To implement mobile computing in ns-3, we have to simulate a network with mobile nodes. The mobile nodes should communicate over a wireless network. By using this simulation, we can incorporate various types of communication protocols which includes Wi-Fi, LTE, or other mobile communication standards that fully depends on your specific requirements. Let’s dive into the steps for setting up a basic mobile computing simulation in ns-3 using Wi-Fi. All areas of mobile computing in ns-3 with good simulation support are aided by our team.
Steps to implement mobile computing in ns-3
- Set up your development environment
- Install ns-3 : Ensure that you have ns-3 installed in your computer. To install, follow the official ns-3 installation guide.
- Install required modules : Make sure that you have installed all the required ns-3 modules which includes Internet, mobility and Wi-Fi modules.
- Create a basic Wi-Fi simulation script
Here is a basic mobile computing scenario setup sample script using ns-3 features :
#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;
NS_LOG_COMPONENT_DEFINE(“MobileComputingExample”);
int main(int argc, char *argv[])
{
// Set simulation parameters
uint32_t numNodes = 5;
double simTime = 20.0; // Simulation time in seconds
double nodeSpeed = 20.0; // Speed of nodes in m/s
CommandLine cmd;
cmd.AddValue(“numNodes”, “Number of nodes”, numNodes);
cmd.AddValue(“simTime”, “Simulation time”, simTime);
cmd.AddValue(“nodeSpeed”, “Speed of nodes”, nodeSpeed);
cmd.Parse(argc, argv);
// Create nodes
NodeContainer nodes;
nodes.Create(numNodes);
// Set up WiFi
WifiHelper wifi;
wifi.SetStandard(WIFI_PHY_STANDARD_80211n_5GHZ);
YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default();
YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();
wifiPhy.SetChannel(wifiChannel.Create());
WifiMacHelper wifiMac;
wifiMac.SetType(“ns3::AdhocWifiMac”);
NetDeviceContainer devices = wifi.Install(wifiPhy, wifiMac, nodes);
// Install the Internet stack on nodes
InternetStackHelper internet;
internet.Install(nodes);
// Assign IP addresses to devices
Ipv4AddressHelper ipv4;
ipv4.SetBase(“10.1.1.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces = ipv4.Assign(devices);
// Set up mobility
MobilityHelper mobility;
mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,
“MinX”, DoubleValue(0.0),
“MinY”, DoubleValue(0.0),
“DeltaX”, DoubleValue(5.0),
“DeltaY”, DoubleValue(10.0),
“GridWidth”, UintegerValue(3),
“LayoutType”, StringValue(“RowFirst”));
mobility.SetMobilityModel(“ns3::ConstantVelocityMobilityModel”);
mobility.Install(nodes);
for (uint32_t i = 0; i < nodes.GetN(); ++i) {
Ptr<ConstantVelocityMobilityModel> mobilityModel = nodes.Get(i)->GetObject<ConstantVelocityMobilityModel>();
mobilityModel->SetVelocity(Vector(nodeSpeed, 0, 0));
}
// Install applications
uint16_t port = 9;
UdpEchoServerHelper echoServer(port);
ApplicationContainer serverApps = echoServer.Install(nodes.Get(0));
serverApps.Start(Seconds(1.0));
serverApps.Stop(Seconds(simTime));
UdpEchoClientHelper echoClient(interfaces.GetAddress(0), port);
echoClient.SetAttribute(“MaxPackets”, UintegerValue(320));
echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));
echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));
ApplicationContainer clientApps;
for (uint32_t i = 1; i < nodes.GetN(); ++i) {
clientApps.Add(echoClient.Install(nodes.Get(i)));
}
clientApps.Start(Seconds(2.0));
clientApps.Stop(Seconds(simTime));
// Enable tracing
wifiPhy.EnablePcap(“mobile-computing”, devices);
// Run the simulation
Simulator::Stop(Seconds(simTime));
Simulator::Run();
Simulator::Destroy();
return 0;
}
Explanation of the script
In this set up, we had created a network with VLANs to segment traffic within the network using ns-3 features. Let’s have a detailed explanation on the script below:
- Include necessary headers : Include all the required headers for ns-3 core, network, internet, Wi-Fi, mobility and application modules.
- Set simulation Parameters : Define the number of nodes and also define the simulation time and speed of the nodes.
- Create nodes : Using NodeContainer, create nodes.
- Set up Wi-Fi : Using YansWifiChannelHelper and YansWifiPhyHelper configure the Wi-Fi channel and physical layer and WifiMacHelper for ad-hoc communication.
- Set Up Mobility : Using MobilityHelper, define the positions and mobility models. In this case, ConstantVelocityMobilityModel is used to simulate nodes moving at a constant speed.
- Install internet stack : Using InternetStackHelper, install the internet stack on all the nodes.
- Assign IP addresses : Using Ipv4AddressHelper, assign IP addresses to the devices.
- Install applications : On the first node, install the UDP echo server and on the remaining nodes, install the UDP echo clients to simulate communications.
- Enable tracking : Capture packet traces using pcap tracing for analysis.
- Run the simulator : Define the simulation stopping time and run the simulator and cleanup using Simulator::Stop, Simulator::Run, and Simulator::Destroy.
Future enhancements
In future, we would like to enhance the mobility models, change the Wi-Fi standards, implement QoS etc.
- Advanced Mobility Models:
- Mobile node should include more realistic mobility models like random waypoint or models based on real-world movement patterns.
- Data Collection and Aggregation:
- To handle data in a efficient manner from multiple mobile devices, implement data collection and aggregation techniques.
- Routing Protocols:
- create and evaluate different routing protocols that suits mobile ad-hoc networks, like AODV, DSDV, or OLSR.
- Quality of Service (QoS):
- Prioritize traffic by implementing QoS mechanisms and also ensure timely delivery.
- Network Performance Metrics:
- Collect and analyze performance metrics such as throughput, latency, packet delivery ratio, and resource utilization.
- Interference Modeling :
- Model interference from ambient light and other sources and evaluate it creates a great impact on network performance.
- Fault Tolerance and Resilience:
- Implement and evaluate fault tolerance mechanisms and resilience strategies for mobile computing.
Overall, we had successfully implemented Mobile Computing in ns-3 by a setting up a basic mobile computing simulation using ns-3 features. Also, we provide more simulation support on Mobile Computing.