Emergency communication

SOS is a Morse code distress signal (), used internationally, originally established for maritime use. In formal notation SOS is written with an overscore line (), to indicate that the Morse code equivalents for the individual letters of "SOS" are transmitted as an unbroken sequence of three dots / three dashes / three dots, with no spaces between the letters. In International Morse Code three dots form the letter "S" and three dashes make the letter "O", so "S O S" became a common way to remember the order of the dots and dashes. IWB, VZE, 3B, and V7 form equivalent sequences, but t

Mayday is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.

type of mobile phone

thumb|upright=1.35|Illumination flares being used during military training exercises thumb|upright=1.35|Flares being fired from a ship during a fleet review

2013 film directed by Brad Anderson

shooting attack in Hanau, Germany

distress radiobeacon, a tracking transmitter that is triggered during an accident

child abduction alert system

Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by government agencies, emergency services, (police forces, fire departments, ambulance) for public safety networks, rail transport staff for train radios, transport services and the military. TETRA is the European version of trunked radio, similar to Project 25.

form of communication

Worldwide emergency communication system for ships at sea

internationally recognized means for obtaining help

method of sending messages to multiple mobile telephone users in a defined area at the same time

ID sent in digital form over a radio frequency to uniquely identify a ship

CQD (transmitted in Morse code as ) is one of the first distress signals adopted for radio use. On 7 January 1904 the Marconi International Marine Communication Company issued "Circular 57", which specified that, for the company's installations, beginning 1 February 1904 "the call to be given by ships in distress or in any way requiring assistance shall be 'C Q D.

international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters

thumb|right|A NAVTEX receiver prints an incoming message thumb|right|NAVTEX message for the Baltic Sea

international satellite-aided search and rescue initiative

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 need help and that the situation is urgent, but for the time being, does not pose an immediate danger to anyone's life or to the vessel itself. This is referred to as a state of "urgency". This is distinct from a mayday call (distress signal), which means that there is imminent danger to life or to the continued viability of the vessel itself. Radioing "pan-pan" informs potential rescuers (including emergency services and other c

international organization

signal made by social animals and people to warn others of danger

emergency location service for mobile phones

call center operated by the local government for emergency phone calls

Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by US public safety officials and in citizens band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code.

transponder intended for emergency use at sea

thumb|Test of the Spanish EU-Alert variant (ES-Alert) in Barcelona in 2023, on an iOS device. EU-Alert is a Public Warning System designed to disseminate emergency alerts to mobile phones based on Cell Broadcast technology, as defined by ETSI standards. National authorities are able to disseminate emergency alerts and warning messages through the system. EU-Alert is a standard designed for interoperability and national implementation may vary. The standards are based on NL-Alert from the Netherlands, which first became operational in 2012.

system of biological or technical nature deployed by an individual or group to inform of a future danger

European missing children hotline number

Fallback service

exclamation given aboard a vessel to indicate that someone has fallen off of the ship

TETRAPOL (short for TErrestrial TRunked RAdio POLice) is a digital professional mobile radio standard, as defined by the TETRAPOL Publicly Available Specification (PAS), used by professional user groups such as public safety, military, industry and transportation organizations throughout the world. Airbus Defence and Space is the main supplier of this technology.

alarm system designed to signal the presence of a hazard requiring urgent attention and to summon emergency medical personnel

Emergency codes typically announced over a hospital's public address system to prompt staff action and inform faculty of the event occuring

maritime radio frequency at 500 kHz

radio frequency on the marine VHF radio band

radio frequency reserved for aeronautical emergencies

communication system used for emergency coordination, often made up of both input devices, sensors, and communication devices, typically capable of both initiating and receiving information among multiple parties

radio frequency designated for emergency communication

Security alert system for ships

instrument used to alert the public in cases of disturbing disappearances of children

collection of flaghoist signals used by the Russian Navy

organization

Sécurité (; French: sécurité) (often repeated thrice, "Sécurité, sécurité, sécurité") is a procedure word used in the maritime radio service that warns the crew that the following message is important safety information. The most common use of this is by coast radio stations before the broadcast of navigational warnings and meteorological information.

MeshCore is an open-source mesh networking protocol and software platform designed for off-grid, low-power text communication using LoRa (Long Range) radio technology. The system enables decentralized, multi-hop wireless messaging without reliance on cellular networks or internet infrastructure.