  A bound on the maximum information transmission rate through a cascade of
Gaussian links is presented. The network model consists of a source node
attempting to send a message drawn from a finite alphabet to a sink, through a
cascade of Additive White Gaussian Noise links each having an input power
constraint. Intermediate nodes are allowed to perform arbitrary
encoding/decoding operations, but the block length and the encoding rate are
fixed. The bound presented in this paper is fundamental and depends only on the
design parameters namely, the network size, block length, transmission rate,
and signal-to-noise ratio.
