View source for 4G: OpenAirInterface dari OpenCell

Sumber: https://open-cells.com/index.php/2019/09/22/all-in-one-openairinterface/

Yang digunakan

* Ubuntu 18.04 64bit
* Ettus B210 (kalau ada), kalau tidak ada kita coba simulasi physical.

==Download Source OAI EPC==

 sudo apt install git


Sebagai user biasa, download config mods dari opencells

 cd ~
 wget https://open-cells.com/opencells-mods-20190923.tgz
 tar xf opencells-mods-20190923.tgz

Download and patch EPC

 cd ~
 wget https://open-cells.com/d5138782a8739209ec5760865b1e53b0/openair-cn.tgz
 tar xf openair-cn.tgz
 cd openair-cn
 git checkout develop

Apply the patch:

 git apply ~/opencells-mods/EPC.patch


What is in the patch file:

* Add Ubuntu 18.04 for compilation and fix some bugs
* Remove link between Linux host name and LTE diameter protocol configuration
* Add usage of the input address for the SGW input socket
modify the freediameter S6a interface to fix a wrong OAI parameter
* No kernel module patch is required: generic Ubuntu kernel 18.04 works fine with OAI
* separate ASN.1 compiler installation to be compatible with other OpenAir components on the same machine (ans1c version is different for eNB and gNB)

Install third party SW for EPC

 cd ~/openair-cn
 source oaienv
 cd scripts
 ./build_hss -i

 Do you want to install freeDiameter 1.2.0: yes

Jika ada kesalahan, coba

 sudo apt --fix-broken install
 cd ~/openair-cn
 source oaienv
 cd scripts
 ./build_hss -i

Untuk ubuntu 18.04, set back legacy mysql security level

 sudo mysql -u root
 USE mysql;
 UPDATE user SET plugin='mysql_native_password' WHERE User='root';
 FLUSH PRIVILEGES;
 quit

 sudo systemctl restart mysql.service

Default username root, password "kosong"

Install 3PP SW untuk mme dan spgw

 sudo apt fix-broken install
 cd ~/openair-cn
 source oaienv
 cd scripts
 ./build_mme -i

 Do you want to install freeDiameter 1.2.0 <y/N>: yes
 Do you want to install asn1c rev 1516 patched? <y/N>: yes
 Do you want to install libgtpnl ? <y/N>: yes
 wireshark permissions: as you prefer


 cd ~/openair-cn
 source oaienv
 cd scripts
 ./build_spgw -i
 Do you want to install libgtpnl ? <y/N>: no

==Compile the EPC nodes==

Kalau gagal di ulang lagi saja.

 cd ~/openair-cn
 source oaienv
 cd scripts
 ./build_hss
 ./build_mme
 ./build_spgw

Jika ada masalah compile, cek string "error:" di,

 openair-cn/build/log

==Download & Compile the eNB on 18.04==

 cd ~
 git config --global user.name "Onno"
 git config --global user.email "onno@indo.net.id"
 git clone https://gitlab.eurecom.fr/oai/openairinterface5g.git
 cd ~/openairinterface5g
 git checkout develop

We tested with commit edb74831dabf79686eb5a92fbf8fc06e6b267d35
Build in two steps
 source oaienv  
 ./cmake_targets/build_oai -I  # install SW packages from internet
 ./cmake_targets/build_oai -I 

 ./cmake_targets/build_oai -I -w USRP --eNB
 ./cmake_targets/build_oai -I -w USRP --eNB --UE # compile eNB and UE

==Our Network setup description==

I’ve made a simple configuration for this all-in-one setup.

Each node is on a separate IP address, this address is used for all it’s interfaces. In our case of all-in-one, we take addresses on the loopback: this will be fine on all your machines.

 HSS is on localhost: 127.0.0.1
 eNB is on 127.0.0.10
 MME is on 127.0.0.20
 SPGW is on 127.0.0.30

The LTE diameter configuration is now isolated from Linux hostname.

realm for our EPC: “OpenAir5G.Alliance”, so, full distinguish names (FQDN) are:
 hss.OpenAir5G.Alliance,
 mme.OpenAir5G.Alliance

==Install this configuration for eNB==

In your eNB configuration file, the network is now fixed, as lo interface always exists and our computer internal addresses also:

  ////////// MME parameters:
  mme_ip_address = ( { ipv4 = "127.0.0.20";
  ipv6 = "192:168:30::17";
  active = "yes";
  preference = "ipv4";
  }
  );
 
 NETWORK_INTERFACES : 
  {
  ENB_INTERFACE_NAME_FOR_S1_MME = "lo";
  ENB_IPV4_ADDRESS_FOR_S1_MME = "127.0.0.10/8"; 
 
  ENB_INTERFACE_NAME_FOR_S1U = "lo";
  ENB_IPV4_ADDRESS_FOR_S1U = "127.0.0.10/8";
  ENB_PORT_FOR_S1U = 2152; # Spec 2152
  };

In the eNB config file, you need also to set the MCC and MNC as per your SIM card:

 tracking_area_code = “1”;
 mobile_country_code = “208”;
 mobile_network_code = “92”;

And obviously, your radio parameters.

Wwe tested with USRP B210 20MHz band, Huawei E3272 UE, a cavity duplexer a simple antenna, about 1 meter distance UE/eNB antenna with this file: 

 ~/opencells-mods/enb.10MHz.b200

if you use the OpenAir UE, a sim card file that match our hss database example: opencells-mods/sim.conf. We will make another tutorial to use together OpenAir UE and rf board simulation

Install this configuration for EPC
For the EPC, we install in OAI default directory: /usr/local/etc/oai

 sudo mkdir -p /usr/local/etc/oai
 sudo cp -rp ~/opencells-mods/config_epc/* /usr/local/etc/oai
 cd openair-cn; source oaienv; cd scripts
 ./check_hss_s6a_certificate /usr/local/etc/oai/freeDiameter hss.OpenAir5G.Alliance
 ./check_mme_s6a_certificate /usr/local/etc/oai/freeDiameter mme.OpenAir5G.Alliance

Only the SGi output to internet need to be configured.

In /usr/local/etc/oai/spgw.conf,
your should set the Ethernet interface that is connected to Internet, and,
to tell to the PGW to implement NAPT for the UE traffic

 PGW_INTERFACE_NAME_FOR_SGI = "enp3s0"; 
 PGW_MASQUERADE_SGI = "yes";

For the SIM card, you’ll have more to do:   

* SIM MCC/MNC should be duplicated in a couple of files
* eNB: See above in eNB configuration chapter
* MME file: /usr/local/etc/oai/mme.conf to update
 GUMMEI_LIST = ( MCC="208" ; MNC="92"; MME_GID="4" ; MME_CODE="1"; } );
 TAI_LIST = ({MCC="208" ; MNC="92"; TAC = "1"; } );
 HSS

Configure the password for MySQL
in /usr/local/etc/oai/hss.conf, set password as the password you created during MySQL installation
A HSS database in text is in: ~/opencells-mods/opencells_db.sql
We don’t use phpmyadmin: we load the database from a ascii file
It is pre-configured with the

 mme id

10 users is network 208/92 (a French test network) are also created (don’t use 3GPP test network: 001/01: the mme fails when MCC starts by “0”)

Each time you import this db, it erases the entire database
(example: you set mysql password to “linux”)
~/opencells-mods/hss_import 127.0.0.1 root linux oai_db ~/opencells-mods/opencells_db.sql
We use to modify the db by updating this file with regular text editor,
then we re-load the entire database,
but, if you prefer, usage of http://localhost/phpmyadmin is fine.
if you modified the hss db directly, we offer a export script:

 ~/opencells-mods/hss_export

The important values to set are:
* table pdn:
all IMSI are listed, with the APN: these values are in UE/USIM
* table users:
all IMSI, key (Ki) and OPc must be the same in USIM card
Sqn increments automatically  when the UE authenticate in both USIM and HSS DB: it should be set as per USIM internal incrementation

SIM card update
Open cells UICC and card reader will  be supported
Final test and verification
open 4 terminal windows

in each window

 cd openair-cn; source oaienv; cd scripts; ./run_hss
 cd openair-cn; source oaienv; cd scripts; ./run_mme
 cd openair-cn; source oaienv; cd scripts; sudo -E ./run_spgw
 sudo bash
 cd ~/openairinterface5g; source oaienv
 cd cmake_targets/lte_build_oai/build
./lte-softmodem -O ~/opencells-mods/enb.10MHz.b200

Connect the UE, it should attach to network and be able to reach internet through OAI network.

If the UE attaches, but you don’t have internet access, verify phone configuration: enable data in config->sim and verify the APN value

Issues related to CPU power
If you reach performance issues: USRP/UHD prints “LLLLL” or the process exits “problem with samples”, OVERFLOW, …

The first case is to verify the USRP dialogs over USB3 (not USB2): the process must report:

 Found USRP B200
 -- Detected Device: B200
 -- Operating over USB 3.

For OAI source code, we wrote improvements and some hints for UE performance last year. The Linux/Ubuntu advises can be applied to the eNB:

 https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/setup-for-real-time-performance

We may make later a post for eNB (OAI/eNB can reach much better performance than today develop branch, but it require to enhance parts of the source code).

We re-built this procedure from scratch and tested i5-6600K.

On the i5-6600K, we obtained stable performance at maximum traffic over 20MHz, transmission mode 1 (SISO), duplexer, antenna, E3372 UE (one single UE) over-the-air 10 cm distance :

==Referensi==

* https://open-cells.com/index.php/2019/09/22/all-in-one-openairinterface/