ns-o-ran-flexric

Project Introduction

Given the importance of obtaining a capable and fully open-source platform for xApp operation testing, especially for the complex use-cases. Orange Innovation Egypt(OIE) team Successfully integrated FlexRIC from EURECOM with ns-O-RAN simulator that originally developed by the institute for the Wireless Internet of Things (WIoT) and Mavenir. The team updated the ns-O-RAN simulator to be a fully compliant with E2AP v1.01 and KPM v3. This platform will pave the way to test the use-cases that need a rich LTE/5G simulator to be verified. The original project of ns-O-RAN in OpenRAN-Gym.

Code Structure

The ns-O-RAN is composed by three main components, as shown in the figure below:

• The e2sim software, which was originally developed by the OSC community.
• The ns3-mmWave version, which was originally developed by the University of Padova and NYU.
• The ns-O-RAN module, developed by Northeastern University and Mavenir, which is basically an external module that can be plugged in ns-3 and uses the e2sim to create a SCTP connection with the RIC.

Main Updates

The implemetation of the E2APv1.01 includes:

1. E2 Setup request

   - Edit the RAN Function IDs for KPM and RC ​
   - Reformat the size of the message to match FlexRIC (62 byte)​
   - Update the KPM ASN and model to KPM v3 ​
   

2. E2 Subscription Response ​

   - Add RAN Function NotAdmitted IE to the message​
   - Update the message to match KPM v3.0​
   - Fill New RIC indication messages formats (Format 3 )​
   

3. RIC Control Acknoweldege ​

      -Implemented from scratch
   

4. RIC Control Request ​

      - Update the message to match E2SM RC v1.01​
   

5. RIC Subscription delete request/response

   - Implemented from scratch
   

6. RIC Subscription modification response (In-Prograss)

    - Implemented from scratch
   

7. RIC Subscription modification confirm (In-Prograss)

    - Implemented from scratch
   

The implementation of KPM and RC

1. Update the KPM ASN and model to KPM v3.00

2. Update the RC ASN and model to RC v1.02 (In-Prograss)

Requirments

First start with the installation of the prerequisites. In Ubuntu 20.04 LTS, these can be installed with:

sudo apt-get update
# Requirements for e2sim
sudo apt-get install -y build-essential git cmake libsctp-dev autoconf automake libtool bison flex libboost-all-dev 
# Requirements for ns-3
sudo apt-get install g++ python3

Installation Instructions

The prepation of enviroment for running testing examples can be done when 'near-RIC' is initialized, as sequence diagram is represented below:

1. FlexRiC Installation Instructions

The first release for ns-O-RAN-flexric proejct is working with a mature commit for flexric, you MUST follow installtion and deployment instructions, under commit number d3ff8791 before use the simulator.

2. ns-O-RAN-flexric Installation Instructions

First you need to clone the project

git clone --recurse-submodules https://github.com/Orange-OpenSource/ns-O-RAN-flexric

Note

If you made a clone before and there are new updates so you need to make recursive pull

git pull --recurse-submodules https://github.com/Orange-OpenSource/ns-O-RAN-flexric

To set up the environment for ORAN E2 simulator, navigate to the /e2sim-kpmv3/e2sim directory. Create a new directory named build. Then execute the script build_e2sim.sh with the argument 3 to enable LOG_LEVEL (DEBUG). This is useful to debug the exchange of the messages between the ns-3 and the RIC, but also there are a different debug levels that can be setup. These levels are summarized in the table below.

cd /e2sim-kpmv3/e2sim/
mkdir build
sudo ./build_e2sim.sh 3

Log Level e2Sim	Value	Description
LOG_LEVEL_UNCOND	0	Show only the uncoditional logs.
LOG_LEVEL_ERROR	1	Show all the previous logs plus failures on the e2Sim side (such as errors on encoding)
LOG_LEVEL_INFO	2 (default)	Show all the previous logs plus the some info about the size of the messages
LOG_LEVEL_DEBUG	3	Show all the possible logs including the xer_printing of the ASN1.C messages

This last command shall configure the cmake project and install the e2sim on the system. Its main actions are also in the aforementioned Dockerfile that we report here to clarify the operations conducted by the script:

RUN mkdir /workspace/e2sim/e2sim/build
WORKDIR /workspace/e2sim/e2sim/build # Creation and cd on the build directory
RUN cmake .. -DDEV_PKG=1 -DLOG_LEVEL=${log_level_e2sim} # build of the project with the LOG_LEVEL desired

RUN make package # Creation of the package
RUN echo "Going to install e2sim-dev"
RUN dpkg --install ./e2sim-dev_1.0.0_amd64.deb # Installation of the generated package on the system
RUN ldconfig  # library update to make the package linkable from ns-3 without rebooting the machine

Navigate to ns3-mmWave project:

cd ns-3-mmwave-oran

At this step the software in place to configure and build ns-3:

./waf configure --enable-examples --enable-tests
./waf build

Usage/deployment

Scenario Zero

Finally, run an example ns-3 scenario called Scenario Zero for testing purpose. This scenario features a Non-StandAlone (NSA) 5G setup in which, its have one LTE eNB positioned in the center of the scenario and four gNBs around it with an inter site distance of 1000 between the eNB and each gNB. You can run the scenario after done the following steps first:

1. First you must be done the installation instructions for the flexric mentiond in the above section 'FlexRiC Installation Instructions'
2. Second you must done the building steps for ns3-oran simulator section, to build an 'e2sim' and 'ns-3-mmwave-oran' waf.
3. The last thing, after you done the building process, it's time to run the scenario-zero as a first test case.
   1. Navigate to '/path/to/flexric/build/examples/ric/' and then run './nearRT-RIC'.
   2. Navigate to '/path/to/ns-3-mmwave-oran' and then run './waf --run scratch/scenario-zero.cc'
   3. Navigate to '/path/to/flexric/build/examples/xApp/c/kpm_rc' and then run './xapp_kpm_rc'.

And if everything goes as intended we should be able to see in order the following messages as shown in the Wireshark snapshot below:

1. E2 Setup Request (ns-O-RAN to E2 Term on RIC)
2. E2 Setup Response (E2 Term on RIC to ns-O-RAN)
3. E2 Subscription Request (xApp to ns-O-RAN through E2 Term on RIC)
4. E2 Subscription Response (ns-O-RAN to xApp through E2 Term on RIC)
5. RIC Indication (ns-O-RAN to xApp through E2 Term on RIC)
6. RIC Control Request (xApp to RIC to ns-O-RAN)
7. RIC Control Ack (ns-O-RAN to xApp through E2 Term on RIC)
8. RIC Subscription Delete Request (xApp to RIC to ns-O-RAN)
9. RIC Subscription Delete Response (ns-O-RAN to xApp through E2 Term on RIC)

Contributers

• Mina Yonan, Orange Innovation Egypt, [email protected]
• Mostafa Ashraf, Orange Innovation Egypt, [email protected]

Liscence

GNU GENERAL PUBLIC LICENSE