Hi Mike,
I was able to install the communications package after following the instructions, given in the link. In short, I downloaded the Octave3.6.4_gcc4.6.2_pkgs_20130402.7z file and unzipped it into the respective folders (installation directory). Used the commands below.
pkg rebuild -auto
pkg rebuild -noauto ad % may crash octave when loaded and 'clear all' is executed
pkg rebuild -noauto nan % shadows many statistics functions
pkg rebuild -noauto gsl % shadows some core functions
pkg rebuild -auto java
Thank you.
Shivaprasad.