---
title: OAI with COTS UE
tags: "OAI"
---
# 5G NR Platform

[TOC]

## Required
- Hardware
- CPU: i5-9400
- OS: Ubuntu 18.04LTS
- UE: Oppo reno 5G
- USRP B210, B200mini
- Software
- Core Network: [Open5gs](https://open5gs.org/open5gs/)
- gNB: [OpenAirInterface](https://gitlab.eurecom.fr/oai/openairinterface5g)
- branch: develop
- commit: 3bc86d69c0c63399ed7adf0f6d40ad68557877c5
- Band 78, 106 RB

## Build the gNB

### Clone the OpenAirInterface

Clone the project form the gitlab

git clone https://gitlab.eurecom.fr/oai/openairinterface5g/
cd openairinterface5g
git checkout 3bc86d69c0

Build OAI gNB executable

source oaienv
cd cmake_targets/
export BUILD_UHD_FROM_SOURCE=True
./build_oai -I -w USRP --gNB

> NOTICE: Do NOT run with `sudo`

Modify the config file: `openairinterface5g/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.fr1.106PRB.usrpb210.conf`

@@ -10,8 +10,10 @@
     gNB_name  =  "gNB-OAI";

     // Tracking area code, 0x0000 and 0xfffe are reserved values
-    tracking_area_code  =  1;
-    plmn_list = ({ mcc = 208; mnc = 99; mnc_length = 2; snssaiList = ({ sst = 1; sd = 0x1; }) });
+    tracking_area_code  =  2;
+    plmn_list = ({ 
+       mcc = 001; 
+       mnc = 01; 
+       mnc_length = 2; 
+       snssaiList = ({ 
+           sst = 1;
+           # sd = 0x1;
+       }) 
+   });

     nr_cellid = 12345678L;

@@ -166,7 +168,7 @@


     ////////// AMF parameters:
-    amf_ip_address      = ( { ipv4       = "192.168.70.132";
+    amf_ip_address      = ( { ipv4       = "127.0.0.5";
                               ipv6       = "192:168:30::17";
                               active     = "yes";
                               preference = "ipv4";
@@ -177,9 +179,9 @@
     NETWORK_INTERFACES :
     {
         GNB_INTERFACE_NAME_FOR_NG_AMF            = "demo-oai";
-        GNB_IPV4_ADDRESS_FOR_NG_AMF              = "192.168.70.129/24";
+        GNB_IPV4_ADDRESS_FOR_NG_AMF              = "127.0.32.56/8";
         GNB_INTERFACE_NAME_FOR_NGU               = "demo-oai";
-        GNB_IPV4_ADDRESS_FOR_NGU                 = "192.168.70.129/24";
+        GNB_IPV4_ADDRESS_FOR_NGU                 = "127.0.32.56/8";
         GNB_PORT_FOR_S1U                         = 2152; # Spec 2152
     };

## Install Open5gs

### Install Open5GS

Run the following command to install the open5gs

sudo apt update
sudo apt install software-properties-common
sudo add-apt-repository ppa:open5gs/latest
sudo apt update
sudo apt install open5gs

Check if all daemons are alive(active):

sudo systemctl | grep open5gs-

Setup 5G core network: edit `/etc/open5gs/amf.yaml`

amf:
    sbi:
      - addr: 127.0.0.5
        port: 7777
     ngap:
      - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 999
-          mnc: 70
+          mcc: 001 # set your PLMN-MCC
+          mnc: 01  # set your PLMN-MNC
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 999
-          mnc: 70
-        tac: 1
+          mcc: 001 # set your PLMN-MCC
+          mnc: 01  # set your PLMN-MNC
+        tac: 2 # should match the TAC used by your gNB
     plmn_support:
       - plmn_id:
-          mcc: 999
-          mnc: 70
+          mcc: 001 # set your PLMN-MCC
+          mnc: 01  # set your PLMN-MNC
         s_nssai:
           - sst: 1
     security:

Restart corresponding daemons

sudo systemctl restart open5gs-amfd
sudo systemctl restart open5gs-upfd

Monitor virtual network interface card

sudo tcpdump -i ogstun

Create a text file `~/restart_5gs.sh` and paste the following:

# stop 5gs
sudo systemctl stop open5gs-mmed
sudo systemctl stop open5gs-sgwcd
sudo systemctl stop open5gs-smfd
sudo systemctl stop open5gs-amfd
sudo systemctl stop open5gs-sgwud
sudo systemctl stop open5gs-upfd
sudo systemctl stop open5gs-hssd
sudo systemctl stop open5gs-pcrfd
sudo systemctl stop open5gs-nrfd
sudo systemctl stop open5gs-ausfd
sudo systemctl stop open5gs-udmd
sudo systemctl stop open5gs-pcfd
sudo systemctl stop open5gs-nssfd
sudo systemctl stop open5gs-bsfd
sudo systemctl stop open5gs-udrd
# restart 5gs
sudo systemctl restart open5gs-smfd
sudo systemctl restart open5gs-amfd
sudo systemctl restart open5gs-upfd
sudo systemctl restart open5gs-nrfd
sudo systemctl restart open5gs-ausfd
sudo systemctl restart open5gs-udmd
sudo systemctl restart open5gs-pcfd
sudo systemctl restart open5gs-nssfd
sudo systemctl restart open5gs-bsfd
sudo systemctl restart open5gs-udrd

Give the permission:

chmod +x ~/restart_5gs.sh

### Add the IMSI to the database

Insert UE information to database

Download this [code](https://github.com/open5gs/open5gs/blob/main/misc/db/open5gs-dbctl) to any folder you like

curl https://raw.githubusercontent.com/open5gs/open5gs/main/misc/db/open5gs-dbctl > ./open5gs-dbctl
chmod +x ./open5gs-dbctl
./open5gs-dbctl help

Add UE information. (The subscription is added to database with default apn `internet`. I suggest you stick with the default apn until you get everthing working)

# add {imsi key opc}
./open5gs-dbctl add 001010000000093 465B5CE8B199B49FAA5F0A2EE238A6BC E8ED289DEBA952E4283B54E88E6183CA

## Run the Core Network and gNB

### Establish the iptable

Run the following command to establish the iptable for forwarding the traffic.

sudo sysctl -w net.ipv4.ip_forward=1
sudo iptables -I INPUT --source 10.45.0.0/16 -j ACCEPT
sudo iptables -t nat -I POSTROUTING --out-interface <your NIC> -j MASQUERADE
sudo iptables -I FORWARD --in-interface <your NIC> --out-interface ogstun -j ACCEPT
sudo iptables -I FORWARD --in-interface ogstun --out-interface <your NIC> -j ACCEPT

> Remember to edit the network interface card.

### Run the Core Network

Open a terminal for running the Core Network

~/restart_5gs.sh && sudo tail /var/log/open5gs/amf.log -f

### Run the gNB

Open another terminal for running the gNB.

cd ~/openairinterface5g/cmake_targets/ran_build/build
sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.fr1.106PRB.usrpb210.conf -E --sa

Once gNB is connected to core network successfully, you should something like this in the log of core network:

[amf] INFO: [Added] Number of gNBs is now 1 (../src/amf/context.c:878)
[amf] INFO: gNB-N2[192.168.32.100] max_num_of_ostreams : 2 (../src/amf/amf-sm.c:700)

## Go to a TA for COTS UE

Turn on the airplane mode first. Turn off after run the core network and gNB.

Use browser to visit [fast.com](https://fast.com).

The speed need to close to **15Mbps**.