp ../../../targets/bin/.ue* .
 - cp ../../../targets/bin/.usim* .
 - sudo insmod ../../../targets/bin/ue_ip.ko
 UE1: 
 - sudo ifconfig oip0 10.0.0.1
 - sudo iptables -A POSTROUTING  -t mangle -o oip0 -d 224.0.0.1 -j MARK --set-mark 3
 - (if necessary) sudo route add default gw 10.10.10.1 eth0
UE2:
 - sudo ifconfig oip1 10.0.0.2
 - sudo iptables -A POSTROUTING  -t mangle -o oip1 -d 224.0.0.1 -j MARK --set-mark 3
 - (if necessary) sudo route add default gw 10.10.10.1 eth0
Run UE1, then UE2
- sudo ./lte-softmodem-stub -U --emul_iface eth0

Test with Ping
- Sender - UE1: ping -I oip0 224.0.0.1
- Receiver - UE2: using wireshark

Test with Iperf
- Sender - UE1: iperf -c 224.0.0.1 -u -b 0.1M --bind 10.0.0.1 -t 100
- Receiver - UE2: sudo ./mcreceive 224.0.0.1 5001