In telephony, ringdown is a method of signaling an operator in which telephone ringing current is sent over the line to operate a lamp or cause the operation of a self-locking relay known as a drop.
911, sometimes written 9-1-1, is an emergency telephone number for Argentina, Canada, the Dominican Republic, Fiji, Jordan, Iraq, Mexico, Pakistan, Maldives, Palau, Panama, the Philippines, Sint Maarten, the United States, and Uruguay, as well as the North American Numbering Plan (NANP), one of eight N11 codes. Like other emergency numbers, dialing 911 for whatever purpose is a crime in most jurisdictions. Penalties for abuse or misuse of 911 can range from probation or community service to fines and jail time. Offenders can also be ordered to undergo counseling and have their use of telephones restricted or suspended for a period of time as a condition of probation.
Enhanced 911 is a system used in North America to automatically provide the caller's location to 911 dispatchers. 911 is the universal emergency telephone number in the region. In the European Union, a similar system exists known as E112 and known as eCall when called by a vehicle.
An emergency telephone number is a number that allows a caller to contact local emergency services for assistance. The emergency number differs from country to country; it is typically a three-digit number so that it can be easily remembered and dialed quickly. Some countries have a different emergency number for each of the different emergency services; these often differ only by the last digit.
999 is an official emergency telephone number in a number of countries which allows the caller to contact emergency services for emergency assistance. Countries and territories using the number include Bahrain, Bangladesh, Botswana, Cook Island, Eswatini, Ghana, Guernsey, Hong Kong, the Republic of Ireland, the Isle of Man, Jersey, Kenya, Macau, Malaysia, Mauritius, Niue, Poland, Qatar, Sudan, Saudi Arabia, Singapore, Trinidad and Tobago, Seychelles, Uganda, the United Arab Emirates, the United Kingdom, and Zimbabwe.
A pager, also known as a beeper or bleeper, is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknowledge, reply to, and originate messages using an internal transmitter.
A radiotelephone, abbreviated RT, is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to radiotelegraphy, which is radio transmission of telegrams (messages), or television, transmission of moving pictures and sound. The term is related to radio broadcasting, which transmit audio one way to listeners. Radiotelephony refers specifically to two-way radio systems for bidirectional person-to-person voice communication between separated users, such as CB radio or marine radio. In spite of the name, radiotelephony systems are not necessarily connected to or have anything to do with the telephone network, and in some radio services, including GMRS, interconnection is prohibited.
Operator assistance refers to service provided by a telephone operator to the calling party of a telephone call. This can include telephone calls made from pay phones, calls placed station-to-station, person-to-person, or collect, third-number calls, calls billed to credit cards, and certain international calls which cannot be dialed directly. The telephone operator may also be able to assist with determining what kind of technical difficulties are occurring on a phone line, to verify whether a line is busy, or left off the hook, or to break in on a live call to ask the caller to clear the line for an incoming call. The latter service is often utilized by emergency police. In addition, operators are often a first point of contact for the elderly wanting information on the current date and time.
A call box or callbox is a box, usually metal, containing a special-purpose direct line telephone or other telecommunications device which has been used by various industries and institutions as a way for employees or clients at a remote location to contact a central dispatch office.
Base station is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service."
A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells, each served by at least one fixed-location transceiver. These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content via radio waves. Each cell's coverage area is determined by factors such as the power of the transceiver, the terrain, and the frequency band being used. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell.
Mobile telephony is the provision of wireless telephone services to mobile phones, distinguishing it from fixed-location telephony provided via landline phones. Traditionally, telephony specifically refers to voice communication, though the distinction has become less clear with the integration of additional features such as text messaging and data services.
An intercom, also called an intercommunication device, intercommunicator, or interphone, is a stand-alone voice communications system for use within a building, small collection of buildings or portably within a small coverage area, which functions independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles, but can also be detachable and portable. Intercoms can incorporate connections to public address loudspeaker systems, walkie talkies, telephones, and other intercom systems. Some intercom systems incorporate control of devices such as signal lights and door latches.
000 Emergency, also known as Triple Zero or Triple 0, and sometimes stylised Triple Zero (000), is the primary national emergency telephone number in Australia and Australian External Territories. The Emergency Call Service is operated by Telstra, and overseen by the Australian Communications and Media Authority (ACMA), and is intended only for use in life-threatening or time-critical emergencies.
A reverse telephone directory is a collection of telephone numbers and associated customer details. However, unlike a standard telephone directory, where the user uses customer's details in order to retrieve the telephone number of that person or business, a reverse telephone directory allows users to search by a telephone service number in order to retrieve the customer details for that service.
A party line is a local loop telephone circuit that is shared by multiple telephone service subscribers.
A bat phone or batphone, in popular jargon, is a private telephone number for important telephone calls handled at high priority. The term is also used to describe the use of more than one mobile phone, with the "bat phone" reserved for a specific purpose. The name Bat-Phone was popularized by the Batman television series starting in 1966, when it was depicted as a red phone that Commissioner Gordon used to summon the superhero Batman in emergencies, and as the red phone mounted inside the Batmobile, the car driven by Batman. Technology journalists have also used "Bat Phone" to describe devices that are novel in appearance, or have a connection to the Batman franchise.
Illegal taxicabs, sometimes known as pirate taxis, gypsy cabs, or jitney cabs, are taxicabs and other for-hire vehicles that are not duly licensed or permitted by the jurisdiction in which they operate. Most major cities worldwide require taxicabs to be licensed, safety-inspected, insured as for-hire vehicles, and to use taximeters, and there may also be requirements that the taxi driver be registered or accredited. However, many unlicensed cabs are in operation. Illegal cabs may be marked taxi vehicles, and others are personal vehicles used by an individual to offer unauthorized taxi-like services. Illegal cabs are prevalent in cities with medallion systems, which restrict the number of legal cabs in operation. Since their introduction in 2009, vehicles affiliated with ridesharing companies have been classified as illegal taxicabs in some jurisdictions.
A telephone number is a sequence of digits assigned to a landline telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN), or other public and private networks. Modern smart phones have added a built-in layer of abstraction whereby individuals or businesses are saved into a contacts application and the numbers no longer have to be written down or memorized.
Telephone interpreting connects human interpreters via telephone to individuals who wish to speak to each other but do not share a common language. The telephone interpreter converts the spoken language from one language to another, enabling listeners and speakers to understand each other. Interpretation over the telephone most often takes place in consecutive mode, which means that the interpreter waits until the speaker finishes an utterance before rendering the interpretation into the other language. As the use of the telephonic modality is increasing it is allowing users to access an interpreter immediately, regardless of time and location.
