How OAI Uses and Establishes Configuration Files

Introduction

OpenAirInterface (OAI) uses configuration files extensively to tailor the system’s behavior according to specific deployment needs. This section will walk through the process of obtaining the source code, understanding the directory structure, and using configuration files effectively.

Obtain the OAI Source Code

The initial step in setting up OAI is to download the source code. This can be achieved by cloning the OAI repository from GitHub:

git clone https://github.com/OPENAIRINTERFACE/openairinterface5g.git

Understand the Directory Structure

The OAI source tree consists of multiple directories, each serving specific purposes related to the build and configuration process:

  • cmake_targets: Contains build scripts and CMake files crucial for compilation.

    • CMake File: Manages the build process across different platforms using a compiler-independent method.

    • Build Script: Named build_oai, this script facilitates the creation of specific build trees from the CMake configurations.

    • Subdirectories: Includes various directories like at_commands, autotests, and tools, each dedicated to specific development or testing tasks.

    • Configuration Files: Stores essential parameters for the build process.

    • Runtime Configuration Files: Utilized during the runtime to configure OAI software dynamically.

Use the Build Script

A script named build_oai is provided to simplify the building of OAI components:

./build_oai -I      # This command installs the dependencies
./build_oai         # This command builds the OAI system

This script supports various build options:

  • Simulation: Use the option –build-simulation to create simulation binaries.

  • RIC Agent Support: Enable with –build-ric-agent for building OAI with RIC agent functionalities.

  • Physical Simulators: Use –phy-simulators to build physical simulator components.

Understand Configuration Files

Configuration files in OAI are crucial for setting operational parameters:

  • configmodule_interface_t Structure: This data structure stores all necessary configuration details.

    • Configuration Module: Manages command line parameters and loads configuration dynamically at runtime.

    • Function Implementation: Includes methods like config_get, config_getlist, and optionally config_end for managing configurations.

Set Configuration Options

Configuration options can be set by modifying the source code or via the command line when starting the OAI applications:

./lte-softmodem -O /path/to/config_file.conf

This command starts the LTE soft modem using the specified configuration file.

Compile and Run

Once the configuration files are set up, compile and run the OAI software:

cd cmake_targets
./build_oai
./lte-softmodem -O /path/to/your_config_file.conf

The software is now ready to operate based on the specified configurations.

Conclusion

Setting up and using configuration files in OAI is a structured process that enhances the flexibility and adaptability of the system. By following these steps, developers can customize OAI to meet their specific needs, from basic simulations to complex real-world deployments.