double LocationUE2d (NodeContainer ue, NodeContainer gnb)
{
cout<<"At: "<<Simulator::Now().GetSeconds()<<" Seconds"<<endl;

Vector posGNB=gnb.Get (i)->GetObject<ConstantPositionMobilityModel> ()->GetPosition();
Vector posUE=ue.Get (i)->GetObject<ConstantPositionMobilityModel> ()->GetPosition();

    double dis2;
    dis2 = sqrt( pow((posUE.x - posGNB.x), 2.0) + pow((posUE.y - posGNB.y),2.0);

return dis2;
}