SINR values remain the same throughout the whole simulation LTE

[Maiden_Maiden]

Hello, I am having a bit of trouble when understanding SINR values for the UE in an LTE simulation.

My topolgy looks like this:

UE1 ------------------------ UE2 -------------------------eNB

I have installed a UDP application on all 3 nodes. I start the UE1 apps immediately, and the UE2 apps after 5 seconds. From the Flowmonitor I can see that some packets are getting dropped, but the SINR values remain completely the same.

To get the SINR values for the UE, I used this Trace:
 Config::Connect ("/NodeList/*/DeviceList/*/$ns3::LteNetDevice/$ns3::LteUeNetDevice/ComponentCarrierMapUe/*/LteUePhy/ReportCurrentCellRsrpSinr", MakeCallback (&SINR));

I also tried getting the SINR values like it was done in the LTE tests:

Ptr<LtePhy> ue1Phy = ueDevs.Get(0)->GetObject<LteUeNetDevice>()->GetPhy()->GetObject<LtePhy>();
    Ptr<LteChunkProcessor> testDlSinr1 = Create<LteChunkProcessor>();
    LteSpectrumValueCatcher dlSinr1Catcher;
    testDlSinr1->AddCallback(MakeCallback(&LteSpectrumValueCatcher::ReportValue, &dlSinr1Catcher));
    ue1Phy->GetDownlinkSpectrumPhy()->AddDataSinrChunkProcessor(testDlSinr1);

I have enabled a pathloss propagation for LTE and also enabled all traces, but still the values of SINR don't change at all. Could you give me an idea what the reason for that might be?

Thanks in advance!

[Tommaso Pecorella]

The SINR does change if:

- You move the nodes

- There is some interference (in terms of collisions, which you probably don't have)

- The path loss model contains a random part (e.g., fading).

If none of the above applies, then the SINR will be always the same.

[Maiden_Maiden]

Hello Tommaso,

Thank you very much for your reply. I also tried to cause maybe some interference by increasing the TxPower of the UE2, to be more than UE1, but still the SINR remains the same. Does the TxPower have to do with causing interference, and if yes, how could I do that?

Thanks in advance

[Tommaso Pecorella]

It's LTE, not WiFi... UEs do not generate interference between each other if they're attached to the same cell.

My best suggestion is to double check the standard before running after white rabbits.