The operational use of an automated high frequency radio system incorporating automatic link establishment and single-tone serial modem technology for U.S. Navy ship-shore communications

The US Navy has all but ceased to use high frequency (HF) radio for long-haul ship-shore communications. Satellite systems have rightfully assumed this role, but the antiquated nature of the Navy HF system has soured planners on even considering HF for supplementary uses or other roles. In an attempt to dispel this undeserved reputation and gain operating experience for application of automation to new shipboard HF systems, an HF radio communications system incorporating automatic link establishment (ALE), single-tone serial modems and 500-watt transceivers was deployed on USS TARAWA (LHA-1) and to serving Navy shore communications stations during her recent deployment to the Indian Ocean and Persian Gulf. The authors describe the use of this system for bidirectional 600 baud message traffic. This is the first application of the combination of MIL-STD-188-141A ALE and MIL-STD-188-100A single tone serial modem technology in a US Navy operational environment. The ALE radio system was used to automatically test and select the best channel from among several assigned frequencies and establish a link between ship and shore. Accumulated message traffic was then passed over the single-tone serial modem to the distant end. Technical details of the installation and operational techniques are presented along with a discussion of how automation greatly reduced the level of skill and experience needed to successfully operate this HF system. Test results are presented which illustrate the success enjoyed in maintaining communications over paths which had long been considered unworkable with existing shipboard HF equipment and techniques. The potential for application of automated HF to short-range over-the-horizon (OTH) communication needs for littoral warfare is also discussed.<>