How to Begin Implement Network Aggregate utility in NS3

To implement and analyze the Network Aggregate Utility using NS3, we can describe the utility function, which computes the performance of network according to the certain parameters. The aggregate utility is the total amount of utilities donated in the network with individual users or flows. Here’s a simple guide to begin implementing the Network Aggregate Utility using NS3.

Steps to Implement Network Aggregate Utility in NS3

  1. Understand Network Aggregate Utility
  • Definition: Aggregate utility denotes the entire performance or satisfaction of every user within the network.
  • Utility Function:
    • A utility function (UUU) calculates the satisfaction or user/flow performance depends on specific metrics such as throughput, delay, or fairness.
    • General utility functions are:
      • Throughput Utility: U(x)=log⁡(1+x)U(x) = \log(1 + x)U(x)=log(1+x) in which xxx is the throughput of a user.
      • Fairness Utility: U(x)=xα,  0<α≤1U(x) = x^{\alpha}, \; 0 < \alpha \leq 1U(x)=xα,0<α≤1 where α\alphaα changes the weight of fairness.
  • Aggregate Utility: Aggregate Utility=∑i=1NU(xi)\text{Aggregate Utility} = \sum_{i=1}^N U(x_i)Aggregate Utility=i=1∑N​U(xi​) where NNN is the number of users/flows.
  1. Set Up NS3 Simulation Environment
  1. Install NS3:
    • Make sure that we have installed NS3 and working properly. We can download it on the system.
  2. Define a Network Scenario:
    • Make a network topology that contains numerous flows or users like a wireless or point-to-point network.
  1. Define the Utility Function
  • Select the utility function depends on the network scenario and performance parameters to estimate.
  1. Implement Aggregate Utility Calculation

Here’s a sample script of NS3 for computing the aggregate utility rely on throughput.

Example Script: Aggregate Utility in NS3

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

#include “ns3/flow-monitor-helper.h”

using namespace ns3;

class UtilityCalculator {

public:

UtilityCalculator() : m_aggregateUtility(0.0) {}

void AddFlowUtility(double throughput) {

double utility = std::log(1 + throughput); // Logarithmic utility function

m_aggregateUtility += utility;

NS_LOG_UNCOND(“Flow Throughput: ” << throughput / 1e6 << ” Mbps, Utility: ” << utility);

}

void CalculateAggregateUtility() {

NS_LOG_UNCOND(“Aggregate Utility: ” << m_aggregateUtility);

}

private:

double m_aggregateUtility;

};

UtilityCalculator utilityCalculator;

void MonitorThroughput(Ptr<FlowMonitor> monitor, double simulationTime) {

FlowMonitor::FlowStatsContainer stats = monitor->GetFlowStats();

for (auto const &flow : stats) {

double throughput = (flow.second.rxBytes * 8.0) / (simulationTime); // Throughput in bits per second

utilityCalculator.AddFlowUtility(throughput);

}

utilityCalculator.CalculateAggregateUtility();

}

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

CommandLine cmd;

cmd.Parse(argc, argv);

// Create nodes

NodeContainer nodes;

nodes.Create(2);

// Configure Point-to-Point link

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

pointToPoint.SetChannelAttribute(“Delay”, StringValue(“2ms”));

NetDeviceContainer devices = pointToPoint.Install(nodes);

// Install Internet stack

InternetStackHelper stack;

stack.Install(nodes);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

// Install applications

uint16_t port = 9;

UdpEchoServerHelper server(port);

ApplicationContainer serverApp = server.Install(nodes.Get(1));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

UdpEchoClientHelper client(interfaces.GetAddress(1), port);

client.SetAttribute(“MaxPackets”, UintegerValue(100));

client.SetAttribute(“Interval”, TimeValue(MilliSeconds(100))); // Send a packet every 100 ms

client.SetAttribute(“PacketSize”, UintegerValue(1024));

ApplicationContainer clientApp = client.Install(nodes.Get(0));

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

// Install Flow Monitor

FlowMonitorHelper flowmonHelper;

Ptr<FlowMonitor> monitor = flowmonHelper.InstallAll();

// Schedule utility calculation

double simulationTime = 10.0; // seconds

Simulator::Schedule(Seconds(simulationTime), &MonitorThroughput, monitor, simulationTime);

Simulator::Run();

Simulator::Destroy();

return 0;

}

Explanation of the Script

  1. Utility Function:
    • A logarithmic utility function is leveraged: U(x)=log⁡(1+x)U(x) = \log(1 + x)U(x)=log(1+x) where xxx is the throughput in bits for each second.
  2. Flow Monitoring:
    • The FlowMonitor module monitors the packet flows and determines throughput for every flow.
  3. Aggregate Utility:
    • The UtilityCalculator class evaluates the utilities of every flow for determining the aggregate utility.
  4. Throughput Calculation:
    • Throughput is calculated as:

Throughput=Total Bytes Received×8Simulation Time\text{Throughput} = \frac{\text{Total Bytes Received} \times 8}{\text{Simulation Time}}Throughput=Simulation TimeTotal Bytes Received×8​

  1. Logging:
    • The aggregate utility and individual flow utilities are recorded.
  1. Run the Simulation
  1. Construct the script and run the simulation:

./waf –run “your-script-name”

  1. Monitor the records for individual flow utilities and the aggregate utility.
  1. Analyze Results
  • Impact of Traffic:
    • Modify the packet size or transmit interval for examining the influence over aggregate utility.
  • Fairness:
    • Launch several flows including diverse priorities and then monitor how the utility varies.

We had offered the Network Aggregate Utility implementation in a stepwise manner with sample coding using NS3 simulation environment. Also, we are equipped to provide additional insights for advanced exploration of this topic.