Radio-Frequency Geo-location and Small Satellite Constellations

Abstract

The worldwide responsibility for the allocation of radio frequencies and the coordination of their use is assigned to the International Telecommunication Union (ITU), headquartered in Geneva, Switzerland. The ITU plenary assembly known as theWorld Radiocommunication Conference meets every few years and agrees on the global radio-frequency allocations to be used globally. The spectrum allocations are divided into three regions globally as follows: region 1, Europe and Africa; region 2, the Americas; and region 3, Asia and Australasia. The usage for radio-frequency spectra has grown enormously in recent years for terrestrial wireless usage (i.e., the of 5G broadband cellular services, emergency and first responder services, law enforcement and defense-related applications, radio and television broadcasting, non-licensed industrial and scientific usage, and microwave relay). There has been parallel growth of non-terrestrial uses such as for aviation communications and safety, high-altitude platform systems and UAVs, plus satellites of various types. The complexity of the global frequency a allocation tables has increased enormously as well as the problem of frequency interference and jamming. More and more types of shared usages have emerged, and higher and higher frequencies in the electromagnetic spectrum have been allocated to these many and growing applications. As this increase in usage and types of applications has emerged, there has been growing concerns and difficulties of unintended and intended interference, jamming, and disagreements between nations and other groups and commercial interests about how to coordinate spectrum use. There are increasingly challenging discussions globally about the best processes related to frequency allocations, frequency allotments, and frequency assignments (or national licensing practices). Terrestrial systems for monitoring the usage of radio-frequency spectra are increasingly inadequate to the task of accurately and precisely determining the nature and exact location this usage. Further the deployment of a significant number of new small satellite constellations will likely increase the problem of monitoring of spectrum use and interference in coming years. It has been decided that one way to monitor radio-frequency spectrum use much more effectively on a global scale is the deployment of satellites that can consistently monitor frequency use around the world and also identify spectrum that is not being used or underutilized in various parts of the world. The first such satellite-based commercial system to seek to provide comprehensive and near real-time monitoring of frequency use - or misuse - on a global scale is the small satellite constellation known as Hawkeye 360. This low Earth orbit satellite constellation and its types of service offerings are described below. This chapter reports on the issue of increasing need for global frequency use and monitoring and the latest efforts to monitor spectrum usage using satellite networks designed and operated for this purpose. The Hawkeye 360 system and its intended special ability to deliver actionable data to national administrations, commercial interests, and perhaps even defenserelated interests around the world on a near real-time basis are also discussed. This rapid delivery of monitoring results is to be accomplished by making arrangements with new commercial data relay constellations designed to provide near real-time information to ground stations deployed around the world that can then connect to users of this data. This arrangement avoids the need to wait to download results until the LEO-based satellite is over a particular accessible ground antenna system. This type of commercially based frequency monitoring service, of course, could be performed by other entities in the future, but currently the Hawkeye 360 is uniquely providing this type of service on a commercial basis. Currently the greatest problem of frequency interference and jamming typically occurs with regard to terrestrial radio and television broadcasts and other types of interference and jamming problems near the ground. Nevertheless the deployment of more and more satellites, high-altitude platforms, and the use of space planes and hypersonic transportation will increasingly bring these problems to near-space (i.e., Protospace) and outer space. There is increasing concern about the issue of space debris; congestion of Earth orbits, especially low Earth orbit; and space traffic management or space traffic control. The problem often focuses on the issue of physical collisions, but frequency interference or jamming or cyberattack could also lead to accidents in space and the disabling of satellites or lead to physical collisions. Thus frequency monitoring and control in space are also going to be increasingly important as these future trends develop.