HF combat net radio lesson learned again

HF combat net radio lesson learned again

David M. Fiedler

Recently, at the 2003 Signal Symposium and prior to that in his testimony to the Congress, LTG William “Scott” Wallace, former commanding general of V Corps during the invasion of Iraq, made the following statement about the command, control and communications situation during the Iraq fight. “Despite the introduction of battle-command-on-the-move capabilities that I enjoyed in my assault command post, the vast majority of tactical leaders and CPs (command posts) enjoyed few on-the-move capabilities. Most were tethered to a CP and largely dependant upon line-of-sight communications.

“Case in point. At the corps level the G2 could see individual fighting positions defending a critical bridge because we had a UAV (unmanned-aerial vehicle) leading the lead formations. But we could not get the data down to the unit who was taking the objective because all the CPs were moving. It was a deliberate attack at the corps level, but a movement to contact at the battalion level,” Wallace said.

This statement upsets me greatly both as a student of military art, science and history; and as a Signal professional with over 35 years service in all components of the U.S. Army. Wallace’s statement when reasonably analyzed can only lead to the conclusion there was a failure in both communications planning and communications execution. The means to provide what Wallace needed (beyond-line-of-sight-on-the-move communications) certainly exist today in our widely deployed family of high-frequency combat net radios and has for many generations. Why then were we not able to improvise, and adapt our existing resources to overcome Wallace’s communications problems?

Wallace and the whole Coalition Force in Iraq were magnificently executing classic offensive “Blitzkrieg” operations. In German, Blitzkrieg means lightning war. In the modern tactical sense it includes attacks where the enemy thinks you cannot attack, rapid advances into the heart of enemy forces and territory, and coordinated massive air and artillery attacks that with today’s technology also includes missiles, attack helicopters and precision guided weapons. The use of such tactics is intended to stun the enemy and shock them to the point that they can no longer react. The German Army in World War II won most of their great victories with this tactic. Field Marshall’s Hans von Seekt, Irwin Rommel and Heinz Guderian (a signal branch officer), are all given credit for inventing and perfecting the Blitzkrieg tactic with military scholars giving the lions share of the credit to Guderian the signalman. Guderian was not only Germany’s premier tactician, he eventually became Chief of Staff of the army imagine that happening to a U.S. Signal officer!

Why Guderian from the signal branch? Because, not only was old Heinz a tactical genius who conceived a new combined arms organization to execute the Blitzkrieg concept (the Panzer Division/Corps/ Army) but also in his own words circa 1920: “I realized that I would no longer command from the rear with a telephone (World War I style) but from the front with a radio”. Because of Guderian’s signal background and position in the high command, he assured that each tank, aircraft, and unit command post in the Panzer force had long-range, mobile, combat-net radio communications of the right type to support its mission. (See Figs. 1 and 2). The same type radio Wallace needed almost 70 years later.


These were in large part the FuG-10 HF operating in the HF 2-18 MHz frequency range. The Guderian designed HF radio nets provided a level of command and control never before achieved on the battlefield. Long-range (HF) Combat-Net Radio made the Panzer Division and its air support the most destructive and efficient combined arms force in history. The U.S. Army learned much from the Germans of the 1930s and 1940s and thanks to officers such as Fox Connor, Ben Lear, George Marshall, Dwight Eisenhower and the always revered George Patton, the U.S. Army could also combine command and control, logistics, firepower and air support and by 1944 could out Blitzkrieg the inventors of the whole idea. We continue to improve this capability to this day as our victories in Iraq prove.

The basic concept of the German combined arms Panzer force refined by the American Army over the last 70 years and given modern technology was the force that Wallace entered Iraq with in 2003. In terms of organization and tactics. Rommel and Guderian would have felt quite at home in V Corps with their rapid movements, ability to see the battlefield, and elaborate methods of command, control and communications between ground and air elements. What would have shocked them all but particularly Guderian with his emphasis on communications, would have been the combat communications failure at the key defended highway bridge that Wallace described, and V Corps’ apparent inability to provide timely command, control and intelligence information to its forward elements with the resources it already had. The problem of reaching the battalion Wallace refers to as being unreachable and therefore conducting a movement to contact not a deliberate attack because “all the command posts were moving” is a problem that was solved well before to 1939 in both the German and U.S. armies.

Not only was it solved, it was solved without the use of satellite communications, complex tactical data networks, unmanned aerial vehicles, balloons, retransmission stations etc. A simple single-channel HF radio with the proper antenna, frequency assignment and the knowledge to use it is all that was required both then and now.

By the time the Germans invaded Poland (1939) Guderian had long worked out the techniques of Near Vertical Incidence Sky-wave HF radio communications and how to use FuG-10 HF radios, both monopole and loop antennas, surface wave radio propagation and the reflective properties of the ionosphere (NVIS) to communicate over huge areas when halted, on-the-move, or in the air. (See Fig. 3). Near Vertical Incidence Sky-wave techniques are described in U.S. Army Signal Corps publications as far back as the 1930s and are still currently reflected in our doctrine (FM24-18, FM11-53, FM11-64, FM11-65, TM11-666, MIL-HDBK-413, to name a few). Moreover, ground and airborne HF radio both fixed and on-the-move using NVIS techniques has been a topic of discussion by several authors in the Army Communicator more than a dozen times since 1983 alone.


Additionally, Special Operations Forces, Army Aviation and the Army Medical Department have deployed hundreds of new AN/ ARC-220 and AN/PRC-138/150 HF radios for exactly this purpose over the last 15 years. C3 elements of the “big” Army also possess large numbers of HF radio’s that range from the most modern (AN/PRC-150 family) to somewhat obsolete but still useable (AN/PRC-104 family) but as this instance proves, have not employed them nearly as well. This forces us to raise the question “why were minimum essential doctrinally required HF communications not available to V Corps Headquarters when they needed them in 2003 like they were for Rommel and Guderian in 1939 and for Patton and Eisenhower in the great Louisiana Maneuvers of 1940?”

Further, it also forces us to ask the question why is the U.S. Army with certain notable exceptions (SOF, AMEDD, Army Aviation) the only army in the world and the only department in the U.S. Department of Defense with the mindset to reject a proven viable, inexpensive, means of LOS and BLOS fixed and OTM military communications?

A large part of the answer is that HF communications is the victim of numerous “communications failure myths” created over the years by Signal officers desperately searching for reasons for failure to tell their commanders because they failed to be taught or to learn enough radio technology to effectively use the proven military potential of the HF medium and the equipment they were given. In short, you have to know something about HF to use it. This bad reputation was made even worse in the 1970s when it was coupled with the need to find “bill payers” for other programs such as satellite communications so HF resources were cut for both procurement and training. Additionally, during the same timeframe, Signal Corps leadership was bent on washing its hands of all combat net radio systems by declaring them “user-owned and operated”. One can only wonder at the politics behind this decision. Let’s begin to analyze Wallace’s problem by debunking some of the worst common myths about HF tactical communications:

Myth 1–The HF spectrum (2-30Mhz) by international treaty is limited to analog voice single sideband AM modulation in 3Khz channels and therefore can only support digital voice and data at rates no faster than 2400 bps.

–False; slow speed digital voice modes are in most modern HF radios for operation over degraded channels but so are MODEMS that can operate at speeds up to 9.6Kbs inside the mandated 3Khz channels. This allows voice, and digital applications such as e-mail, and imagery to be viable HF modes of operation.

Myth 2–HF radios are not good for short distance tactical communications beyond-line-of-sight and leave gaps in area coverage.

–False, while intercontinental communications distances are commonly achieved using some HF techniques, use of properly selected antennas and frequencies will produce antenna patterns good for communications over Corps and below size areas independent of the intervening terrain and without gaps in coverage. ONLY HF RADIO CAN DO THIS WITHOUT THE NEED FOR SATCOM OR UAV SUPPORT! See fig 3.

Myth 3-HF radio systems are not omni-directional and are therefore not suited for tactical communications.

–False, common HF antennas like vertical monopoles (whips), horizontal wire dipoles, and loop antennas all provide omni-directional communications when configured properly for that purpose. Even a horizontal wire dipole when located close to the earth is an omni-directional antenna (see Fig 3). These antennas can be made directional but only when elevated to a considerable height.

Myth 4–HF radio systems are more adversely affected by ionospheric storms, solar flares, sudden Ionospheric disturbances and polar blackouts.

–False to a large degree. These naturally occurring phenomena to some degree affect all radio systems. The lower portion of the HF band will be affected first. Affects range from almost nothing to complete blackout. Most modern HF systems employed by the Army have a feature called Automatic Link Establishment. This feature scans the radio’s assigned frequency band and will automatically establish communications on any authorized workable frequency quickly after a disturbance subsides. Tactical radios operating in other bands and equally affected by these factors don’t have these features and may take longer to recover.

Myth 5–“Sunspots” kill HF radio systems.

–False to a large degree. Sunspots are whirling masses of electrically charged gas formed by magnetic fields deep within the Sun. Magnetic fields often more powerful than the magnetic field of the Earth occur at the center of a sunspot. Huge waves of energy produced by the Sun’s core erupt through the surface launching a mass of electrified gas and other material. Viewed from Earth this looks like a dark spot on the surface of the Sun where the eruption occurred. The electrified gas has a large magnetic field at its surface that races through space and can disrupt radio communications and electrical systems here on Earth. These disruptions can last a while and affect all radio communications. The lower frequencies such as HF take a while to recover from such disturbances. ALE again will find channels suitable for communications and restore service faster than systems using other tactical radio frequencies. Sunspots don’t happen that often but this complex sounding phenomenon has been used to explain signal outages to commanders far beyond what is justified.

Myth 6–Levels of manmade, atmospheric, cosmic and internal electrical noise are greater in the HF frequency range and cannot be compensated for.

–False, The combination of ALE that selects the best authorized channel based on the best signal-to-noise ratio, higher transmitter power, and the system gain derived from the use of powerful voice and data digital signal processing techniques including Mixed Excitation Linear Predictive coding allow HF communications to proceed in an extremely degraded environment. Some techniques internal to modern army HF radios such as MELP will actually recover signals from near or below the noise level.

Myth 7–BLOS HF communications OTM don’t work.

–False, like everything else in radio system engineering success in OTM/BLOS HF communications depends on the critical selection of antennas and frequency. Vehicle mounted vertical monopole (whip) antennas work and will produce “surface-wave signals”. Surface wave signals will propagate out to a certain distance along the earth and then due to their contact with the earth become to weak for use in tactical communications. Depending upon the type of ground or water under the signals, signals at HF frequencies can go relatively short distances to the horizon or in the case of seawater and certain ground conditions tend to bend along the surface of the earth and travel well beyond line of sight. Signals designed to take advantage of ionospheric reflection by using mobile antennas that produce high angle energy (loops and bent over whips) will commonly cover Army Corps/ Theater size areas of operations without gaps in coverage. Only signals in the HF frequency band can be used since the ionosphere will not reflect signals at higher frequencies. While the U.S. Army has yet to deploy a loop antenna we do have plenty of various length whip antennas and adaptor fittings that should make OTM, BLOS tactical communications commonplace in the Army.

Myth 8–HF doctrine does not exist in the U.S. Army.

–False again. Despite Soviet Admiral Sergei I. Gorshkov’s often quoted dictum that it is “fruitless to study U.S. doctrine because they don’t study it and if they did would feel no obligation to follow it”. In this case doctrine is there and valid. There is a huge list of field manuals, technical manuals, military handbooks and training aids that detail solid doctrinal concepts in HF communications that are available. On top of that there is an equally huge pile of similar doctrine in DoD and other service publications. Some of this information dates back well into the early 1920s. Lack of doctrine cannot be an excuse for S/G-6s not to employ tactical HF communications.

Over the past three-plus decades (roughly the time the Signal Center and School moved from Fort Monmouth to Fort Gordon), belief in these myths has been handed down from generation to generation of Signal Officers until “HF is no damn good” has become a mantra recited by the uninformed in order to conceal their lack on knowledge and education. This is the root cause of why Wallace was not able to emulate the performance of Guderian, Rommel and the Panzer’s of the 1930s not the lack of doctrine or equipment.

Sadly, the Army has deployed across the force many of the elements that were needed to solve the communications OTM problem that Wallace so eloquently presented to both the Signal Symposium and in his testimony to Congress. More sadly still much of what was required was present and under Wallace’s own command at the time he needed it so desperately. Specifically elements present that should have solved the problem were:

1–Skimpy but adequate quantities of HF radios to provide OTM/BLOS HF communications over corps/theater size areas from corps to battalion level if anyone cared to locate them. This equipment is on the unit Table of Organization and Equipment.

2–Doctrine that laid out the correct net radio structure to provide multiple HF communications paths from where the bridge information existed to where it was needed if anyone cared to read it.

3–Procedures required to get the correct antennas configured and the radio equipment on the air in the OTM/BLOS mode–if anyone cared to implement them.

What was not present and caused the critical breakdown in communications was:

1–Education–The Army no longer conducts an military occupational specialty producing course called Radio and Microwave System Officer (0505) as it did in the 60s and 70s. This hurts in an Army that uses combat net radios for almost everything on the battlefield. The idea of calling CNR “user-owned and operated” is bankrupt. Radio communications is not a trivial subject and to learn it to a level required for effective use in combat Signal officers, warrant officers and senior NCOs need to be better educated–particularly in the basic fields of radio physics/systems engineering, antennas, radio-wave propagation and frequency engineering. These subjects cannot be given the rush treatment during initial training as we do today. Each requires hard time in the classroom. This doesn’t mean everyone in Signal needs to have a bachelor of science in electrical engineering but it does mean far more instruction than we give now and at a far higher level–particularly for OTM and BLOS communications such as HF and SATCOM. Signal personnel educated this way would have in this situation been able to analyze the tactical situation and had the right CNR (HF) and the right antenna, and the right frequency assignment ready to go as the situation developed. If it is beyond the Army’s current capability to educate to this level then we should consider contracting a local community college or technical school to deliver the proper instruction. This needs to be backed up with a takeaway package of technical publications and computer-based training that is retained by each graduate for use in the field. This is not new and is currently implemented by other services.

2–Training–For far too long the Signal Corps idea of training has been teaching students what button to push, or what module/box to change. What we have failed to teach is the “why”. In many cases Signal personnel cannot explain why they are doing what they are doing-they are just doing it by rote when it comes to CNR systems. A logical thinking process and a reasonable knowledge of how things work is just not being imparted to many (not all) of our signal soldiers. When these personnel get to field (S-6) assignments they are expected to be the commanders technical experts with all communications/automation equipment whether it is owned by the user or not. Often they fail with CNRs through no fault of their own because they have not seen this “user” radio equipment before. When as so often happens in deployed situations something unusual happens, the button–pushers and the module changers are stymied because they have no training in a logical method that will isolate CNR system problems and fix them based on knowing the equipment and how it works. Additionally, personnel trained this way are not prepared to jump into situations like the one that faced Wallace with innovative technical applications to fit unique tactical situations on the fly. For many years, I have heard numerous senior Signal officers say essentially “you really never learn this stuff until you get to a unit and you’re on the job”. The incident at the Iraqi bridge proves that our branch “OJT” concept is as bankrupt as the “user-owned-and-operated” concept. Hoping for the best is just not a course of action that works. Hard time in the classroom backed up by field training is the only thing that does prepare a Signal soldier for combat operations.

The situation that Wallace talks about is not new. In fact it is roughly equivalent to the famous Operation Market Garden of World War-II depicted in the film A Bridge Too Far. In both operations higher headquarters knew the tactical situation confronting the forward force well because of air reconnaissance and similar high command resources. What failed in both cases was the supporting signal organizations ability to use on-hand, existing, CNR systems to establish radio communications between forward and supporting forces that were BLOS but really not that far away. In 1944 GEN Omar Bradley stated to his subordinate commanders after the Market Garden force had been extricated “It took an act of Congress to make you officers and gentleman it takes communications to make you a commander.” Truer words were never spoken.

We failed Wallace in this instance. He knows it. It was a small but significant action in a big operation but he is focused on it. The force and the Signal staff recovered from the shortfall in combat communications and moved on to take the bridge eventually but with some difficulty. The force and the Signal staff continued the fight until we won the war. The failure was however indicative (at least to Wallace) that something was very wrong with combat communications and the Signal Corps. Wallace would not have brought this up before the Congress of the United States and again at the 2003 Signal Symposium if he were not highly concerned.

What we need to do is listen to what the general is saying and fix it with the resources we have on hand today. This includes:

1) getting more HF hardware and putting it where it needs to be,

2) building a working systems architecture for all Army organizations,

3) building unit TOEs that track the systems architecture,

4) having operations and organizational concepts that track the SA and the TOE, and

5) by dispelling the myths about HF radio systems shown above through a well thought out professional CNR education and training program,

6) by replacing in the Signal Corps the bankrupt concepts of “user owned and operated” and “on the job professional signal training” with level appropriate knowledge and experience and by providing CNR sustainment training on a regular basis to signal staffs in their field locations.

We need to remember in this age when the “technology junkies” seem to rule our thinking with their exotic networking and information transfer ideas that the simple CNR is as basic to the Signal Corps as the rifle is to the infantry. Often in Blitzkrieg operations like OIF the network centric way of fighting is out the window (Wallace talks about this in his presentation also) and the simple HF-CNR is the only system that can get the minimum essential traffic through -even if the force is moving and spread BLOS. The HF radio has the characteristics that can hold highly mobile operations together over any kind of battlefield until more elaborate higher volume systems can be deployed. The famous Signal dictum of PACE (primary, alternate, contingency, emergency) is a very valid concept that includes HF and all CNRs (VHF/UHF etc.).

In order to be responsive to changing battlefield situations and maintain our credibility with the commanders, signal personnel need to understand all systems (including the humble single channel HF radio) and be able to fit the tool to the job. On the battlefield you never know what system will have to carry the ball for a commander who needs to communicate.


ALE–Automatic Link Establishment

AMEDD–Army Medical Department

AVN–Army Aviation



C2–command and control

C3–command, control and communications

CNR–combat net radios

CP–command post

DoD–Department of Defense

DSP–digital signal processing

HF–high frequency

LOS–line-of sight

MELP–Mixed Excitation Linear Predictive

MOS–military occupational specialty

NVIS–Near Vertical Incidence Sky-wave

O&O–operations and organizational



PACE–primary, alternate, contingency, emergency

SA–systems architecture

SATCOM–satellite communications

SIDs–sudden Ionospheric disturbances

SOF–Special Operations Forces Forces

TOC–Tactical Operations Centers

TOE–Table of Organization and Equipment

UAVs–unmanned aerial vehicles

Mr. Fiedler–a retired Signal Corps lieutenant colonel–is an engineer and project director at the project manager for tactical-radio communications systems, Fort Monmouth. Past assignments include service with Army avionics, electronic warfare, combat-surveillance and target-acquisition laboratories, Army Communications Systems Agency, PM for mobile-subscriber equipment, PM-SINCGARS and PM for All-Source Analysis System. He’s also served as assistant PM, field-office chief and director of integration for the Joint Tactical Fusion Program, a field-operating agency of the deputy chief of staff for operations. Fiedler has served in Army, Army Reserve and Army National Guard Signal, infantry and armor units and as a DA civilian engineer since 1971. He holds degrees in both physics and engineering and a master’s degree in industrial management. He is the author of many articles in the fields of combat communications and electronic warfare.

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