How to Implement Cloud RAN in OMNeT++

To implement the Cloud Radio Access Network (Cloud-RAN or C-RAN) in OMNeT++ needs an environment in which the models are the centralized architecture of C-RAN by simulating it. This includes generating a centralized baseband unit (BBU) pool, remote radio heads (RRHs), and the fronthaul network connecting them. To support the C-RAN architecture, we have to extend the INET framework. Here’s a step-by-step implementation of Cloud RAN in OMNeT++:

Step-by-Step Implementation:

Step 1: Install OMNeT++ and INET Framework

1. Download OMNeT++:
   • Download the latest version of OMNeT++.
2. Install OMNeT++:
   • Go through the instruction to install properly on your system..
3. Download and Install INET Framework:
   • The INET framework offers models for internet protocols and is often used with OMNeT++.
   • Install the INET Framework in your computer.

Step 2: Set Up Your Project

1. Create a New OMNeT++ Project:
   • Open the OMNeT++ IDE.
   • Go to File -> New -> OMNeT++ Project.
   • Enter a project name and select the proper options.
2. Set Up Directory Structure:
   • Make certain that the project contains folders like src for source files and simulations for NED files and configuration.
3. Add INET to Your Project:
   • Right-click on project in the Project Explorer.
   • Select Properties -> Project References.
   • Check the box for INET.

Step 3: Define C-RAN Models Using NED

1. Create NED Files:
   • In the src directory, create a new NED file (for instance,  CRANNetwork.ned).
   • Define the network topology in the NED file. Here’s a simple example:

package cran;

import inet.node.inet.StandardHost;

import inet.node.inet.Router;

import inet.node.ethernet.EtherSwitch;

import inet.physicallayer.common.packetlevel.RadioMedium;

import inet.mobility.single.RandomWaypointMobility;

network CRANNetwork

{

parameters:

int numRRHs = default(5);

int numUEs = default(10);

submodules:

radioMedium: RadioMedium {

@display(“p=100,100”);

}

bbuPool: Router {

@display(“p=200,200”);

}

rrh[numRRHs]: StandardHost {

@display(“p=300+100*i,200”);

}

ue[numUEs]: StandardHost {

@display(“p=400+50*i,300”);

mobility.typename = “RandomWaypointMobility”;

}

switch: EtherSwitch {

@display(“p=300,100”);

}

connections allowunconnected:

bbuPool.ethg++ <–> Eth100M <–> switch.ethg++;

for i=0..numRRHs-1 {

rrh[i].ethg++ <–> Eth100M <–> switch.ethg++;

}

for i=0..numUEs-1 {

ue[i].wlan[0] <–> radioMedium <–> rrh[i % numRRHs].wlan[0];

}

}

Step 4: Implement C-RAN Communication Logic

1. Create C++ Modules for BBUs, RRHs, and UEs:
   • Create new C++ classes (e.g., BBUPool.cc, RRH.cc, and UE.cc) in the src directory.
   • Include essential OMNeT++ headers and define C-RAN communication logic.
2. BBU Pool Implementation:

#include <omnetpp.h>

#include “inet/applications/base/ApplicationBase.h”

#include “inet/common/packet/Packet.h”

using namespace omnetpp;

using namespace inet;

class BBUPool : public ApplicationBase

{

protected:

virtual void initialize(int stage) override;

virtual void handleMessageWhenUp(cMessage *msg) override;

void processFronthaul(Packet *pkt);

};

Define_Module(BBUPool);

void BBUPool::initialize(int stage)

{

ApplicationBase::initialize(stage);

}

void BBUPool::handleMessageWhenUp(cMessage *msg)

{

Packet *pkt = check_and_cast<Packet *>(msg);

processFronthaul(pkt);

}

void BBUPool::processFronthaul(Packet *pkt)

{

// Process fronthaul data coming from RRHs

EV << “Processing fronthaul data: ” << pkt->getName() << endl;

// Implement processing logic here

delete pkt;

}

1. RRH Implementation:

#include <omnetpp.h>

#include “inet/applications/base/ApplicationBase.h”

#include “inet/common/packet/Packet.h”

using namespace omnetpp;

using namespace inet;

class RRH : public ApplicationBase

{

protected:

virtual void initialize(int stage) override;

virtual void handleMessageWhenUp(cMessage *msg) override;

void sendFronthaulData();

void handleUEPacket(Packet *pkt);

cMessage *sendEvent = nullptr;

};

Define_Module(RRH);

void RRH::initialize(int stage)

{

ApplicationBase::initialize(stage);

if (stage == INITSTAGE_LOCAL) {

sendEvent = new cMessage(“sendFronthaulData”);

scheduleAt(simTime() + par(“startTime”), sendEvent);

}

}

void RRH::handleMessageWhenUp(cMessage *msg)

{

if (msg == sendEvent) {

sendFronthaulData();

scheduleAt(simTime() + par(“sendInterval”), sendEvent);

} else {

Packet *pkt = check_and_cast<Packet *>(msg);

handleUEPacket(pkt);

}

}

void RRH::sendFronthaulData()

{

// Create and send fronthaul data packet to BBU pool

EV << “Sending fronthaul data” << endl;

Packet *pkt = new Packet(“FronthaulData”);

pkt->setByteLength(par(“dataSize”));

send(pkt, “lowerLayerOut”);

}

void RRH::handleUEPacket(Packet *pkt)

{

// Handle received UE packet

EV << “Received UE packet: ” << pkt->getName() << endl;

// Forward packet to BBU pool or process it

send(pkt, “lowerLayerOut”);

}

1. UE Implementation:

#include <omnetpp.h>

#include “inet/applications/base/ApplicationBase.h”

#include “inet/common/packet/Packet.h”

using namespace omnetpp;

using namespace inet;

class UE : public ApplicationBase

{

protected:

virtual void initialize(int stage) override;

virtual void handleMessageWhenUp(cMessage *msg) override;

void sendUEData();

void handleRRHPacket(Packet *pkt);

cMessage *sendEvent = nullptr;

};

Define_Module(UE);

 

void UE::initialize(int stage)

{

ApplicationBase::initialize(stage);

if (stage == INITSTAGE_LOCAL) {

sendEvent = new cMessage(“sendUEData”);

scheduleAt(simTime() + par(“startTime”), sendEvent);

}

}

void UE::handleMessageWhenUp(cMessage *msg)

{

if (msg == sendEvent) {

sendUEData();

scheduleAt(simTime() + par(“sendInterval”), sendEvent);

} else {

Packet *pkt = check_and_cast<Packet *>(msg);

handleRRHPacket(pkt);

}

}

void UE::sendUEData()

{

// Create and send UE data packet to RRH

EV << “Sending UE data” << endl;

Packet *pkt = new Packet(“UEData”);

pkt->setByteLength(par(“dataSize”));

send(pkt, “lowerLayerOut”);

}

void UE::handleRRHPacket(Packet *pkt)

{

// Handle received RRH packet

EV << “Received RRH packet: ” << pkt->getName() << endl;

delete pkt;

}

Step 5: Integrate C-RAN Modules into Network Model

1. Modify NED File to Use C-RAN Modules:
   • Use the custom BBU pool, RRH, and UE application modules by updating the NED file :

package cran;

import inet.node.inet.StandardHost;

import inet.node.inet.Router;

import inet.node.ethernet.EtherSwitch;

import inet.physicallayer.contract.packetlevel.IRadioMedium;

import inet.physicallayer.common.packetlevel.RadioMedium;

network CRANNetwork

{

parameters:

int numRRHs = default(5);

int numUEs = default(10);

submodules:

radioMedium: RadioMedium {

@display(“p=100,100”);

}

bbuPool: Router {

@display(“p=200,200”);

@children:

wlan[0].radio.transmitter.typename = “BBUPool”;

wlan[0].radio.receiver.typename = “BBUPool”;

}

rrh[numRRHs]: StandardHost {

@display(“p=300+100*i,200”);

@children:

wlan[0].radio.transmitter.typename = “RRH”;

wlan[0].radio.receiver.typename = “RRH”;

}

ue[numUEs]: StandardHost {

@display(“p=400+50*i,300”);

mobility.typename = “RandomWaypointMobility”;

@children:

wlan[0].radio.transmitter.typename = “UE”;

wlan[0].radio.receiver.typename = “UE”;

}

switch: EtherSwitch {

@display(“p=300,100”);

}

connections allowunconnected:

bbuPool.ethg++ <–> Eth100M <–> switch.ethg++;

for i=0..numRRHs-1 {

rrh[i].ethg++ <–> Eth100M <–> switch.ethg++;

}

for i=0..numUEs-1 {

ue[i].wlan[0] <–> radioMedium <–> rrh[i % numRRHs].wlan[0];

}

}

Step 6: Configure Simulation Parameters

1. Create omnetpp.ini:
   • Create an omnetpp.ini file in the simulation directory.
   • Describe simulation parameters like duration and network parameters:

[General]

network = CRANNetwork

sim-time-limit = 100s

# Mobility

**.ue[*].mobility.bounds = “0,0,1000,1000”

# BBU pool application parameters

**.bbuPool.udpApp.startTime = uniform(0s, 10s)

**.bbuPool.udpApp.sendInterval = exponential(1s)

**.bbuPool.udpApp.messageSize = 256B

**.bbuPool.udpApp.localPort = 1000

**.bbuPool.udpApp.destPort = 2000

# RRH application parameters

**.rrh[*].udpApp.startTime = uniform(0s, 10s)

**.rrh[*].udpApp.sendInterval = exponential(1s)

**.rrh[*].udpApp.dataSize = 256B

**.rrh[*].udpApp.localPort = 3000

**.rrh[*].udpApp.destPort = 4000

# UE application parameters

**.ue[*].udpApp.startTime = uniform(0s, 10s)

**.ue[*].udpApp.sendInterval = exponential(1s)

**.ue[*].udpApp.dataSize = 256B

**.ue[*].udpApp.localPort = 5000

**.ue[*].udpApp.destPort = 6000

Step 7: Build and Run the Simulation

1. Build the Project:
   • In the OMNeT++ IDE, right-click on the  project and select Build Project.
2. Run the Simulation:
   • Go to Run -> Run Configurations.
   • Build a new run configuration for the project and run the simulation.

Step 8: Analyze Results

1. View Simulation Results:
   • Use OMNeT++’s tools to analyze the results only after the simulation is done.
   • Open the ANF (Analysis Framework) to visualize and interpret the data.

In the approach, we help you set up a basic C-RAN simulation in OMNeT++ using the INET framework by giving you the essential details. For more information about this script, we can guide you whenever you need. Engage with us for optimal simulation and project implementation on Cloud RAN utilizing OMNeT++, delivered by leading developers for your initiatives. We specialize in the INET framework to support your projects.