The International Radiotelephony Spelling Alphabet or simply the Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear-code words for communicating the letters of the Roman alphabet. Technically a radiotelephonic spelling alphabet, it goes by various names, including NATO spelling alphabet, ICAO phonetic alphabet, and ICAO spelling alphabet. The ITU phonetic alphabet and figure code is a rarely used variant that differs in the code words for digits.
The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an operating signal initially developed for commercial radiotelegraph communication and later adopted by other radio services, especially amateur radio. To distinguish the use of a Q-code transmitted as a question from the same Q-code transmitted as a statement, operators either prefixed it with the military network question marker "INT" or suffixed it with the standard Morse question mark UD.
Mayday is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.
The ITU Radio Regulations (RR) is a basic document of the International Telecommunication Union (ITU) that regulates on law of nations scale radiocommunication services and the utilisation of radio frequencies. It is the supplementation to the ITU Constitution and Convention and in line with the ITU International Telecommunication Regulations (ITR). The ITU RR comprise and regulate the part of the allocated electromagnetic spectrum from 9 kHz to 300 GHz.
The Aeronautical Fixed Telecommunications Network (AFTN) is a worldwide system of aeronautical fixed circuits provided, as part of the Aeronautical Fixed Service, for the exchange of messages and/or digital data between aeronautical fixed stations having the same or compatible communications characteristics. AFTN comprises aviation entities including: ANS providers, aviation service providers, airport authorities and government agencies, to name a few. It exchanges vital information for aircraft operations such as distress messages, urgency messages, flight safety messages, meteorological messages, flight regularity messages and aeronautical administrative messages.
Airband or aircraft band is the name for a group of frequencies in the VHF radio spectrum allocated to radio communication in civil aviation, sometimes also referred to as VHF, or phonetically as "Victor". Different sections of the band are used for radionavigational aids and air traffic control.
The airline teletype system uses teleprinters, which are electro-mechanical typewriters that can communicate typed messages from point to point through simple electric communications channels, often just pairs of wires. The most modern form of these devices are fully electronic and use a screen, instead of a printer.
The European Organisation for the Safety of Air Navigation, commonly known as Eurocontrol, is an international organisation working to achieve safe and seamless air traffic management across Europe. Founded in 1963, Eurocontrol currently has 41 member states with headquarters in Brussels, Belgium. It has several local sites as well, including an Innovation Hub in Brétigny-sur-Orge, France, the Aviation Learning Centre (ALC) in Luxembourg, and the Maastricht Upper Area Control Centre (MUAC) in Maastricht, the Netherlands. The organisation employs approximately two thousand people, and operates with an annual budget in excess of half a billion euros.
Fixed-satellite service is – according to article 1.21 of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as A radiocommunication service between earth stations at given positions, when one or more satellites are used; the given position may be a specified fixed point or any fixed point within specified areas; in some cases this service includes satellite-to-satellite links, which may also be operated in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services.
Aeronautical Message Handling System (AMHS) or Air Traffic Services Message Handling System (ATSMHS) is a standard for aeronautical ground-ground communications based on X.400 profiles. It has been defined by the ICAO.
Spectrum management is the process of regulating the use of radio frequencies to promote efficient use and gain a net social benefit. The term radio spectrum typically refers to the full frequency range from 1 Hz to 3000 GHz that may be used for wireless communication. Increasing demand for services such as mobile telephones and many others has required changes in the philosophy of spectrum management. Demand for wireless broadband has soared due to technological innovation, such as 3G and 4G mobile services, and the rapid expansion of wireless internet services.
A spelling alphabet is a set of words used to represent the letters of an alphabet in oral communication, especially over a two-way radio or telephone. The words chosen to represent the letters sound sufficiently different from each other to clearly differentiate them. This avoids any confusion that could easily otherwise result from the names of letters that sound similar, except for some small difference easily missed or easily degraded by the imperfect sound quality of the apparatus. For example, in the Latin alphabet, the letters B, P, and D sound similar and could easily be confused, but the words "bravo", "papa" and "delta" sound completely different, making confusion unlikely.
The Aeronautical Information Service, or AIS is a service established in support of international civil aviation, whose objective is to ensure the flow of information necessary for the safety, regularity, and efficiency of international air navigation.
The VHF Data Link or VHF Digital Link (VDL) is a means of sending information between aircraft and ground stations. 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).
One way of outlining the subject of radio science is listing the topics associated with it by authoritative bodies.
Inter-satellite service, also known as inter-satellite radiocommunication service, as defined by Article 1.22 of the International Telecommunication Union's (ITU) Radio Regulations (RR), is a radiocommunication service providing links between artificial satellites.
Safety service is – according to Article 1.59 of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as «A radiocommunication service used permanently or temporarily for the safeguarding of human life and property.»
A feeder link is – according to Article 1.115 of the International Telecommunication Union´s (ITU) ITU Radio Regulations (RR) – defined as:
A radio link from an earth station at a given location to a space station, or vice versa, conveying information for a space radiocommunication service other than for the fixed-satellite service. The given location may be at a specified fixed point, or at any fixed point within specified areas.
Aeronautical mobile service is a form of aviation communication conducted through radio. The ITU Radio Regulations divide AMS into communication used for civil air route flights (R) and off-route flights (OR). Aeronautical mobile (R) service is a so-called safety-of-life service, must be protected for interferences, and is an essential part of air traffic control. Communication occurs between radio stations onboard aircraft, termed aircraft stations, and terrestrial stations that are sometimes termed "aeronautical stations". Communication can also occur between aircraft. AMS is commonly used in air traffic control.
Ship earth station is – according to Article 1.78 of the International Telecommunication Union's (ITU) ITU Radio Regulations (RR) – defined as "A mobile earth station in the maritime mobile-satellite service located on board ship."
