In
broadcasting
Broadcasting is the distribution (business), distribution of sound, audio or video content to a dispersed audience via any electronic medium (communication), mass communications medium, but typically one using the electromagnetic spectrum (radio ...
and
radio communications
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...
, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a
unique identifier
A unique identifier (UID) is an identifier that is guaranteed to be unique among all identifiers used for those objects and for a specific purpose. The concept was formalized early in the development of computer science and information systems. ...
for a
transmitter station
A transmitter station or transmission facility is an installation used for transmitting radio frequency signals for wireless communication, broadcasting, microwave link, mobile telephone or other purposes.
Choice of location
The location may b ...
. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even
cryptographically
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adv ...
encoded
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...
to disguise a station's identity.
The use of call signs as unique identifiers dates to the landline
railroad
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
system. Because there was only one
telegraph line
Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems ...
linking all
railroad stations
A train station, railway station, railroad station or depot is a railway facility where trains stop to load or unload passengers, freight or both. It generally consists of at least one platform, one track and a station building providing such ...
, there needed to be a way to
address
An address is a collection of information, presented in a mostly fixed format, used to give the location of a building, apartment, or other structure or a plot of land, generally using political boundaries and street names as references, along w ...
each one when sending a
telegram
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
. In order to save time, two-letter identifiers were adopted for this purpose. This pattern continued in
radiotelegraph
Wireless telegraphy or radiotelegraphy is transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies for t ...
operation;
radio companies initially assigned two-letter identifiers to
coastal stations and
stations onboard ships at sea. These were not globally unique, so a one-letter company identifier (for instance, 'M' and two letters as a
Marconi station
A list of early wireless telegraphy radio stations of the Marconi Wireless Telegraph Co. Guglielmo Marconi developed the first practical radio transmitters and receivers between 1895 and 1901. His company, the Marconi Wireless Telegraph ...
) was later added. By 1912, the need to quickly identify stations operated by multiple companies in multiple nations required an
international standard
international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International Or ...
; an
ITU prefix would be used to identify a country, and the rest of the call sign an individual station in that country.
Transportation
Maritime
Merchant and naval vessels are assigned call signs by their national licensing authorities. In the case of states such as
Liberia
Liberia (), officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to its north, Ivory Coast to its east, and the Atlantic Ocean ...
or
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...
, which are
flags of convenience
Flag of convenience (FOC) is a business practice whereby a ship's owners register a merchant ship in a ship register of a country other than that of the ship's owners, and the ship flies the civil ensign of that country, called the flag state ...
for ship registration, call signs for larger vessels consist of the national prefix plus three letters (for example, 3LXY, and sometimes followed by a number, i.e. 3LXY2). United States merchant vessels are given call signs beginning with the letters "W" or "K" while US naval ships are assigned call signs beginning with "N". Originally, both ships and broadcast stations were assigned call signs in this series consisting of three or four letters. Ships equipped with Morse code radiotelegraphy, or life boat radio sets, Aviation ground stations, broadcast stations were given four letter call signs. Maritime coast stations on high frequency (both radiotelegraphy and radiotelephony) were assigned three letter call signs. As demand for both
marine radio
Marine VHF radio is a worldwide system of two way radio transceivers on ships and watercraft used for bidirectional voice communication from ship-to-ship, ship-to-shore (for example with harbormasters), and in certain circumstances ship-to-a ...
and broadcast call signs grew, gradually American-flagged vessels with radiotelephony only were given longer call signs with mixed letters and numbers.
Leisure craft with VHF radios may not be assigned call signs, in which case the name of the vessel is used instead. Ships in the US still wishing to have a radio license are under
FCC
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdiction ...
class SA: "Ship recreational or voluntarily equipped." Those calls follow the land mobile format of the initial letter K or W followed by 1 or 2 letters followed by 3 or 4 numbers (such as KX0983 or WXX0029).
U.S. Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mul ...
small boats have a number that is shown on both bows (i.e. port and starboard) in which the first two digits indicate the nominal length of the boat in feet. For example, Coast Guard 47021 refers to the 21st in the series of 47-foot motor lifeboats. The call sign might be abbreviated to the final two or three numbers during operations, for example: ''Coast Guard zero two one''.
Aviation
Originally aviation mobile stations (aircraft) equipped with radiotelegraphy were assigned five-letter call signs (e.g. KHAAQ). Land stations in aviation were assigned four-letter call signs (e.g. WEAL – Eastern Air Lines, NYC.) These call signs were phased out in the 1960s when
flight radio officer
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
s (FRO) were no longer required on international flights. The Russian Federation kept FROs for the Moscow-Havana run until around 2000.
Currently, all signs in
aviation
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot air ...
are derived from several different policies, depending upon the type of flight operation and whether or not the caller is in an aircraft or at a ground facility. In most countries, unscheduled
general aviation
General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services ...
flights identify themselves using the call sign corresponding to the
aircraft's registration number (also called ''N-number'' in the U.S., or ''tail number''). In this case, the call sign is spoken using the
International Civil Aviation Organization
The International Civil Aviation Organization (ICAO, ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sc ...
(ICAO)
phonetic alphabet. Aircraft registration numbers internationally follow the pattern of a country prefix, followed by a unique identifier made up of letters and numbers. For example, an aircraft registered as ''N978CP'' conducting a
general aviation
General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services ...
flight would use the call sign ''November-niner-seven-eight-Charlie-Papa''. However, in the United States a pilot of an aircraft would normally omit saying ''November'', and instead use the name of the aircraft manufacturer or the specific model. At times, general aviation pilots might omit additional preceding numbers and use only the last three numbers and letters. This is especially true at uncontrolled fields (those without control towers) when reporting traffic pattern positions or at towered airports after establishing two-way communication with the tower controller. For example, ''Skyhawk eight-Charlie-Papa, left base''. In commercial aviation, the callsign is usually the ICAO
Flight number
In the aviation industry, a flight number or flight designator is a code for an airline service consisting of two-character airline designator and a 1 to 4 digit number. For example, "BA 98" is a British Airways service from Toronto-Pearson to ...
. For example, ''Delta Airlines Flight 744'' would have the flight number ''DL744'' and the callsign would be ''Delta 744''.
In most countries, the aircraft call sign or "tail number"/"tail letters" (also known as registration marks) are linked to the international radio call sign allocation table and follow a convention that aircraft radio stations (and, by extension, the aircraft itself) receive call signs consisting of five letters. For example, all British
civil aircraft
Civil aviation is one of two major categories of flying, representing all non-military and non-state aviation, both private and commercial. Most of the countries in the world are members of the International Civil Aviation Organization and work ...
have a five-letter registration beginning with the letter G, which can also serve for a call sign. Canadian aircraft have a call sign beginning with C–F or C–G, such as C–FABC.
wing-in-ground-effect vehicle
A ground-effect vehicle (GEV), also called a wing-in-ground-effect (WIG), ground-effect craft, wingship, flarecraft or ekranoplan (russian: экранопла́н – "screenglider"), is a vehicle that is able to move over the surface by gainin ...
s and
hovercraft
A hovercraft, also known as an air-cushion vehicle or ACV, is an amphibious Craft (vehicle), craft capable of travelling over land, water, mud, ice, and other surfaces.
Hovercraft use blowers to produce a large volume of air below the hull ...
in Canada are eligible to receive C–Hxxx call signs, and
ultralight aircraft
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...
receive C-Ixxx call signs. In days gone by, even American aircraft used five letter call signs, such as KH–ABC, but they were replaced prior to World War II by the current American system of civilian aircraft call signs (see below). One exception to the parallelism between registration and call sign is
ultralight
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...
aeroplanes in France, who are not obliged to carry a radio and indeed often don't.
Spaceflight
Radio call signs used for communication in crewed spaceflight are not formalized or regulated to the same degree as for aircraft. The three nations currently launching crewed space missions use different methods to identify the ground and space radio stations; the United States uses either the names given to the space vehicles, or else the project name and mission number. Russia traditionally assigns code names as call signs to individual
cosmonaut
An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member aboard a spacecraft. Although generally r ...
s, more in the manner of
aviator call sign An aviator call sign or aviator callsign is a call sign given to a military pilot, flight officer, and even some enlisted aviators. The call sign is a specialized form of nickname that is used as a substitute for the aviator's given name. It is use ...
s, rather than to the spacecraft.
The only continuity in call signs for spacecraft have been the issuance of "ISS"-suffixed call signs by various countries in the amateur radio service as a citizen of their country has been assigned there. The first amateur radio call sign assigned to the International Space Station was NA1SS by the United States. OR4ISS (Belgium), DP0ISS (Germany), and RS0ISS (Russia) are examples of others, but are not all-inclusive of others also issued.
Broadcasting
![QSL card sent to listener confirming reception of WWV from Maryland - 194007](https://upload.wikimedia.org/wikipedia/commons/3/35/QSL_card_sent_to_listener_confirming_reception_of_WWV_from_Maryland_-_194007.jpg)
Broadcasters are allocated call signs in many countries. While broadcast radio stations will often
brand
A brand is a name, term, design, symbol or any other feature that distinguishes one seller's good or service from those of other sellers. Brands are used in business, marketing, and advertising for recognition and, importantly, to create an ...
themselves with plain-text names, identities such as "
Cool
Cool commonly refers to:
* Cool, a moderately low temperature
* Cool (aesthetic), an aesthetic of attitude, behavior, and style
Cool or COOL may also refer to:
Economics
* Country of origin labelling
* mCOOL - US consumer legislation to enforc ...
FM", "
Rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wales ...
105" or "the ABC network" are not globally unique. Another station in another city or country may (and often will) have a similar brand, and the name of a broadcast station for legal purposes is normally its internationally recognised ITU call sign. Some common conventions are followed in each country.
Broadcast stations in North America generally use call signs in the international series. In the United States of America, they are used for all FCC-licensed transmitters. The first letter generally is ''K'' for stations located west of the
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...
and ''W'' for eastern stations. Historic exceptions in the east include
KYW in Philadelphia and
KDKA in Pittsburgh, while western exceptions include
WJAG
WJAG (780 AM broadcasting, AM, "Newstalk 780") is a radio station broadcasting a Talk radio, News/Talk/Information format. Licensed to Norfolk, Nebraska, United States, the station was initially licensed in 1922 to the Huse Publishing Company, p ...
in
Norfolk, Nebraska
Norfolk ( or ) is a city in Madison County, Nebraska, United States, 113 miles northwest of Omaha and 83 miles west of Sioux City at the intersection of U.S. Routes 81 and 275. The population was 24,210 at the 2010 census, making it the nint ...
, and
WOAI in San Antonio. All new call signs have been four-character for some decades, though there are historical
three-character call letters still in use today, such as
KSL in Salt Lake City,
KOA
KOA (short for Kampgrounds of America) is an American franchise of privately owned campgrounds. Having more than 500 locations across the United States and Canada, it is the world's largest system of privately owned campgrounds. It was founded in ...
in Denver,
WHO
Who or WHO may refer to:
* Who (pronoun), an interrogative or relative pronoun
* Who?, one of the Five Ws in journalism
* World Health Organization
Arts and entertainment Fictional characters
* Who, a creature in the Dr. Seuss book ''Horton Hear ...
in Des Moines,
WWJ and
WJR in Detroit,
WJW-TV
WJW (channel 8) is a television station in Cleveland, Ohio, United States, affiliated with the Fox network. Owned by Nexstar Media Group, WJW maintains studios on Dick Goddard Way (named for the station's late longtime weatherman—previously ...
in
Cleveland
Cleveland ( ), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. ...
,
WBT in Charlotte,
WBZ in Boston,
WSM in Nashville,
WGR
WGR (550 AM) is a commercial radio station licensed to serve Buffalo, New York. Owned by Audacy, Inc., its studios and offices are located on Corporate Parkway in Amherst, and the transmitter site—utilized by WGR and co-owned WWKB—is in Ham ...
in Buffalo,
KFI
KFI (640 AM) is a radio station in Los Angeles, California, owned and operated by iHeartMedia, Inc. It began operations in 1922 and became one of the first high-powered, clear-channel Class A stations. It was the first U.S. station west of Chi ...
,
KNX and
KHJ in Los Angeles, and
WGN,
WLS and
WLS-TV
WLS-TV (channel 7) is a television station in Chicago, Illinois, United States, airing programming from the ABC network. Owned and operated by the network's ABC Owned Television Stations division, the station maintains studios on North State S ...
in Chicago. American radio stations announce their call signs (except for rare cases in which would interfere with the broadcast of very long works of classical or opera music) at the top of each hour, as well as sign-on and sign-off for stations that do not broadcast 24 hours. Beginning in the early 2000s, digital subchannels were assigned a -DT# suffix, where # is the sub channel position (starting with the number 2).
In Canada, the publicly owned
Canadian Broadcasting Corporation
The Canadian Broadcasting Corporation (french: Société Radio-Canada), branded as CBC/Radio-Canada, is a Canadian public broadcaster for both radio and television. It is a federal Crown corporation that receives funding from the government. ...
uses the prefix ''CB''; privately owned commercial broadcast stations use primarily ''CF'' and ''CH'' through ''CK'' prefixes; and four stations licensed to
St. John's by the
Dominion of Newfoundland
Newfoundland was a British dominion in eastern North America, today the modern Canadian province of Newfoundland and Labrador. It was established on 26 September 1907, and confirmed by the Balfour Declaration of 1926 and the Statute of Westmi ...
government retain their original ''VO'' calls. In Mexico,
AM radio
AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transm ...
stations use ''XE'' call signs (such as
XEW-AM
XEW-AM is a radio station in Mexico City, Mexico, broadcasting on the AM frequency of 900 kHz; it is branded as ''W Radio''. XEW-AM serves as the originating station for other "W Radio" stations around Mexico that carry some of its program ...
), while the majority of
FM radio
FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is cap ...
and television stations use ''XH''. Broadcast call signs are normally four or five alpha characters in length, plus the ''-FM'', ''-TV'', or ''-TDT'' suffix where applicable.
In South America call signs have been a traditional way of identifying radio and TV stations. Some stations still broadcast their call signs a few times a day, but this practice is becoming very rare. Argentinian broadcast call signs consist of two or three letters followed by multiple numbers, the second and third letters indicating region. In Brazil, radio and TV stations are identified by a ZY, a third letter and three numbers. ''ZYA'' and ''ZYB'' are allocated to television stations, ''ZYI'', ''ZYJ'', ''ZYL'' and ''ZYK'' designate AM stations, ''ZYG'' is used for
shortwave
Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 me ...
stations, ''ZYC'', ''ZYD'', ''ZYM'' and ''ZYU'' are given to FM stations.
In Australia, broadcast call signs are optional, but are allocated by the
Australian Communications and Media Authority
The Australian Communications and Media Authority (ACMA) is an Australian government statutory authority within the Communications portfolio. ACMA was formed on 1 July 2005 with the merger of the Australian Broadcasting Authority and the Austr ...
and are unique for each broadcast station.
Most European and Asian countries do not use call signs to identify broadcast stations, but Japan, South Korea, Indonesia, the Philippines and Taiwan do have call sign systems. Spanish broadcasters used call signs consisting of ''E'' followed by two letters and up to three digits until the late 1970s. Portugal had a similar system, their callsigns beginning with ''C''; these also ceased to be used in the 1970s. Britain has no call signs in the American sense, but allows broadcast stations to choose their own
trade mark
A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from others. ...
call sign up to six words in length.
Amateur radio
Amateur radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...
call signs are in the international series and normally consist of a one or two character prefix, a digit (which may be used to denote a geographical area, class of license, or identify a licensee as a visitor or temporary resident), and a 1-, 2-, or 3-letter suffix. In Australia, call signs are structured with a two letter prefix, a digit (which identifies geographical area), and a 2, 3 or 4 letter suffix. This suffix may be followed by a further suffix, or personal identifier, such as /P (portable), /M (mobile), /AM (aeronautical mobile) or /MM (maritime mobile). The number following the prefix is normally a single number (0 to 9). Some prefixes, such as Djibouti's (J2), consist of a letter followed by a number. Hence, in the hypothetical Djibouti call sign, J29DBA, the prefix is ''J2'', the number is ''9'', and the suffix is ''DBA''. Others may start with a number followed by a letter, for example, Jamaican call signs begin with 6Y.
When operating with reciprocal agreements under the jurisdiction of a foreign government, an identifying station pre-pends the call sign with the country prefix and number of the country/territory from which the operation is occurring. For example, W4/G3ABC would denote a licensed amateur from the United Kingdom who is operating in the fourth district of the United States. There are exceptions; in the case of U.S./Canadian reciprocal operations, the country/territory identifier is, instead, appended to the call sign; e.g., W1AW/VE4, or VE3XYZ/W1.
Special call signs are issued in the amateur radio service either for special purposes, VIPs, or for temporary use to commemorate special events. Examples include ''VO1S'' (''VO1'' as a
Dominion of Newfoundland
Newfoundland was a British dominion in eastern North America, today the modern Canadian province of Newfoundland and Labrador. It was established on 26 September 1907, and confirmed by the Balfour Declaration of 1926 and the Statute of Westmi ...
call sign prefix, ''S'' to commemorate
Marconi's first trans-Atlantic message, a single-character
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
''S'' sent from
Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
, England to Signal Hill,
St. John's in 1901) and GB90MGY (''GB'' as a Great Britain call sign prefix, ''90'' and ''MGY'' to commemorate the 90th anniversary of historic 1912 radio
distress call
A distress signal, also known as a distress call, is an internationally recognized means for obtaining help. Distress signals are communicated by transmitting radio signals, displaying a visually observable item or illumination, or making a soun ...
s from ''MGY'', the
Marconi station
A list of early wireless telegraphy radio stations of the Marconi Wireless Telegraph Co. Guglielmo Marconi developed the first practical radio transmitters and receivers between 1895 and 1901. His company, the Marconi Wireless Telegraph ...
aboard the famed
White Star luxury liner
RMS ''Titanic'').
The late
King Hussein
Hussein bin Talal ( ar, الحسين بن طلال, ''Al-Ḥusayn ibn Ṭalāl''; 14 November 1935 – 7 February 1999) was King of Jordan from 11 August 1952 until his death in 1999. As a member of the Hashemite dynasty, the royal family of ...
of
Jordan
Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...
was issued a special amateur license number, JY1, which would have been the shortest possible call sign issued by the Hashemite Kingdom of Jordan.
When identifying a station by voice, the call sign may be given by simply stating the letters and numbers, or using a
phonetic alphabet. Some countries mandate the use of the phonetic alphabet for identification.
Military call signs
In wartime, monitoring an adversary's communications can be a valuable form of intelligence. Consistent call signs can aid in this monitoring, so in wartime, military units often employ
tactical call signs and sometimes change them at regular intervals. In peacetime, some military stations will use fixed call signs in the international series.
The
United States Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...
uses fixed station call signs which begin with ''W'', such as WAR, used by U.S. Army Headquarters. Fixed call signs for the
United States Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...
stations begin with ''A'', such as AIR, used by USAF Headquarters. The
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
,
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combi ...
, and
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mult ...
use a mixture of tactical call signs and international call signs beginning with the letter ''N''.
In the
British military
The British Armed Forces, also known as His Majesty's Armed Forces, are the military forces responsible for the defence of the United Kingdom, its Overseas Territories and the Crown Dependencies. They also promote the UK's wider interests, su ...
, tactical voice communications use a system of call signs of the form ''letter-digit-digit''. Within a standard infantry battalion, these characters represent companies, platoons and sections respectively, so that 3 Section, 1 Platoon of F Company might be F13. In addition, a suffix following the initial call sign can denote a specific individual or grouping within the designated call sign, so F13C would be the Charlie
fire team
A fireteam or fire team is a small military sub-subunit of infantry designed to optimize "bounding overwatch" and "fire and movement" military doctrine, tactical doctrine in combat. Depending on mission requirements, a typical fireteam consist ...
. Unused suffixes can be used for other call signs that do not fall into the standard call sign matrix, for example the unused 33A call sign is used to refer to the
company sergeant major.
Transmitters requiring no call signs
No call signs are issued to transmitters of the long-range navigation systems (
Decca Decca may refer to:
Music
* Decca Records or Decca Music Group, a record label
* Decca Gold, a classical music record label owned by Universal Music Group
* Decca Broadway, a musical theater record label
* Decca Studios, a recording facility in W ...
,
Alpha
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
,
Omega
Omega (; capital: Ω, lowercase: ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and final letter in the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The wo ...
), or transmitters on frequencies
below 10 kHz, because frequencies below 10 kHz are not subject to international regulations. In addition, in some countries lawful unlicensed low-power personal and broadcast radio signals (
Citizen's Band
Citizens band radio (also known as CB radio), used in many countries, is a land mobile radio system, a system allowing short-distance person-to-many persons bidirectional voice communication among individuals, using two way radios operating on ...
(CB),
Part 15
Code of Federal Regulations, 'Title 47, Part 15(47 CFR 15) is an oft-quoted part of Federal Communications Commission (FCC) rules and regulations regarding unlicensed transmissions. It is a part of Title 47 of the Code of Federal Regulations ...
or
ISM band
The ISM radio bands are portions of the radio spectrum reserved internationally for industrial, scientific and medical (ISM) purposes, excluding applications in telecommunications.
Examples of applications for the use of radio frequency (RF) ener ...
s) are permitted; an international call sign is not issued to such stations due to their unlicensed nature. Also, wireless network routers or mobile devices and computers using
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
are unlicensed and do not have call signs. On some personal radio services, such as CB, it is considered a matter of etiquette to create one's own call sign, which is called a
handle
A handle is a part of, or attachment to, an object that allows it to be grasped and manipulated by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tra ...
(or trail name). Some
wireless networking
A wireless network is a computer network that uses wireless data connections between network nodes.
Wireless networking is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing c ...
protocols also allow
SSIDs or
MAC address
A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking techno ...
es to be set as identifiers, but with no guarantee that this label will remain unique. Many
mobile telephony
Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the li ...
systems identify
base transceiver stations by implementing
cell ID
A GSM Cell ID (CID) is a generally unique number used to identify each base transceiver station (BTS) or sector of a BTS within a location area code (LAC) if not within a GSM network.
In some cases the first or last digit of CID represents cells ...
and mobile stations (e.g., phones) by requiring them to authenticate using
international mobile subscriber identity
The international mobile subscriber identity (IMSI) is a number that uniquely identifies every user of a cellular network. It is stored as a field and is sent by the mobile device to the network. It is also used for acquiring other details of th ...
(IMSI).
International regulations no longer require a call sign for broadcast stations; however, they are still required for broadcasters in many countries, including the United States. Mobile phone services do not use call signs on-air because the phones and their users are not licensed, instead the cell operator is the one holding the license. However, the U.S. still assigns a call sign to each mobile-phone spectrum license.
In the United States, ''voluntary ships'' operating domestically are not required to have a call sign or license to operate
VHF radios,
radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
or an
EPIRB
An Emergency Position-Indicating Radio Beacon (EPIRB) is a type of emergency locator beacon for commercial and recreational boats, a portable, battery-powered radio transmitter used in emergencies to locate boaters in distress and in need of i ...
. Voluntary ships (mostly pleasure and recreational) are not required to have a radio. However, ships which are required to have radio equipment (most large commercial vessels) are issued a call sign.
Callbooks
![Callbook 1919 excerpt](https://upload.wikimedia.org/wikipedia/commons/e/e4/Callbook_1919_excerpt.jpg)
A directory of radio station call signs is called a callbook. Callbooks were originally bound books that resembled a
telephone directory
A telephone directory, commonly called a telephone book, telephone address book, phonebook, or the white and yellow pages, is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization tha ...
and contained the name and addressees of licensed radio stations in a given jurisdiction (country). Modern Electrics published the first callbook in the United States in 1909.
Today, the primary purpose of a callbook is to allow amateur radio operators to send a confirmation post card, called a
QSL card
A QSL card is a written confirmation of either a two-way radiocommunication between two amateur radio or citizens band stations; a one-way reception of a signal from an AM radio, FM radio, television or shortwave broadcasting station; or the re ...
to an operator with whom they have communicated via radio. Callbooks have evolved to include on-line databases that are accessible via the Internet to instantly obtain the address of another amateur radio operator and their QSL Managers. The most well known and used on-line QSL databases include QRZ.COM, IK3QAR, HamCall, F6CYV, DXInfo, OZ7C and QSLInfo.
See also
*
ITU prefix
*
NATO phonetic alphabet
The (International) 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 spellin ...
*
Pan-pan
The radiotelephony message PAN-PAN is the international standard urgency signal that someone aboard a boat, ship, aircraft, or other vehicle uses to declare that they have a situation that is urgent, but for the time being, does not pose an immed ...
*
Procedure word
Procedure words (abbreviated to prowords) are words or phrases limited to radio telephone procedure used to facilitate communication by conveying information in a condensed standard verbal format. Prowords are voice versions of the much older pro ...
*
Pseudonym
A pseudonym (; ) or alias () is a fictitious name that a person or group assumes for a particular purpose, which differs from their original or true name (orthonym). This also differs from a new name that entirely or legally replaces an individua ...
References
Further reading
* United States Federal Aviation Administration, ''Aeronautical Information Manual, Official Guide to Basic Flight Information and ATC Procedures,'' 2004
Chapter 4, Section 2
External links
*
ttp://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp FCC amateur radio operator searchAmateur Call PrefixesInternet Radio Uniform Callsign (IRUC) programFCCData.orga database of international telecommunications administrations, searchable by callsign, covering AM, FM, DAB and TV in the United States, Canada, Mexico, the United Kingdom, Ireland, Japan and Australia
Military Call Sign ListRadio-Locatora search engine of all of the radio stations in the world with websites, searchable by location, frequency, and call sign
-
Industry Canada
Innovation, Science and Economic Development Canada (ISED; french: Innovation, Sciences et Développement économique Canada; french: ISDE, label=none)''Innovation, Science and Economic Development Canada'' is the applied title under the Federal I ...
Call Letter Origins
{{Authority control
Broadcast law
Telecommunications law