如何在SimuLTE与Veins中启用SUMO TraCI并获取实时交通数据？

Hey there! Let me break down exactly how to make this work for your SimuLTE + Veins setup—since you’re already familiar with pure Veins, this will feel familiar with just a few extra steps for LTE integration.

In the combined SimuLTE + Veins simulation, Veins handles traffic mobility and TraCI interactions, while SimuLTE manages LTE communication. The key is to fetch real-time traffic data via TraCI in your Veins node's application layer, then pass that data to SimuLTE's LTE stack to send as safety messages.

1. Pick the Right Code Location #

Just like in pure Veins, you’ll work within the application layer module of your Veins node (usually attached to a node with the TraCIMobility module, like VeinsVehicle). This is where you’ll add TraCI logic and handle data handoff to SimuLTE.

2. Use TraCICommandInterface to Grab Real-Time Data #

First, get a reference to the TraCIMobility module and its associated TraCI interface in your application's .cc file:

// Fetch the TraCIMobility module from the parent node
TraCIMobility* mobility = dynamic_cast<TraCIMobility*>(getModuleByPath("^.mobility"));
if (!mobility) {
    error("Failed to locate TraCIMobility module");
}
// Access the TraCI command interface
TraCICommandInterface* traci = mobility->getCommandInterface();

Example 1: Get Average Speed for the Current Road #

If you need the average speed of vehicles on the road your car is currently on:

// Get the ID of the road your vehicle is traveling on
std::string currentRoad = traci->vehicle(getParentModule()->getFullName())->getRoadId();
// Fetch the average speed (in m/s) for that road
double roadAvgSpeed = traci->road(currentRoad)->getAverageSpeed();

Example 2: Calculate Overall Fleet Average Speed #

If you need the average speed of all connected vehicles in the simulation:

double totalSpeed = 0.0;
int vehicleCount = 0;
// Iterate over all vehicles in the simulation
for (const auto& vehId : traci->getVehicleIds()) {
    TraCICommandInterface::Vehicle* vehicle = traci->vehicle(vehId);
    totalSpeed += vehicle->getSpeed();
    vehicleCount++;
}
double fleetAvgSpeed = vehicleCount > 0 ? totalSpeed / vehicleCount : 0.0;

3. Pass Data to SimuLTE for LTE Transmission #

Once you have your traffic data, package it into a custom message (e.g., SafetyMessage) and send it through SimuLTE's LTE stack. Make sure your node's NED file connects the application layer to the LTE NIC's upper layer interface:

// Create your custom safety message
SafetyMessage* safetyMsg = new SafetyMessage();
safetyMsg->setAvgSpeed(roadAvgSpeed); // Populate with your data
safetyMsg->setSenderId(getParentModule()->getId());

// Fetch the SimuLTE LTE NIC module
LteNic* lteNic = dynamic_cast<LteNic*>(getParentModule()->getSubmodule("nic"));
if (lteNic) {
    // Send the message to the LTE stack for transmission
    send(safetyMsg, "upperLayerOut");
}

Note: Double-check your NED file to ensure the application's upperLayerOut gate links to the LTE NIC's upperLayerIn gate.

4. Test & Debug #

• Start by validating TraCI data fetching in a pure Veins setup first—use OMNeT++'s EV logging to confirm data is correct:

  EV_INFO << "Current road average speed: " << roadAvgSpeed << " m/s\n";
  

• Then test the full SimuLTE + Veins setup to ensure messages are transmitted and received over LTE.
• For real-time updates, set up a timer (e.g., every 100ms) to periodically fetch data and send messages—avoid blocking the simulation loop with continuous TraCI calls.

• Make sure your Veins and SimuLTE versions are compatible, and your launch script (like run.sh) correctly configures paths for both frameworks.
• Always call TraCI methods within the simulation event loop (e.g., in handleMessage or a scheduled timer event) to avoid disrupting simulation timing.

内容的提问来源于stack exchange，提问作者J.G