[ns] Help: Simulation of FEC

[Ankit Agarwal]

Hi Everyone,

I am new to NS-2 and am trying to simulate Forward
Error Correction (FEC) in my experiments in NS2 (I am
simulating wireless mobile ad hoc networks).

I wish to use the following technique for FEC:

At the source, for every 3 packets of data generated,
I want to have 2 redundant data packets also
generated. Thus a total of 5 packets are generated for
every 3 packets of real data.

If the receiver receives any 3 of these 5 packets,
then it will be assumed that the 3 original packets of
data have been received. I believe that this is a
standard (5, 3) Reed-Solomon encoding.

I am using a CBR traffic source to generate 160 byte
packets every 20 miliseconds (PCM encoded speech). Can
anyone give me an idea of how to generate the 2 extra
packets and push them into the same stream so as not
to mess up the original flow?

If the scenario with a CBR source cannot be modified.
Can someone give me an idea of how I can simulate this
FEC in NS2?

Another idea that I have is to simply generate five
160 byte packets in the same time that it should take
to generate the 3. Would this be correct to simulate?

Any help or guidance would be greatly appreciated.

Thanks,
Ankit.


=====
"Tough times do not last, only tough people do."
"A ship in the harbor is safe...but thats not what ships were made for."
"Do, or do not. There is no try." (Yoda)
Ankit Agarwal
5000 Oak Street, #815, Kansas City, MO 64112.
Telephone: (816) 531-4186. Email: ankit_agarwal@yahoo.com

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