[e2e] feedback mechanisms and network modelling.

[alok]

Hi,

I would like to know the following as it has been confusing me for sometime,

Lets say I was to model a "network behaviour" with some inbuilt feedback in
a model similar to lets say, a common emitter amplifier 3 pin transistor
circuit.

In such circuits, the fundamental assumption while defining the "s" domain
functions and making an input versus output plot is that "signal propogation
is immediate".

The moment i put a signal in the Base side circuit, I assume the Emitter
side would react etc. and plot the function.

My questions
1. is this based on a fundamental assumption that speed of
light/current/wavelet/whatever is inifinity? I guess yes....
2. When trying to apply similar models to networks where "distance" plays a
role, how does when consider the "time lag" for propogation in the
mathematical equations?

thanks and rgds
Alok