After the build simplification, the basic simulator is available directly from the standard build.
```bash
$ source oaienv
$ cd cmake_targets
$ ./build_oai --eNB--UE
```
Both eNB (lte-softmodem) and UE (lte-uesoftmodem) are present on `cmake_targets/ran_build/build` folder.
More details are available on the [build page](BUILD.md).
# 2. Running the basic simulator.
The basic simulator is a oai device replacing the radio heads (for example the USRP device). It allows connecting the oai UE and the oai eNodeB through a network interface carrying the time-domain samples, getting rid of over the air unpredictable perturbations.
This is the ideal tool to check signal processing algorithms and protocols implementation and having debug sessions without any HW radio equipment.
The main limitations are:
- A single OAI UE will connect to the OAI eNB
- No channel noise
## 2.1. Starting eNB
The basic simulator is able to run with a connected EPC or without any (the so-called "noS1" mode).
After you have [built the softmodem executables](BUILD.md) you can set your default directory to the build directory `cmake_targets/ran_build/build/` and start testing some use cases. Below, the description of the different oai functionalities should help you choose the oai configuration that suits your need.
# Basic Simulator
See the [dedicated page](BASIC_SIM.md).
# RF Simulator
The rf simulator is a oai device replacing the radio heads (for example the USRP device). It allows connecting the oai UE (LTE or 5G) and respectively the oai eNodeB or gNodeB through a network interface carrying the time-domain samples, getting rid of over the air unpredictable perturbations. This is the ideal tool to check signal processing algorithms and protocols implementation. The rf simulator has some preliminary support for channel modeling.