Configuration of LTE parameters

[Bob]

I have a few questions about these parameters shown in the tutorial. 

default ns3::LteEnbNetDevice::UlBandwidth "25"
default ns3::LteEnbNetDevice::DlBandwidth "25"
default ns3::LteEnbNetDevice::DlEarfcn "100"
default ns3::LteEnbNetDevice::UlEarfcn "18100"
default ns3::LteUePhy::TxPower "10"
default ns3::LteUePhy::NoiseFigure "9"
default ns3::LteEnbPhy::TxPower "30"
default ns3::LteEnbPhy::NoiseFigure "5"

1. what is the difference between LteEnBPhy::TxPower and cmd.AddValue ("enbTxPowerDbm", "TX power [dBm] used by HeNBs (defalut = 46.0)", enbTxPowerDbm), used in other examples?
2. are 9 and 5 typical noise figure values for eNB and UE in LTE systems(in dBm I guess?)?
3. what are DlEarfcn and UlEarfcn?
4. in lena examples, a bidirectional UDP connection is established between the UEs and a remote host, with a rate of 10 packets per seconds. Does ns3 make sure the size of the packets is such that UlBandwidth and DLBandwidth are not exceeded?

Thank you,

[Konstantinos]

Hi,

1. The difference is in the way you use the config framework.The first, I assume, uses the ConfigStore with a file being read with several parameters. The second (cmd.AddValue) uses the command line arguments to configure the TxPower. It's a matter of how you want to load your parameters.

2. I am not an expert, but that could be the case for certain scenarios.

3. From the ns-3 documentation:

• DlEarfcn: Downlink E-UTRA Absolute Radio Frequency Channel Number (EARFCN) as per 3GPP 36.101 Section 5.7.3.
  • Set with class: ns3::UintegerValue
  • Underlying type: uint16_t 0:6599
  • Initial value: 100
  • Flags: construct write read
• UlEarfcn: Uplink E-UTRA Absolute Radio Frequency Channel Number (EARFCN) as per 3GPP 36.101 Section 5.7.3.
  • Set with class: ns3::UintegerValue
  • Underlying type: uint16_t 18000:24599
  • Initial value: 18100
  • Flags: construct write read

4. The DL/ULBandwidth in LTE are number of resource blocks available. If your application is sending more traffic, then packets might be lost (in case of UDP) or a proper congestion mechanism will be used (in case of TCP). 

I would recommend to study the LTE background in order to clarify how all these parameters affect your system and what is their meaning. 

[Bob]

Thank you,

regarding ns3::LteEnbPhy::TxPower "30", since the name differ with respect to command line, is there a place where I can find all the available settings for input file and command line?

Thank you,

[Bob]

never mind my question. the names are the same, it's just a matter of namespace. 

thank you

[Fatma Boubakri]

Hi, how can i do a script for a downlink poxer control

[Konstantinos]

Hi,

Please read the NS-3 documentation regarding Power Control in LTE module 

https://www.nsnam.org/docs/models/html/lte-design.html#downlink-power-control

Regards,

K