How to Implement Channel Scheduling in ns3

To implement channel scheduling in ns3, we need to define that how multiple nodes or devices share the communication medium. In wireless networks, to avoid collisions nodes will coordinate their access to the shared channel and ensure that bandwidth is efficiently used. This type of channels are mainly used in the wireless networks. Below given steps will guide on how to implement channel scheduling in ns3.

Step-by-Step Guide to implement

1. Install ns-3: Make sure that ns3 is installed on the system.
2. Set Up Your Simulation Environment: Create a new simulation script or modify an existing one. The script should include necessary modules such as network, internet, and mobility.
3. Define Network Topology: Set up the network topology by defining the nodes, channels, and devices.

NodeContainer nodes;

nodes.Create(3);

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.SetChannel(channel.Create());

WifiHelper wifi = WifiHelper::Default();

WifiMacHelper mac;

Ssid ssid = Ssid(“ns-3-ssid”);

mac.SetType(“ns3::StaWifiMac”, “Ssid”, SsidValue(ssid),

“ActiveProbing”, BooleanValue(false));

 

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

Configure Internet Stack: Install the internet stack on the nodes and assign IP addresses.

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

address.SetBase(“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces = address.Assign(devices);

Implement Channel Scheduling: We need to create a custom channel access mechanism. One way to do this is to modify the MAC layer to include a scheduling algorithm. Below is an example of how to use the Round Robin scheduling mechanism.

class RoundRobinScheduler : public Object

{

public:

RoundRobinScheduler() : m_currentNode(0) {}

void Schedule(Ptr<NetDevice> device)

{

// Implement Round Robin scheduling logic here

m_currentNode = (m_currentNode + 1) % m_totalNodes;

Ptr<Node> node = device->GetNode();

// Code to schedule access for node

}

private:

uint32_t m_currentNode;

uint32_t m_totalNodes;

};

Attach the Scheduler to the MAC Layer: Modify the MAC layer to use the custom scheduler.

class CustomWifiMac : public RegularWifiMac

{

public:

CustomWifiMac() : m_scheduler(CreateObject<RoundRobinScheduler>()) {}

virtual void DoInitialize() override

{

// Attach the scheduler

m_scheduler->Schedule(GetDevice());

RegularWifiMac::DoInitialize();

}

private:

Ptr<RoundRobinScheduler> m_scheduler;

};

Integrate Custom MAC with Devices: Use the custom MAC layer in the devices.

mac.SetType(“ns3::CustomWifiMac”,

“Ssid”, SsidValue(ssid),

“QosSupported”, BooleanValue(true));

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

Run the Simulation: Set up traffic generators, configure logging, and run the simulation.

Simulator::Run();

Simulator::Destroy();

Example Code

Here’s a minimal example of how you might set up a simple channel scheduling scenario:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/wifi-module.h”

#include “ns3/mobility-module.h”

#include “ns3/applications-module.h”

using namespace ns3;

int main(int argc, char *argv[])

{

CommandLine cmd;

cmd.Parse(argc, argv);

NodeContainer nodes;

nodes.Create(3);

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.SetChannel(channel.Create());

WifiHelper wifi = WifiHelper::Default();

WifiMacHelper mac;

Ssid ssid = Ssid(“ns-3-ssid”);

mac.SetType(“ns3::StaWifiMac”,

“Ssid”, SsidValue(ssid),

“ActiveProbing”, BooleanValue(false));

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

address.SetBase(“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces = address.Assign(devices);

// Implement and attach the scheduler here

Simulator::Run();

Simulator::Destroy();

return 0;

}

Over all, we had completely discussed about the Channel scheduling implementation in ns3, which involves communication medium that shared by multiple nodes and devices. And also configuring internet stack, attaching the scheduler, integrating custom MAC we can implement it.

A range of project concepts related to Channel Scheduling in the ns3 tool is being implemented for students. For optimal outcomes, engage with ns3simulation.com.