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MIL-STD-188
MIL-STD-188 is a series of U.S. military standards relating to telecommunications. Purpose Faced with "past technical deficiencies in telecommunications systems and equipment and software…that were traced to basic inadequacies in the application of telecommunication standards and to the lack of a well defined…program for their review, control and implementation", the U.S. Department of Defense looked to develop a series of standards that would alleviate the problem. By 1988, the U.S. Department of Defense (DoD) issued Instruction 4630.8 (reissued in 1992, 2002, 2004) stating its policy that "all forces for joint and combined operations be supported through compatible, interoperable, and integrated Command, Control, Communications, and Intelligence systems. … nd that all suchsystems developed for use by U.S. forces are considered to be for joint use." To achieve this the director of the Defense Information Systems Agency (DISA) is charged with "developing information techn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Link Establishment
Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels. Mechanism A standalone ALE radio combines an HF SSB radio transceiver with an internal microprocessor and MFSK modem. It is programmed with a unique ALE address, similar to a phone number (or on newer generations, a username). When not actively in contact with another station, the HF SSB transceiver constantly scans through a list of HF frequencies called ''channels'', listening for any ALE signals transmitted by ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS-422
RS-422, also known as TIA/EIA-422, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. It was meant to be the foundation of a suite of standards that would replace the older RS-232C standard with standards that offered much higher speed, better immunity from noise, and longer cable lengths. RS-422 systems can transmit data at rates as high as 10 Mbit/s, or may be sent on cables as long as at lower rates. It is closely related to RS-423, which uses the same signaling systems but on a different wiring arrangement. RS-422 specifies differential signaling, with every data line paired with a dedicated return line. It is the voltage difference between these two lines that define the mark and space, rather than, as in RS-232, the difference in voltage between a data line and a local ground. As the ground voltage can differ at either end of the cable, this required RS-232 to use signals with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defense Information Systems Agency
The Defense Information Systems Agency (DISA), known as the Defense Communications Agency (DCA) until 1991, is a United States Department of Defense (DoD) combat support agency composed of military, federal civilians, and contractors. DISA provides information technology (IT) and communications support to the President, Vice President, Secretary of Defense, the military services, the combatant commands, and any individual or system contributing to the defense of the United States. Headquarters From January to July 2011, DISA relocated more than 4,500 military and civilian employees and supporting onsite contractors, 700 workstation suites with 11,000 pieces of IT equipment, and 58,000 square feet of lab equipment in accordance with the Base Realignment and Closure legislation of 2005. The relocation to Fort George G. Meade, Md., consolidated DISA headquarters elements that were housed in multiple locations in Arlington and Falls Church, Va. In April 2011, DISA held a ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combat-net Radio
In telecommunication, a combat-net radio (CNR) is a radio operating in a network that (a) provides a half-duplex circuit and (b) uses either a single radio frequency or a discrete set of radio frequencies when in a frequency hopping mode. CNRs are primarily used for push-to-talk-operated radio nets for command and control of combat, combat support, and combat service support operations among military ground, sea, and air forces. In the United States, two military standards govern the use of combat net radios and the host applications that communicate over the network: MIL-STD-188-220 and MIL-STD-2045-47001. In addition to IETF RFCs governing UDP, TCP, and IPv4/IPv6, all seven layers of the OSI communications architecture are addressed. MIL-STD-2045-47001 covers layer 7 (application), while MIL-STD-188-220 covers layers 1 through 3 (physical, data link, and network). Examples * AN/PRC-152 by Harris Corporation *AN/PRC-117 * AN/PRC-77 *SINCGARS * AN/PRC-148 MBITR *PR4G by Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Imagery Transmission Format
The National Imagery Transmission Format Standard (NITFS) is a U.S. Department of Defense (DoD) and Federal Intelligence Community (IC) suite of standards for the exchange, storage, and transmission of ''digital-imagery'' products and ''image-related'' products. DoD policy is that other image formats can be used internally within a single system; however, NITFS is the default format for interchange between systems. NITFS provides a package containing information about the image, the image itself, and optional overlay graphics. (i.e. a "package" containing an image(s), subimages, symbols, labels, and text as well as other information related to the image(s)) NITFS supports the dissemination of secondary digital imagery from overhead collection platforms. Guidance on applying the suite of standards composing NITFS can be found in MIL-HDBK-1300A, National Imagery Transmission Format Standard (NITFS), 12 October 1994. The NITFS allows for Support Data Extensions (SDEs), which are a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Pulse
An electromagnetic pulse (EMP), also a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. Depending upon the source, the origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an electric field, as a magnetic field, or as a conducted electric current. The electromagnetic interference caused by an EMP disrupts communications and damages electronic equipment; at higher levels of energy, an EMP such as a lightning strike can physically damage objects such as buildings and aircraft. The management of EMP effects is a branch of electromagnetic compatibility (EMC) engineering. EMP weapons are designed to deliver the damaging effects of a high-energy EMP that will disrupt unprotected infrastructure in the country, thus the employment of an EMP weapon against a country is the scenario of war most likely to collapse the functionality of the electrical network of the country. General characteristics An ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Of The United States Standards
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct military uniform. It may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of the military is usually defined as defence of the state and its interests against external armed threats. In broad usage, the terms ''armed forces'' and ''military'' are often treated as synonymous, although in technical usage a distinction is sometimes made in which a country's armed forces may include both its military and other paramilitary forces. There are various forms of irregular military forces, not belonging to a recognized state; though they share many attributes with regular military forces, they are less often referred to as simply ''military''. A nation's military may f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bits Per Second
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction with an SI prefix such as kilo (1 kbit/s = 1,000 bit/s), mega (1 Mbit/s = 1,000 kbit/s), giga (1 Gbit/s = 1,000 Mbit/s) or tera (1 Tbit/s = 1,000 Gbit/s). The non-standard abbreviation bps is often used to replace the standard symbol bit/s, so that, for example, 1 Mbps is used to mean one million bits per second. In most computing and digital communication environments, one byte per second (symbol: B/s) corresponds to 8 bit/s. Prefixes When quantifying large or small bit rates, SI prefixes (also known as metric prefixes or decimal prefixes) are used, thus: Binary prefixes are sometimes used for bit rates. The International Standard (IEC 80000-13) specifies differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015. The term "JPEG" is an acronym for the Joint Photographic Experts Group, which created the standard in 1992. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media. JPEG compression is used in a number of image file formats. JPEG/ Exif is the most common image format used by digital cameras and other photographic image capture devices; along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MUOS
The Mobile User Objective System (MUOS) is a United States Space Force narrowband military communications satellite system that supports a worldwide, multi-service population of users in the ultra high frequency (UHF) band. The system provides increased communications capabilities to newer, smaller terminals while still supporting interoperability with legacy terminals. MUOS is designed to support users who require greater mobility, higher bit rates and improved operational availability. The MUOS was declared fully operational for use in 2019. Overview The Mobile User Objective System (MUOS), through a constellation of five satellites (four operational satellites and one on-orbit spare), provides global narrowband connectivity to terminals, platforms, tactical operators and operations centers. The system replaces the slower and less mobile 1990s-era Ultra High Frequency Follow-On (UFO) satellite communication system. MUOS primarily serves the United States Department of Def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demand Assigned Multiple Access
Demand Assigned Multiple Access (DAMA) is a technology used to assign a channel to clients that don't need to use it constantly. DAMA systems assign communication channels based on news issued from user terminals to a network security system. When the circuit is no longer in use, the channels are again returned to the central pool for reassignment to other users. Channels are typically a pair of carrier frequencies (one for transmit and one for receive), but can be other fixed bandwidth resources such as timeslots in a TDMA burst plan or even physical party line channels. Once a channel is allocated to a given pair of nodes, it is not available to other users in the network until their session is finished. It allows utilizing of one channel (radio or baseband frequency, timeslot, etc.) by many users sequentially ''at different times''. This technology is mainly useful with sparsely used networks of transient clients, as opposed to ''PAMA ( Permanently Assigned Multiple Access) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
