Abstract
Satellite networks play a vital role in enabling essential critical infrastructure services that include public safety; environmental monitoring; maritime disaster recovery and reconnaissance; electronic surveillance; and intelligence operations for law enforcement, the military, and government agencies (Jamalipour & Tung, 2001). As demonstrated by the events following the terrorist attacks in the U.S. on the Pentagon in Washington, D.C. and the World Trade Center in New York City on September 11, 2001, satellite networks also provide redundant communications services when terrestrial networks are disrupted and/or unavailable. Despite their merits, satellite networks are nonetheless vulnerable to cyber attacks that pose threats to national security and the economy. Satellite networks transport voice, video, images, and data through the air as electromagnetic signals, thereby making these transmissions susceptible to interception. Technical advances enable the interconnectivity of satellite systems to public and private wireless and terrestrial networks including the Internet. These advances, however, amplify the risk of cyber attacks that can compromise critical infrastructure functions dependent on satellite networks in sectors that include information technology (IT) and telecommunications; defense; government; banking and finance; utilities; agriculture; emergency services; public health; and transportation (U.S. Department of Homeland Security (DHS), 2003; U.S. Government Accounting Office (GAO), 2004). As a consequence, satellite networks employ an array of security tools and mechanisms for countering costly and widespread cyber incursions and, thereby, ensuring the continuity of critical infrastructure operations. Those cyber attacks that are politically motivated and specifically designed to disrupt essential services are generally attributed to cyber terrorism. This chapter describes the technical fundamentals of satellite networks; examines security vulnerabilities; and explores initiatives for protecting the integrity of satellite network transmissions and operations from cyber incursions and physical attacks. Standards and protocols that safeguard satellite networks from unauthorized use and intentional disruptions and policies, and legislation that facilitate cyberspace asset protection are described. Capabilities of encryption in supporting secure satellite services and the distinctive attributes of the InterPlanetary Internet (IPN), also called the InterPlanetary Network, are explored.
TopIntroduction
Satellite networks play a vital role in enabling essential critical infrastructure services that include public safety; environmental monitoring; maritime disaster recovery and reconnaissance; electronic surveillance; and intelligence operations for law enforcement, the military, and government agencies (Jamalipour & Tung, 2001). As demonstrated by the events following the terrorist attacks in the U.S. on the Pentagon in Washington, D.C. and the World Trade Center in New York City on September 11, 2001, satellite networks also provide redundant communications services when terrestrial networks are disrupted and/or unavailable. Despite their merits, satellite networks are nonetheless vulnerable to cyber attacks that pose threats to national security and the economy.
Satellite networks transport voice, video, images, and data through the air as electromagnetic signals, thereby making these transmissions susceptible to interception. Technical advances enable the interconnectivity of satellite systems to public and private wireless and terrestrial networks including the Internet. These advances, however, amplify the risk of cyber attacks that can compromise critical infrastructure functions dependent on satellite networks in sectors that include information technology (IT) and telecommunications; defense; government; banking and finance; utilities; agriculture; emergency services; public health; and transportation (U.S. Department of Homeland Security (DHS), 2003; U.S. Government Accounting Office (GAO), 2004). As a consequence, satellite networks employ an array of security tools and mechanisms for countering costly and widespread cyber incursions and, thereby, ensuring the continuity of critical infrastructure operations. Those cyber attacks that are politically motivated and specifically designed to disrupt essential services are generally attributed to cyber terrorism.
This chapter describes the technical fundamentals of satellite networks; examines security vulnerabilities; and explores initiatives for protecting the integrity of satellite network transmissions and operations from cyber incursions and physical attacks. Standards and protocols that safeguard satellite networks from unauthorized use and intentional disruptions and policies, and legislation that facilitate cyberspace asset protection are described. Capabilities of encryption in supporting secure satellite services and the distinctive attributes of the InterPlanetary Internet (IPN), also called the InterPlanetary Network, are explored.
TopBackground
Satellite Network Technical Fundamentals
Satellite networks consist of ground and space segments. The ground segment includes a ground or earth station that delivers communications services and monitors satellite operations by providing tracking, telemetry, and control (TT&C) functions. The space segment consists of the artificial satellite and its payload.
In contrast to a natural satellite or a celestial body that revolves around a larger sized planet, an artificial satellite is a wireless receiver/transmitter that orbits the earth and employs microwave technology in the super high and extremely high radio frequency (RF) bands of the electromagnetic spectrum to enable wide area interactive communications (Littman, 2002). The payload includes transceivers and antennas for RF signal reception, amplification, and retransmission.
The quality of the satellite signal reflects the quality of the uplink and downlink. An uplink describes signal transmissions from an earth station such as a gateway, teleport, hub, or very small aperture terminal (VSAT) to the satellite. A downlink refers to signal transmissions from the satellite to the designated reception site. Typically, satellite transmissions are asymmetrical with more information transported on the downlink than on the uplink (Littman, 2002). Generally classified in terms of the orbits in which they operate, satellite constellations are categorized as geosynchronous or geostationary earth orbit (GEO), medium earth orbit (MEO), and low earth orbit (LEO).
Key Terms in this Chapter
Space Segment: Refers to the artificial satellite and its payload in a satellite network. It enables diverse applications in sectors that include e-government, e-learning, and e-medicine.
Open Systems Interconnection (OSI) Reference Model: Seven-layer architectural model developed by the International Organization for Standardization (ISO) to describe standardized network operations.
Low Earth Orbit (LEO): Satellite constellations that orbit the earth at altitudes ranging from 500 km to 900 km and support applications such as Internet connectivity.
IPv6: Developed by the IETF. IPv6 extends IP addresses from 32-bits to 128-bits, thereby overcoming IPv4 address shortages and ensuring continued Internet growth and expansion.
Cyber Attack: A computer network attack that involves the use of wireline and/or wireless network connections to gain unauthorized access to computing resources in order to control network operations ( Wilson, 2005 ).
Medium Earth Orbit (MEO): Mid-sized satellite constellations such as the U.S. Global Positioning System (GPS). GPS satellites maintain orbits at approximately 20,200 km above the earth and provide precise positioning services.
Ground Segment: Terrestrial component in a satellite network that manages and controls satellite operations and processes data for storage and transmission.
Geostationary or Geosynchronous Earth Orbit (GEO): A satellite constellation with three to five satellites that orbit the earth at altitudes of 35,800 kilometers (km) such as military strategic and tactical relay satellite (MILSTAR) that provides jam-resistant communications services for the U.S. military.