Re: [ns] Obtaining SNR value

NS2 doesn't simulate SNR, it is based in thresholds. If the signal at the receiver is weaker than CSThresh_ the packet will be discarded at the physical layer, if the signal is weaker than RxThresh_ the packet will be marked as corrupted (error flag = 1) by the physical layer and send to the mac l

Re: [ns] RTSThreshold: disabling RTS/CTS

Mac/802_11 set RTSThreshold_ 2304 is working for me. Guillermo Hi I want to disable RTS/CTS in trace file. i set the value of RTSThreshold as 3000, but still i can see the RTS/CTS packets in trace files. my first question is how to disable RTS/CTS and second question is how can i observe RTS/

Re: [ns] why does the code below doesn't work as expected

object set bwvar .1875MB $object set bwvar 187.5kB $object set bwvar 1.5e6 Guillermo Biot >Hello, > >Did you get the answer to your reply? I'm asking because I am also experiencing the same problem with the throughput. >Please help me if you have a solution. > >Also please te

Re: [ns] setting error rate for two state error model

Yes, with your configuration you will have an average error rate of 5% but in a very particular way. During 0.95 seconds you will receive all the packets correctly and then you will have errors in all packets for 0.05seconds, then again 0.95 seconds of error-free packets and so on... I don't know

[ns] what is the meaning of "$self next"

Hi, I'm using some test scripts and I found the following code in one of them: $self next What does it mean? It is part of an instproc. There is no function called "next" in the script. Thank you. Regards, Guillermo

Re: [ns] How to setup - Random Error Generator in NS2

Hi Aleksandar, In order to generate random errors first you have to create the error model in your script and then attach it to the link or node where you want the packets to be dropped. For creating a random uniformly distributed errors you can type: #Create the error model set em [new ErrorMod

Re: [ns] how do i transfrom "Bit Error Rate" to "Packet Error Rate"

For your values the PER will be: BER = 1E-3 SIZE = 1000 * 8 PER = 1 - ( 1 - BER) ^ SIZE = 0.9996658 I highlight again that this formula can be used only when the errors are INDEPENDENT and UNIFORMLY DISTRIBUTED. This formula is specially not recommended in wireless scenarios where most of the

[ns] tracing errors in wireless scenario

Hi, I'm running wireless 802.11 simulations in ns-allinone-2.29 and I'm having some problems tracing the errors. When I insert an error model in my tcl script I cannot see any dropped packet in the resulting trace file. I inserted an uniform error model with rate 0.2 (20% of the packets should hav

[ns] no packets dropped when using incomingErrProc

Hi, I'm running wireless simulations in ns-2.29. For modeling errors I use the incomingErrProc as an option in node-config. The error model that I use is the uniform error model with a rate of 0.4, but when I check the trace file no packet is dropped. What am I doing wrong? Regards, Guillermo #

Re: [ns] Measuring physical data rate for wireless medium

There is a patch by Marco Fiore that implements the AARF algorithm, you can download it from http://www.telematica.polito.it/fiore/ AARF (Adaptive Auto Rate Fallback) is an algorithm that decides which bit rate should be used depending on the characteristics of the wireless channel. It makes its d

[ns] sequence chart of 802.11b

Hi, I'm doing simulations of wireless 802.11b links and I need to modify the code of the program, but I don't understand several parts. Is there any sequence chart of sending a packet in a 802.11b link? Thank you in advance, Guille