United States Military Academy USMA Digital Commons ACI Journal Articles Army Cyber Institute 11-6-2020 Resiliency by Retrograded Communication - the Revival of Shortwave as a Military Communication Channel Jan Kallberg Army Cyber Institute, [email protected] Stephen S. Hamilton Army Cyber Institute Follow this and additional works at: https://digitalcommons.usmalibrary.org/aci_ja Part of the Communication Commons, Computer Engineering Commons, Computer Sciences Commons, Defense and Security Studies Commons, and the Electrical and Computer Engineering Commons Recommended Citation J. Kallberg and S. S. Hamilton, "Resiliency by Retrograded Communication-the Revival of Shortwave as a Military Communication Channel," in IT Professional, vol. 22, no. 6, pp. 46-51, 1 Nov.-Dec. 2020, doi: 10.1109/MITP.2020.3029944. This Article is brought to you for free and open access by the Army Cyber Institute at USMA Digital Commons. It has been accepted for inclusion in ACI Journal Articles by an authorized administrator of USMA Digital Commons. For more information, please contact [email protected]. Resilience and Reliability Resiliency by Retrograded Communication-the Revival of Shortwave as a Military Communication Channel Jan Kallberg and Stephen S. Hamilton United States Military Academy Abstract—In the last three decades, the great powers have become increasingly dependent on satellite communication (SATCOM), very high frequency (VHF), and ultrahigh frequency providing high bandwidth line-of-sight communications. These military communication channels lack resilience because an electronic warfare (EW) campaign can affect both VHF and SATCOM simultaneously. The 1940s preferred spectrum, high frequency, with its different propagation patterns, offers an opportunity for military communication resiliency in the 21st century. The concept of retrograding could give an operational advantage and create the ability to sustain communication in EW saturated environment. & DEFENSE FORCES, COAST guard, homeland and reliant on stable communications providing security, and emergency management agencies ample bandwidth to support operations and have, during the last decades, become dependent information flow within the organization. The cur- rent deployed tactical and operational communi- cation networks are highly dependent upon line- of-sight (LOS) communication utilizing very high Digital Object Identifier 10.1109/MITP.2020.3029944 frequency (VHF), ultrahigh frequency (UHF), and Date of current version 6 November 2020. higher frequencies. The information grids are This work is licensed under a Creative Commons Published by the IEEE Computer Society IT Professional Attribution-NonCommercial-NoDerivatives 4.0 46 License. For more information, see https:// creativecommons.org/licenses/bycd/4.0/ tailored by a network of radio, datastream, radio early 1800s. The U.S. railway system in 1830 links, and satellite communication (SATCOM), all was 40 miles, and by 1860, 28,920 miles of rail- requiring a near to LOS for sufficient propagation, road been laid down.3 The telegraph lines fol- bandwidth, and transmission quality. lowed the railroads, and during the American Meanwhile, the efforts to disrupt and degrade Civil War, 1861–1865. Both sides used the tele- military communications are equally focused on graph to instruct and command units during the VHF/UHF bands that are prevailing for tacti- the engagement. cal and operational radio and data traffic. Within In comparison to landline, the earlier under- the last decade, especially Russia and China, sea cables struggled with extremely low band- have made a dedicated effort to radically width down to a word a minute, which increased improve their ability in electronic warfare (EW) over time. The great powers of the time, the and create effects in the electromagnetic spec- United Kingdom, the United States, France, Rus- trum (EMS) in the pursuit to deny or degrade tar- sia, and Germany had in the early 1900s estab- geted communication channels. Parallel with lished land-based networks of wireless telegraph this development SATCOM communication risks stations. At the outbreak of World War One, the have increased as several states developed elec- great powers of the day had outfitted their larger tromagnetic, kinetic, and cyber ability to disrupt warships with wireless telegraphs using low fre- these communications. quency, also called longwave, and medium fre- A potential future conflict with a capable quency, known as medium wave, providing near-peer adversary; Russia or China are notable communication 80–200 km between warships. in that they have heavily invested in EMS warfare Due to the size and electricity consumption of capacity, and are capable of employing EW the early wireless telegraph, the military wire- throughout their force structure.1 EW elements less equipment for armies had a limited range, deployed within theaters of operation threaten and the early airborne wireless telegraphs had to degrade, disrupt, or deny VHF, UHF, and SAT- ranges that were less than 2 km. COM communication. The introduction of shortwave in the 1920s In this scenario, high frequency (HF) radio is gave governments, companies, and individuals a viable backup mode of communication. The the ability to communicate over unprece- ability retrograde to HF, commonly referred to dented distances at a low cost.4 The innovation as shortwave, creates resilience in an EW-satu- of more efficient transmitters also made it pos- rated operational environment. The HF networks sible to design and produce mobile two-way provide satisfying bandwidth if the focus is to radio.4 During World War Two, the Korean transmit operational information, command, War, and the War in Vietnam, HF was a stan- and control. dard way of communicating that was gradually taken over by VHF during the War in Vietnam. The successful launch of Telstar5 in 1962 and HISTORICAL PATH the evolution of satellite communication during The first globally operating military force, with late 1960 changed the flow of communications.6 a presence on all continents, was the British Army In the early 1960s, HF and cable were utilized to and the Royal Navy. They were instrumental in communication to the U.S. or higher com- the growth of the British colonial possessions. mands in theater. Post-Vietnam and the early Once the British Empire was established, there 1980s, tactical VHF, radio link, and SATCOM was a need to communicate with British colonies were utilized for communication to higher com- and direct a British military presence. This paved mands. From the 1980s, this development the way for financing and incentives to rapidly cre- towards VHF/UHF LOS communications has ate a network of undersea cables that linked the accelerated. Since the early 1990s HF is rarely colonies with Great Britain in the 1850s and utilized by ground forces. Even if HF equipment 1860s.2 The telegraphy, as a form of domestic is fielded it is seldom used. However, HF con- communication, had followed the unprecedented tinues to be used for limited tasks within increase in transportation infrastructure in the navies and air forces. November/December 2020 47 Resilience and Reliability BANDWIDTH ADDICTION battlefield with clarity. Without them, many of our The vast majority of the world’s modern most important military advantages evaporate.” armies’ ability to employ HF radio systems has Even if the U.S. today is dominant in military atrophied significantly since the Cold War as satellite communication, several other countries NATO, and numerous other countries transitioned are quickly building a spaceborne information to counterinsurgency operations. An era of abun- infrastructure, where Russia, China, and India dant and close-to-uninterrupted bandwidth is com- have taken the lead. ing to an end as the future threat landscape, and The knowledge that the high-bandwidth, potential conflicts will likely involve aggressive almost always available, networks will likely be at EW, counter-SATCOM,7 and anti-satellite meas- least degraded in a future conflict should drive a ures.8 Also, satellites can be destroyed by cascad- cultural shift toward a more frugal usage of com- ing events due to debris from kinetic anti-satellite munication that reemphasizes the exchange to attacks on other spaceborne assets9 or space what is mission essential. debris already existing in orbit.10 In the past, the radiotelegraph operators, and After two decades with the uncontested spec- the organizations that utilized the Morse code, trum, the U.S. Armed Forces, and a vast majority solved the lack of bandwidth by compressing mes- of the world’s modern armies, have been used to sages. As an example, “2 GERSUB 10 NM SSW GIB” having available bandwidth, communications, transmitted in a few words reads two German sub- and the ability to switch between communication marines are sighted ten nautical miles South- channels with limited interruption and excellent South-West of Gibraltar. During WW I and WW II quality. The counter insurgency operations have trained radiotelegraphists were able to send and provided rear operational areas with a stable receive information that managed ground, air, and energy supply, enabling the ability to set up satel- naval operations over vast spaces. The notion lite and radio links, and reliable communication that current operations need megabits per second channels to higher commands, air assets, medical in available bandwidth is a sign that today’s resources, and the logistics chain. armies, coast