I found this interesting blurb on the Sunair website: WHY HF? Prior to the launch of communications satellites in the 1960s, high frequency (HF) radio was the principal means to communicate over the horizon. Satellite links permitted users to communicate at higher data rates, and over time HF was relegated to a backup role within the militaries of the United States, Western Europe, and the former Soviet Union. However, the limitations of satellites became clear in the Cold War era, as satellites were not only vulnerable to jamming and physical damage, but also required a supporting infrastructure that was expensive to build and maintain. The last two decades have resultantly seen resurgence in HF radio, led by a new generation of automated equipment with improved link reliability, connectivity, and speed that offered many of the benefits of satellite technology at a fraction of the overall cost. HF now serves as the principal backup in most ground- and ship-based configurations, and the primary backup in installations prioritizing lowest total cost of ownership. Today, amidst the post 9/11 requirements for continuity of operations and a failsafe means of voice and data communication, HF equipment serves as a critical component in most emergency preparedness wireless communications plans. HF radio provides an additional layer of protection against total loss of communication when infrastructure-dependent communications are disabled, destroyed, or unavailable. Benefits of HF Technology MINIMAL INFRASTRUCTURE REQUIREMENTS An HF radio network requires absolutely no infrastructure. Unlike conventional land lines, cellular and satellite telephones, and Voice Over IP, an HF radio user can communicate with another HF radio user without any infrastructure apart from the equipment and housing area, minimizing both cost and susceptibility to damage. MINIMAL COST OF OWNERSHIP HF is the most economical means of failsafe communication. After the initial investment in equipment and installation is made, there are no call or line costs. Furthermore, Sunair HF equipment is ruggedized and built to withstand extreme conditions over many years, thereby significantly reducing costs of the usage period. TRUE HEMISPHERIC COVERAGE HF, or short-wave, radio is the best suited technology to communicate over long distances. When coupled with Sunair solid-state 5 and 10 kilowatt amplifiers, HF can serve as a primary or emergency means of communication to and from any point in the world. SURE AND SECURE COMMUNICATIONS For sensitive communications where security is essential, voice and data encryption is a readily available option with HF radio. Sunair customers have used our product with third party encryption packages for years, with differing levels of security based on the respective communications requirement. FULL FEATURED In addition to voice, HF radios come with options that allow for telephone, fax, email, and high speed data. INTEROPERABILITY HF radios can communicate with existing VHF and UHF systems, cellular telephones and land lines through developments in cross-patching technology. .