How to add access packet data to encode and add extra layer of security at physical layer ?

[sam patel]

Hi all,

I am new to NS3. Can anyone please suggest me how to encode the data of the packet at the physical layer ? I want to add an extra layer of security in the network same as psuedo random code technique or something like this, basically i want to send my data from all node at the same time at single channel. Is it possible with NS3 ? 

Can anyone direct me in the right direction ? 

Thanks.