Finding distance between two nodes using using unetstack with groovy script

Question

I am implementing a routing protocol for underwater communication networks based on the distance between neighboring nodes. I created an agent and written a script to find the distance between neighboring node using a ranging agent but I am getting an error

No such property: ranging for class:.

I will attach scripts I wrote.

1. 3-node-network_test.groovy : It is a simulation script in which I deployed 3 nodes. Node 1 is the sink node, in which ranging agent and sink script will be executed. Node 2 and 3 are running "ranging agent" and "node_agent".
2. sink.groovy: Will initialize the beaconing process by broadcasting a beacon.
3. node_agent: Which receives a beacon from the sink and identify the distance to sink. Here I have written script to find the distance to sink using:

---

complete script. how to find distance in unetstack?

3-node-network_test.groovy:

//! Simulation: Simple 3-node network
import org.arl.fjage.*


// run the simulation forever
simulate {
  node '1', remote: 1101, address: 1, location: [ 0.km, 0.km, -15.m], shell: true, stack: {container ->
    container.add 'ranging', new org.arl.unet.phy.Ranging()   
    container.shell.addInitrc "${script.parent}/sink.groovy"
  }
  node '2', remote: 1102, address: 2, location: [ 1.km, 0.km, -15.m], shell: 5102, stack: {container ->
    container.add 'ranging', new org.arl.unet.phy.Ranging();
    //container.shell.addInitrc "${script.parent}/sink.groovy"
    container.add 'node_agent', new node_agent();
  }
  node '3', remote: 1103, address: 3, location: [-1.km, 0.km, -15.m], shell: 5103, stack: { container ->
    container.add 'ranging', new org.arl.unet.phy.Ranging()
    container.add 'node_agent', new node_agent();    
  }
}

Sink.groovy:

import org.arl.unet.*
import org.arl.unet.phy.*
import org.arl.unet.mac.*
//import org.arl.unet.nodeinfo.NodeInfo
import org.arl.unet.PDU 
import org.arl.fjage.*
import static org.arl.unet.Services.*
import static org.arl.unet.phy.Physical.*
import org.arl.unet.phy.Ranging.*


int hc = 0, ad;
float neighbor_dist;
float rang

subscribe phy;
send = { count = 1 ->

    println ''' BROADCASTING '''
    count.times {

          phy << new DatagramReq(to: Address.BROADCAST, protocol: Protocol.MAC, data: [node.address, hc, 0]);

        }

}

node_agent.groovy:

import org.arl.fjage.Message
import org.arl.unet.*
import org.arl.unet.net.Router
import org.arl.unet.phy.*
import org.arl.unet.mac.*
import org.arl.fjage.RealTimePlatform
import org.arl.unet.nodeinfo.NodeInfo
import org.arl.fjage.*
import org.arl.unet.phy.Ranging.*
import org.arl.unet.phy.RangeNtf.*
import org.arl.unet.phy.RangeReq 


class node_agent extends UnetAgent {
  int neighbor, addr;
    float neighbor_distance;

    void startup() 
    {

      def phy = agentForService Services.PHYSICAL;
      subscribe topic(phy);

      def rang = agentForService Services.RANGING;
      subscribe topic(rang);

      def nodeInfo = agentForService Services.NODE_INFO;
      addr = nodeInfo.address;

    }

    void processMessage(Message msg) {

    if (msg instanceof DatagramNtf && msg.protocol == Protocol.MAC)
    {     
      neighbor = msg.from;
      println " BEACON RECEIVED FROM:" +neighbor
      ranging<< new RangeReq(to: neighbor);   

      }

    else if (msg instanceof RangeNtf )
    {   

        float neighbor_distance = msg.getRange();
        println " Distance between node "+addr + " and neighbor" +neighbor+ "is" + neighbor_dis

    }  // End of if*/
    else {

    }
   }  //End of process message
}

Answer 1

The RangeReq needs to be sent to the ranging agent. You can get the agent using agentForService Services.RANGING. Since you're looking it up in the startup() anyway, you can store it in an attribute and use it later to request range. Something like:

def ranging

void startup() 
{
         :
      ranging = agentForService Services.RANGING;
         :
}

void processMessage(Message msg)
{
      if (msg instanceof DatagramNtf && msg.protocol == Protocol.MAC)
      {     
        neighbor = msg.from;
        println " BEACON RECEIVED FROM:" +neighbor
        ranging << new RangeReq(to: neighbor);
      }
      else if (msg instanceof RangeNtf )
      {   
        float neighbor_distance = msg.getRange();
           :
     }
   }
}