A method for networking a small number of serial HF modems has been developed at Harris. The objective of this particular technique is to provide an extremely robust method for communicating low rate data at differing priorities over the HF band. Automated frequency selection is incorporated without requiring additional sounding equipment. A signaling scheme with capabilities similar to the one employed by Harris' serial HF modems is required by this network approach.This paper discusses a simulation of the network. The simulation runs on Harris' Concert system utilizing up to 64 parallel processors. It simulates the HF channel, modem and networking protocols as well as generation and queueing of traffic. Use of parallel processors allows the simulation to be partitioned in a fashion that closely parallels an implementable system. Emphasis will be placed on requirements for meaningful simulation of the HF channel, as a description of the network and its performance has been previously reported.'
INTRODUCTION This paper describes simulation work performed on a HarrisStressed Communication IR&D initiated during January of 1984. The goal of this task was to develop a simulation that could demonstrate and evaluate various networking techniques involving terminals equipped with Harris' serial HF modems. The network concept for this simulation was a small number of terminals in a network where the average data rate is quite low.A secondary objective of this project was to evaluate our Concert parallel processing testbed (being developed concurrently on a different IR&D project) as a simulation machine. Many characteristics of the resulting program, such as the choice of the C language, were consequences of this second objective.