49 relations: Amateur radio, Asterisk, Autovon, Bell 202 modem, Bell System, Broadcasting, Cable television, Call-progress tone, Caller ID, Calling party, Communication protocol, Digital signal processing, Dual-tone multi-frequency signaling, Frequency-shift keying, Goertzel algorithm, Hertz, In-band signaling, ITU-T, Keypad, Landline, Local loop, Long-distance calling, Magnetic stripe card, Multi-frequency signaling, Nortel, Number sign, Numerical digit, Ogg, Payphone, Precise Tone Plan, Pulse dialing, Pure tone, Push-button telephone, R2 signalling, Rotary dial, Selective calling, Signaling (telecommunications), Signalling System No. 7, Sine wave, Special information tones, Subscriber trunk dialling, Switchboard operator, Telephone, Telephone call, Telephone exchange, Telephone keypad, United States Armed Forces, Vertical service code, VHS.
Amateur radio, also known as ham radio, describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication.
An asterisk (*); from Late Latin asteriscus, from Ancient Greek ἀστερίσκος, asteriskos, "little star") is a typographical symbol or glyph. It is so called because it resembles a conventional image of a star. Computer scientists and mathematicians often vocalize it as star (as, for example, in the A* search algorithm or C*-algebra). In English, an asterisk is usually five-pointed in sans-serif typefaces, six-pointed in serif typefaces, and six- or eight-pointed when handwritten. It is often used to censor offensive words, and on the Internet, to indicate a correction to a previous message. The asterisk is derived from the need of the printers of family trees in feudal times for a symbol to indicate date of birth. The original shape was seven-armed, each arm like a teardrop shooting from the center. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication.
The Automatic Voice Network (AUTOVON, military designation 490-L), Aviation Week & Space Technology, September 23, 1963, v. 79, no.
The Bell 202 modem was an early (1976) modem standard developed by the Bell System.
The Bell System was the system of companies, led by the Bell Telephone Company and later by AT&T, which provided telephone services to much of the United States and Canada from 1877 to 1984, at various times as a monopoly.
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model.
Cable television is a system of delivering television programming to paying subscribers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fiber-optic cables.
In telephony, call progress tones are audible tones that provide an indication of the status of a telephone call to the user.
Caller ID (caller identification, CID), also called calling line identification (CLID), Calling Line Identification (CLI), calling number delivery (CND), calling number identification (CNID), calling line identification presentation (CLIP), or call display, is a telephone service, available in analog and digital telephone systems, including VoIP, that transmits a caller's telephone number to the called party's telephone equipment when the call is being set up.
The calling party (in some contexts called the "A-Number") is a person who (or device that) initiates a telephone call.
In telecommunication, a communication protocol is a system of rules that allow two or more entities of a communications system to transmit information via any kind of variation of a physical quantity.
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations.
Dual-tone multi-frequency signaling (DTMF) is an in-band telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal.
The Goertzel algorithm is a technique in digital signal processing (DSP) that provides a means for efficient evaluation of individual terms of the discrete Fourier transform (DFT), thus making it useful in certain practical applications, such as recognition of DTMF tones produced by the buttons pushed on a telephone keypad.
The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second.
In telecommunications, in-band signaling is the sending of control information within the same band or channel used for voice or video.
The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU); it coordinates standards for telecommunications.
A keypad is a set of buttons arranged in a block or "pad" which bear digits, symbols or alphabetical letters.
A landline telephone (also known as land line, land-line, main line, home phone, landline, fixed-line, and wireline) is a phone that uses a metal wire or optical fiber telephone line for transmission as distinguished from a mobile cellular line, which uses radio waves for transmission.
In telephony, the local loop (also referred to as a local tail, subscriber line, or in the aggregate as the last mile) is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the common carrier or telecommunications service provider's network.
In telecommunications, a long-distance call or trunk call is a telephone call made to a location outside a defined local calling area.
A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card.
In telephony, multi-frequency signaling (MF) is a signaling system that was introduced by the Bell System after World War II.
Nortel Networks Corporation, formerly known as Northern Telecom Limited, Northern Electric and sometimes known simply as Nortel, was a multinational telecommunications and data networking equipment manufacturer headquartered in Mississauga, Ontario, Canada.
The symbol # is most commonly known as the number sign, hash, or pound sign.
A numerical digit is a single symbol (such as "2" or "5") used alone, or in combinations (such as "25"), to represent numbers (such as the number 25) according to some positional numeral systems.
Ogg is a free, open container format maintained by the Xiph.Org Foundation.
A payphone (alternative spelling: pay phone) is typically a coin-operated public telephone, often located in a telephone booth or a privacy hood, with pre-payment by inserting money (usually coins) or by billing a credit or debit card, or a telephone card.
The Precise Tone Plan is a signaling specification for the public switched telephone network (PSTN) in North America.
Pulse dialing is a signaling technology in telecommunications in which a direct current local loop circuit is interrupted according to a defined coding system for each signal transmitted, usually a digit.
A pure tone is a tone with a sinusoidal waveform; this is, a sine wave of any frequency, phase, and amplitude.
The push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to having a rotary dial as in earlier telephone instruments.
R2 - Specifications of Signalling System R2 is a 1950s- and 1970s-era channel-associated-signalling signalling protocol used outside of the former Bell System to convey information along a telephone trunk between two telephone switches in order to establish a single telephone call along that trunk.
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.
In a conventional, analog two-way radio system, a standard radio has ''noise squelch'' or ''carrier squelch'', which allows a radio to receive all transmissions.
In telecommunication, signaling has the following meanings.
Signaling System No.
A sine wave or sinusoid is a mathematical curve that describes a smooth periodic oscillation.
In telephony, a special information tone (SIT) is an in-band international standard signal consisting of three rising tones indicating a call has failed.
Subscriber trunk dialling (STD, also known as subscriber toll dialling) is a telephone system allowing subscribers to dial trunk calls without operator assistance.
In the early days of telephony, through roughly the 1960s, companies used manual telephone switchboards, and switchboard operators connected calls by inserting a pair of phone plugs into the appropriate jacks.
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.
A telephone call is a connection over a telephone network between the called party and the calling party.
A telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises.
A telephone keypad is the keypad installed on a push-button telephone or similar telecommunication device for dialing a telephone number.
The United States Armed Forces are the military forces of the United States of America.
A vertical service code (VSC) is a sequence of digits and the signals star (*) and number sign (#) dialed on a telephone keypad or rotary dial to enable or disable certain telephony service features.
The Video Home System (VHS) is a standard for consumer-level analog video recording on tape cassettes.
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