LTE CONNECTION_SETUP error

[Gooner 내려왔다]

Hi all,
  I am getting below error, when simulated for LTE systems
"msg="method unexpected in state CONNECTION_SETUP", file=../src/lte/model/lte-enb-rrc.cc, line=847"

Anyone know about what this error is?

Note: I am connecting 2 LTE system back to back (ie UE of first system is connected to PGW of second system by p2p). Here some change is done in the constructor of point-point-EPC-helper.cc and .h, to avoid collision of IPs.

Regards,
G4L

[Gooner 내려왔다]

Hi All,
Below is the scenario I am trying to simulate

RH --> PGW1 -->eNB1-->UE1-->pgw2 -->eNB2---->UE2
I want to establish data connection between RH and UE2 through LTE1 systems.

I have modified constructor of "point-to-point-epc-helper.cc" to facilitate user input IP address for PGW, eNB and UE. Else while declaring second LTE system, duplication IP address will be shown.
But after running the scenario, I am getting below error, which happens during simulator RUN

"msg="method unexpected in state CONNECTION_SETUP", file=../src/lte/model/lte-enb-

rrc.cc, line=847"

Can someone help me in understanding what this error is?

[Gooner 내려왔다]

Hello,
The error is happening when the second UE (ie UE2) is connected to eNB2. (If this connection is removed, this problem is not happening)

So I tried using explicit way of adding "AddBearer" separately for both connections(between UE and eNB), with different traffic. But the same problem is coming. 
But the problem still persists. Can some one please help. Please someone tell me why this error is happening...




The code is like below

  //For ActivatedDedicatedEpsBearer1
        enum EpsBearer::Qci q1 = EpsBearer::GBR_CONV_VOICE;
        EpsBearer bearer1 (q1);
  // Attach one UE per eNodeB
  for (uint16_t i = 0; i < numberOfNodes; i++)
      {
        lteHelper1->Attach (ueLteDevs1.Get(i), enbLteDevs1.Get(i));
        //EPS bearer
        lteHelper1->ActivateDedicatedEpsBearer (ueLteDevs1.Get(i), bearer1,  EpcTft::Default ());
       }

  //ActivatedDedicatedEpsBearer2
  enum EpsBearer::Qci q2 = EpsBearer::NGBR_VIDEO_TCP_OPERATOR;
         EpsBearer bearer2 (q2);
  for (uint16_t i = 0; i < numberOfNodes; i++)
      {
        lteHelper2->Attach (ueLteDevs2.Get(i), enbLteDevs2.Get(i));

        //EPS bearer
        lteHelper2->ActivateDedicatedEpsBearer (ueLteDevs2.Get(i), bearer2,  EpcTft::Default ());

      }



Is there anyone else to be changed?

[Gooner 내려왔다]

The LteEnbRrc log is attached here.

Someone please let me know why this problem is happening like this. What is that I have to modify while connecting eNB2 and UE2?

Thanks,
G4L

[Zoraze Ali]

Hi Gooner,

Could you please share your script?

Kind regards,
Zoraze

[Gooner 내려왔다]

Hello Zoraze,
   Please find the script attached

Regards,
G4L

[Zoraze Ali]

Hi,

I have never tried this but i will try to help as much as i can. So, just for the check, did you try to simulate a simple epc scenario with your modified constructor? For example, just create 1 eNB, 1 UE and the EPC.

Kind regards,
Zoraze

[Gooner 내려왔다]

Hi Zoraze,
Yeah, I tried the simple EPC scenarios and they are good. Problem happens only when I tried to add a second EPC(ie EPC2, specifically when I connect eNB2 and UE2)


PFA the modified "point-to-point-epc-helper.cc", where I just parameterised the constructor. I have not not all any big modifications out there.

Regards,
G4L

[Zoraze Ali]

Hi Gooner,

I understand that you have not change many things and perhaps this is the problem. To simulate your scenario i think LTE module should be extended more. I assume that you are already familiar with the old threads around this topic. For example, the following two,

https://groups.google.com/forum/#!searchin/ns-3-users/two$20epc$20helpers/ns-3-users/_270CI0p5eg/fCg9w9FH_sQJ

https://groups.google.com/forum/#!searchin/ns-3-users/two$20epc$20helper/ns-3-users/oGRLBCR-ouY/p4cdTzGuxxAJ

You could dig in more into the code but i think it also require you to read the documentation more thoroughly to introduce this functionality. For the assert you are having, it is clear that the function which is giving the assert was not expecting the UE state to be in CONNECTION_SETUP.

Sorry, for the moment i could only help this much.

Kind regards,
Zoraze

[Gooner 내려왔다]

Hi All,
  Problem is solved by assigning separate cellId to the second LTEhelper instance, by means of LTE_Helper constructor. By default 0 was assigned to them

Thanks

[Zoraze Ali]

Hi Gooner,

Sorry for the late reply. You mean by assigning a different cell id, the scenario you defined in your first post is now simulating without any errors?

Kind regards,
Zoraze

[Gooner 내려왔다]

yes Zoraze, it works fine if a different cellId is assigned to the second LTEhelper instance.

Regards,
G