Lr-Wpan: Propagation models used

[josh]

Hi Tommaso,

I have a question:

1) In the example provided for LR-WPAN module, the Logdistance  propagation model does not seem to work:

if you comment the lines below in all examples you will still receive packets correctly

 

//Ptr<LogDistancePropagationLossModel> model = CreateObject<LogDistancePropagationLossModel> ();

//channel->AddPropagationLossModel (model);

This is same as setting no propagation model at all;

Could this be a bug or there is a reason for that?

Thank you 

CJ

[Tommaso Pecorella]

Hi,

if you don't provide a propagation loss model, no path loss will be added. This means that the nodes can sill receive each other, and can keep receiving no matter how far away they are.

In particular the code is here:

void

SingleModelSpectrumChannel::StartTx (Ptr<SpectrumSignalParameters> txParams)
{
  [...]

              if (m_propagationLoss)
                {
                  double propagationGainDb = m_propagationLoss->CalcRxPower (0, senderMobility, receiverMobility);
                  NS_LOG_LOGIC ("propagationGainDb = " << propagationGainDb << " dB");
                  pathLossDb -= propagationGainDb;
                }

where m_propagationLoss is a pointer to the propagation loss model.

This does not means that the LogDistancePropagationLossModel is working for sure. It only means that removing it will not mean that the nodes will not communicate.

Cheers,

T.