The mobile satellite service (MSS) systems for global personal communications

A worldwide interest has arisen on personal communications via satellite systems. The recently proposed mobile satellite service(MSS) systems are categorized four areas: geostationary earth orbit(GEO) systems, medium earth orbit(MEO) systems, low earth orbit(LEO) systems, and highly elliptical orbit(HEO) systems. Most of the systems in each category are introduced and explained including some technical details. The communication links and orbital constellations of some systems are analyzed and compared with different categories, and with different systems. Some economical aspects of the systems are mentioned. The regulatory issues about frequency spectrum allocation, and the current technical trends in these systems are summarized

Unmanned Insecurity: The Safety and Privacy Issues of Unmanned Aircraft Information Assurance

Information assurance and computer security are foundational paradigms in ground based information systems. However, in the aerial realm of unmanned systems, information security often takes the proverbial back seat to high visibility issues such as safety and privacy. Yet, a secure unmanned aircraft is a basic tenant of safety and privacy in the operational arena. Information assurance and security that are enveloped into an unmanned aircraft protect the systems data, communications, as well as internal operations and permeates not only the aircraft’s systems, but also the system’s interactions with satellites, ground stations, and other aerial entities that share data and communication streams with the UAS. This paper will discuss the vital foundational information assurance and security elements of unmanned aerial systems and how these elements relate directly to UAS safety, privacy, reliability, and resilience. It will present case based research of unmanned and manned aircraft mishaps, from both the military and civilian domains, that demonstrate the centrality of security to a safe and viable operational aircraft. It will also demonstrate how privacy issues stem directly or indirectly from information assurance and computer security breaches in an unmanned aircraft. Such breaches of privacy can lead to such issues as privacy torts, theft of intellectual property, Constitutional violations, and issues of personal safety and security from exposed data and communication streams. Additionally, information security breaches can also lead to a hostile takeover of the UAS by a malicious third party, or improper systems functioning of the aircraft leading to myriad public safety issues such as a downed UAS, the uncontrolled flight of the UAS in controlled airspace, or at worse the collision of the UAS into a manned aircraft resulting in a catastrophic outcome. This paper will also discuss the mechanisms of information security in an unmanned aerial system as well as its corresponding ground station and satellite communication systems. It will trace security issues directly to issues of safety and privacy and provide methodologies to improve UAS information security to improve system safety and data security to eliminate negative outcomes from operational UAS missions. Additionally, the paper will provide guidance on holistic UAS operational security, through the maintenance of confidentiality, availability, and integrity via policy, technological, and physical security mechanisms