Meeting military requirements for increased data rates at HF

Military operational requirements for data bandwidths are increasingly demanding rates which exceed the capacity of traditional HF circuits. New waveform standards, Mil-Std 188-110B and STANAG 4539, alleviate the problem to some degree by increasing user data rates from 2400 bps to 9600 bps. However, these rates still fall far short of the rates obtained with other media, with the result that HF is open not considered for use as a primary communications bearer. Often HF is not even considered in a secondary capacity and is used only as a communications medium of last resort. Increasing HF data rates to 64 kbps or beyond using multiple channels in the manner proposed in this paper, would dramatically widen the applications for which HF could be considered as a primary mode of communications.