Army Cyber Institute - HF radio can take up slack, ARS contributes

Discussion in 'Amateur Radio News' started by W0PV, Feb 3, 2020.

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  1. W0PV

    W0PV Ham Member QRZ Page

    This article recently published online in the Armed Forces Communications and Electronics Association (AFCEA) journal SIGNAL should also be of interest to the Amateur Radio Service community.

    The principle author is a US Army officer and research scientist at West Point, and apparently also FCC licensed as call sign KJ5HY.

    I believe it favorably underlines the FCC ARS Part 97.1 Basis and Purpose. In the text below I have highlighted some of the most relevant statements well known by, regarding or affecting the ARS.

    Hope you find it interesting.

    73, John, WØPV


    High Frequency Communications Features Highs and Lows

    By Col. Stephen Hamilton, USA ( @KJ5HY ), and Chief Warrant Officer 4 Judy Esquibel, USA - February 1, 2020

    If satellite links go down, HF radios can take up the slack.

    As cyber threats continue to grow, so does the reality that digital satellite communications can be degraded and denied either through digital or electromagnetic means. If these capabilities are compromised, however, high frequency radio provides a means to continue communicating even beyond the line of sight by leveraging the ionosphere to refract radio signals back to earth.

    The International Communication Union Telecommunication Standardization Sector designates the high frequency (HF) range as between 3 megahertz and 30 megahertz. While this method of communication was utilized extensively up through the 1990s, it began to lose traction in the military when the availability of satellite communications (SATCOM) increased.

    Among the key differences between HF, very high frequency (VHF) and ultrahigh frequency (UHF) are the multiple antenna configurations required to radiate the signal properly in HF and the atmospheric conditions that greatly affect the propagation of the signal. In addition, choosing the correct frequency for the time of day plays a crucial role in setting up HF communications. Under these conditions and given the proper setup, HF radio signals can be targeted to a geographical region, enabling beyond line-of-sight communication without using satellites.

    The growing dependency on SATCOM presents a problem: Because warfighters have been training for SATCOM, the training for effectively employing HF radio has dwindled; radios in the VHF and UHF range have continued to be used for line-of-sight communications.

    According to Ronald C. Wilgenbusch and Alan Heisig in an article in Joint Force Quarterly,
    HF is not a viable option to SATCOM, and they agree the declining amount of training is an issue. “The worldwide system of fixed HF transmitters and antennas that was once the mainstay of our HF communications systems is gone. … Even if it was still in place, the skilled HF operators needed aboard ships and ashore have been cashing retirement checks for years,” they said.

    the windfall of baby boomer retirements is challenging all government and commercial sectors, it has been especially hard on the computer industry. However, even though many HF-trained military members are separating from the services, a younger generation of enthusiasts is coming from the intersection of do-it-yourself aficionados and hackers. They are tinkering and creating small electronic devices, often using software-defined radios in their projects. They also are exploring various radio frequency-HF communication techniques and developing new hybrid skills.

    Even the National Natural Science Foundation of China concluded that HF radio use will lead to self-adaptability and an ever-changing environment. HF radio use also will encourage and leverage machine learning approaches, which will result in the development of smart anti-jamming techniques and equipment.
    In addition, foundation members believe heterogeneous networking—a combination of HF communications and satellite communications, military networks and civil cellular communications—will enable an integrated space-air-marine-ground communication network.

    HF communication using digital modes like FT8 is an example of how techniques evolve with digital communications. The ham and hacker communities have stated that evolving methods could enhance global communications while improving the use of limited spectrum.

    There is a trade-off, however. HF data rates are far lower than SATCOM data rates. Consequently, a backup plan must not only detail how to utilize HF transmissions but also outline what data should be transmitted.

    For example, it may not be possible to transmit the 2-megabyte battle brief of a PowerPoint slideshow using HF radio; however, the text from the slides could be transmitted without graphics over HF radio. In addition to bandwidth constraints, directing an HF signal to a specific location requires attention to many factors, including frequency, antenna configuration and power.

    Using HF radios for communication also poses other challenges that require process and equipment planning. For example, HF radio communications at shorter distances where the environment obstructs line of sight is possible with near vertical incidence skywave (NVIS) propagation. The government communications uses NVIS and has a skywave radio-wave propagation that provides usable signals at distances of up to 400 miles.

    The Army Cyber Institute, West Point, New York, recently conducted HF NVIS testing at the National Training Center in Fort Irwin, California. The test included the software JS8Call, the open source program WSJT-X and single sideband modulation voice communication.

    To guarantee the propagation was true NVIS, the institute’s team placed stations on either side of Tiefort Mountain and verified that VHF communication was not possible. The team then utilized results from Voice of America Coverage Analysis Program prediction software to determine the proper frequency for the time of day and used a sloped dipole antenna configuration for the NVIS link. The voice link was easily established utilizing 50 watts of power.

    the institute’s team tested WSJT-X to validate FT8 digital communication, which worked as expected, and used JS8Call to send messages, which reduced power consumption considerably and continued to receive JS8Call messages flawlessly.

    HF NVIS has been called a “safety net under our infrastructure” that serves as the base layer national fallback network for regional and wide area communications for government, industry, public safety and critical infrastructure when primary systems fail. Initiatives like HF NVIS enable communications resilience and situational awareness within critical infrastructure defense during catastrophic events such as natural disasters, cyber attacks or electromagnetic pulse attacks.

    The U.S. Department of Homeland Security Cybersecurity and Infrastructure Agency SHAred RESources (SHARES) HF Radio Program is
    one example of this safety net. SHARES provides a 24-hour capability to provide an emergency communications link to support intra- or interagency mission requirements.

    Col. Stephen Hamilton, USA, (KJ5HY) is a cyber officer who currently is the technical director of the Army Cyber Institute. Chief Warrant Officer 4 Judy M. Esquibel, USA, is a cyber operations technician and doctoral student in the Department of Information Sciences, Naval Postgraduate School, Monterey, California, and an Army Cyber Institute Fellow.


    de WØPV -> also related earlier published article - Bringing Communications Back Down to Earth

    The authors are KB3UMN and KJ4AYT. Relevant comments from that article,

    KEN WYATT WROTE ON WED, 06/06/2018 - 01:12
    I suspect amateur radio operators could jump in as instructors, or even emergency operators via the MARS organization, as they’ve been operating HF communications continuously since the early 1900s.

    Author KURT STEPHENS (@KJ4AYT) WROTE ON MON, 06/11/2018 - 10:37
    Ken, well said, there is a lot of talent within the Amateur and MARS ranks that can contribute to bringing training up to speed.
    Last edited: Feb 3, 2020
    N0TZU, VE3GZB, KR3DX and 7 others like this.
  2. KU4X

    KU4X Premium Subscriber QRZ Page

    From the above-mentioned article:
    "For example, it may not be possible to transmit the 2-megabyte battle brief of a PowerPoint slideshow using HF radio..."

    "PowerPoint makes us stupid" - GEN James Mattis (USMC, Retired)

    Apparently, the Army CyberGurus are not up-to-date on their military reading. ;)

    N4AFK and N3LAC like this.
  3. KA2IRQ

    KA2IRQ Ham Member QRZ Page

    Just out of curiosity, has anyone ever studied how a nuclear blast affects the ionosphere and HF radio communications? And if so, for how long? (Excluding the effects of EMP.)
  4. WQ4G

    WQ4G Ham Member QRZ Page

    Yes, it has been studied by the U.S. Government. The effects of the detonation of a Nuclear Weapon depends on the yield of the blast, the altitude of detonation, and to some extent the latitude of the detonation.

    More information can be found at:

    Dan WQ4G
    AI4HO, VE3GZB, YD1LKB and 3 others like this.
  5. KM4DYX

    KM4DYX Ham Member QRZ Page

    The article was very interesting and thank you for posting it.

    KR3DX and PE1KWE like this.
  6. W1YW

    W1YW Ham Member QRZ Page

    A little surprised to see this expressed publicly....but the point is well taken:

    K8XG and W0PV like this.
  7. AI5DH

    AI5DH Ham Member

    HF will live, ham radio operators are irrelevant and the military has no use for.
    WJ2L and W3CUB like this.
  8. W1YW

    W1YW Ham Member QRZ Page

    All I can say is that is incorrect. No argument desired nor intended.

    The AFCEA piece is a message, not a desire.

    Chip W1YW
    Last edited: Feb 4, 2020
    KY5U and WQ4G like this.
  9. KL7AJ

    KL7AJ Ham Member QRZ Page

    Look up Link-16 protocol. Text messaging on steroids.
    VE3GZB likes this.
  10. N0NC

    N0NC Premium Subscriber QRZ Page

    Quote"The worldwide system of fixed HF transmitters and antennas that was once the mainstay of our HF communications systems is gone. … Even if it was still in place, the skilled HF operators needed aboard ships and ashore have been cashing retirement checks for years,” /quote. They said we don't need that old technology, we got this great new thing called SATCOM.

    Maybe they should have considered this before tearing out all that infrastructure.

    They liked FT8. How would they transmit a 2 megabyte battle plan power point presentation with that?
    WB7SKK likes this.

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