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VHF Data Link
The VHF Data Link or VHF Digital Link (VDL) is a means of sending information between aircraft and ground stations (and in the case of VDL Mode 4, other aircraft). Aeronautical VHF data links use the band 117.975–137 MHz assigned by the International Telecommunication Union to Aeronautical mobile (R) service. There are ARINC standards for ACARS on VHF and other data links installed on approximately 14,000 aircraft and a range of ICAO standards defined by the Aeronautical Mobile Communications Panel (AMCP) in the 1990s. Mode 2 is the only VDL mode being implemented operationally to support Controller Pilot Data Link Communications (CPDLC). ICAO VDL Mode 1 The ICAO AMCP defined this Mode for validation purposes. It was the same as VDL Mode 2 except that it used the same VHF link as VHF ACARS so it could be implemented using analog radios before VHF Digital Radio implementation was completed. The ICAO AMCP completed validation of VDL Modes 1&2 in 1994, after which the Mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telecommunication Union
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Union, making it the oldest UN agency. The ITU was initially aimed at helping connect telegraphic networks between countries, with its mandate consistently broadening with the advent of new communications technologies; it adopted its current name in 1932 to reflect its expanded responsibilities over radio and the telephone. On 15 November 1947, the ITU entered into an agreement with the newly created United Nations to become a specialized agency within the UN system, which formally entered into force on 1 January 1949. The ITU promotes the shared global use of the radio spectrum, facilitates international cooperation in assigning satellite orbits, assists in developing and coordinating worldwide technical standards, and works to improve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrier Sense Multiple Access
Carrier-sense multiple access (CSMA) is a medium access control (MAC) protocol in which a node verifies the absence of other traffic before transmitting on a shared transmission medium, such as an electrical bus or a band of the electromagnetic spectrum. Under CSMA, a transmitter uses a carrier-sense mechanism to determine whether another transmission is in progress before initiating a transmission. That is, it tries to detect the presence of a carrier signal from another node before attempting to transmit. If a carrier is sensed, the node waits for the transmission in progress to end before initiating its own transmission. Using CSMA, multiple nodes may, in turn, send and receive on the same medium. Transmissions by one node are generally received by all other nodes connected to the medium. Variations on basic CSMA include addition of collision-avoidance (CSMA/CA), collision-detection (CSMA/CD) and collision-resolution techniques. Access modes Variations of CSMA use differe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mode S
The aviation transponder interrogation modes are the standard formats of pulsed sequences from an interrogating Secondary Surveillance Radar (SSR) or similar Automatic Dependent Surveillance-Broadcast (ADS-B) system. The reply format is usually referred to as a "code" from a transponder, which is used to determine detailed information from a suitably equipped aircraft. In its simplest form, a "Mode" or interrogation type is generally determined by pulse spacing between two or more interrogation pulses. Various modes exist from Mode 1 to 5 for military use, to Mode A, B, C and D, and Mode S for civilian use. Interrogation modes Several different RF communication protocols have been standardized for aviation transponders: Mode A and Mode C are implemented using air traffic control radar beacon system as the physical layer, whereas Mode S is implemented as a standalone backwards-compatible protocol. ADS-B can operate using Mode S-ES or Universal Access Transceiver as its transport ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeronautical Information Management
Aeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies the aspects of "aeronautical Art, Science and Engineering" and "The profession of Aeronautics (which expression includes Astronautics)." While the term originally referred solely to ''operating'' the aircraft, it has since been expanded to include technology, business, and other aspects related to aircraft. The term "aviation" is sometimes used interchangeably with aeronautics, although "aeronautics" includes lighter-than-air craft such as airships, and includes ballistic vehicles while "aviation" technically does not. A significant part of aeronautical science is a branch of dynamics called aerodynamics, which deals with the motion of air and the way that it interacts with objects in motion, such as an aircraft. History Early ideas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Håkan Lans
Anders Håkan Lans (born 2 November 1947 in Enskede) is a Swedish inventor. He holds two patents: * a memory controller for a framebuffer: "Data processing system and apparatus for color graphics display". Framebuffer with memory controllers had been in common use for years at the time of this 1979 patent filing. * a calligraphic display "Arrangement for producing a pattern on a light-sensitive surface" STDMA Håkan Lans is the designer of a tracking system which makes use of a Self-Organized Time Division Multiple Access (STDMA) datalink. The STDMA datalink is currently in use in Automatic Identification System (AIS). AIS is a short range coastal tracking system which is mandatory aboard international voyaging ships with gross tonnage (GT) of 300 or more tons, and all passenger ships regardless of size. STDMA is also in use as one of the three physical layer models proposed for Automatic dependent surveillance-broadcast (ADS-B), a cooperative surveillance technique for air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, ; fi, Ruotsi; fit, Ruotti; se, Ruoŧŧa; smj, Svierik; sje, Sverji; sju, Sverje; sma, Sveerje or ; yi, שוועדן, Shvedn; rmu, Svedikko; rmf, Sveittiko. formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic country and the List of European countries by area, fifth-largest country in Europe. The Capital city, capital and largest city is Stockholm. Sweden has a population of 10.5 million, and a low population density of ; around 87% of Swedes reside in urban areas in the central and southern half of the country. Sweden’s urban areas together cover 1.5% of its land area. Because the country is so long, ranging from 55th parallel north, 55°N to 69th parallel north, 69°N, the climate of Sweden is diverse. Sweden has been inhabited since Prehistoric Sweden, prehistoric times, . T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STDMA
Self-organized time-division multiple access (STDMA) is a channel access method designed by Håkan Lans, based on time-division multiplexing. The term "self-organized" describes the manner in which time slots are assigned to users. Time-division multiple access (TDMA) divides a channel into frames, which furthermore are subdivided into a vast number of time slots. Users transmit in rapid succession, one after the other, each using their own time slot. One of the drawbacks of TDMA is that it requires a central station for slot assignment and time synchronisation. STDMA proposes for assigning slots without the involvement of a central station. Time synchronisation is usually taken care of using Coordinated Universal Time (UTC). STDMA is in use by the Automatic Identification System (AIS), a standard marine short-range coastal tracking system, and is the base of the International Civil Aviation Organization VHF Data Link Mode 4. While the method was patented, a US patent ex-parte r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-shift Keying
Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave). The modulation is accomplished by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth communication. Any digital modulation scheme uses a finite number of distinct signals to represent digital data. PSK uses a finite number of phases, each assigned a unique pattern of binary digits. Usually, each phase encodes an equal number of bits. Each pattern of bits forms the symbol that is represented by the particular phase. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the phase of the received signal and maps it back to the symbol it represents, thus recovering the original data. This requires the receiver to be able to compare the phase of the received signal to a reference signal such a system is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-Level Data Link Control
High-Level Data Link Control (HDLC) is a bit-oriented code-transparent synchronous data link layer protocol developed by the International Organization for Standardization (ISO). The standard for HDLC is ISO/IEC 13239:2002. HDLC provides both connection-oriented and connectionless service. HDLC can be used for point-to-multipoint connections via the original master-slave modes Normal Response Mode (NRM) and Asynchronous Response Mode (ARM), but they are now rarely used; it is now used almost exclusively to connect one device to another, using ''Asynchronous Balanced Mode'' (ABM). History HDLC is based on IBM's SDLC protocol, which is the layer 2 protocol for IBM's Systems Network Architecture (SNA). It was extended and standardized by the ITU as LAP (Link Access Procedure), while ANSI named their essentially identical version ADCCP. The HDLC specification does not specify the full semantics of the frame fields. This allows other fully compliant standards to be derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeronautical Mobile (R) Service
Aeronautical mobile (R) service (short: AM(R)S; | also: ''aeronautical mobile radiocommunication (R) service'') is – according to ''Article 1.33'' of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as ''«An aeronautical mobile service reserved for communications relating to safety and regularity of flight, primarily along national or international civil air routes.»'' This service is a so-called safety-of-life service, must be protected for Interferences, and is essential part of air traffic control. ;See also: Classification This ''radiocommunication service'' is classified in accordance with ''ITU Radio Regulations'' (article 1) as follows: Mobile service (article 1.24) *Aeronautical mobile service (article 1.32) **Aeronautical mobile (R)° service (article 1.33) ** Aeronautical mobile (OR)°° (article 1.34) **Aeronautical mobile-satellite service (article 1.35) *** Aeronautical mobile-satellite (R)° service (article 1.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
