Changing bearers for UE -> enB in ns3?

[ryan...@gmail.com]

Hello all,

I'm trying to configure an eps bearer between my UE and enB using the code 

GbrQosInformation qos;

  qos.gbrDl = 2400;  // bit/s, considering IP, UDP, RLC, PDCP header size

  qos.gbrUl = 2400;

  qos.mbrDl = qos.gbrDl;

  qos.mbrUl = qos.gbrUl;

  enum EpsBearer::Qci q = EpsBearer::GBR_CONV_VOICE;

  EpsBearer bearer (q, qos);

  lteHelper->ActivateDedicatedEpsBearer (ueLteDevs, bearer, EpcTft::Default ());

Is there a default bearer that is used as well as this bearer?  How can I check this?  I'm using tdtbfq, but I'm not getting the results I'd expect from setting gbr&mbr to something low.  My hunch is that there is some default bearer with infinite bitrate.  Any help is appreciated :)

[Konstantinos]

Hi,

Yes, the default EPS bearer is activated when you use LteHelper::Attach() method as documented in the API, which if I'm correct is the NGBR_VIDEO_TCP_DEFAULT

void ns3::LteHelper::Attach	(	Ptr< NetDevice >	ueDevice,
		Ptr< NetDevice >	enbDevice
	)

Manual attachment of a UE device to the network via a given eNodeB.

Parameters

ueDevice	the UE device to be attached
enbDevice	the destination eNodeB device

In addition, the function also instructs the UE to immediately enter CONNECTED mode and activates the default EPS bearer.

The function can be used in both LTE-only and EPC-enabled simulations. Note that this function will disable Idle mode initial cell selection procedure.

[Biljana Bojović]

Hi Ryan,

I guess that there is some error in your script. I suggest that you enable logging of TdTbfqFfMacScheduler scheduler. And I think it could help you taking a look into lte/test/lte-test-tdtbfq-ff-mac-scheduler.cc test suite. You can see there various configurations of gbr and mbr, and how the dedicated bearer is being activated.

Cheers,
Biljana

[younes ben khalfallah]

Bijana Bojovic can you help me to activate the dedicated bearer please

[Qi Wang]

Hello, I am a postgraduate student. I got the same question as you. Have you solved this problem? I would appreciate it if you could help me.