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Ringing (telephony)
Ringing is a telecommunication signal that causes a telephone to emit a noise (or other signal), indicating an incoming call. Historically, this entailed sending a high-voltage alternating current over the line to a customer’s telephone, which contained an electromagnetic bell. It is thus referred to as ''power ringing'' when distinguishing it from another signal, audible or tone ringing, which is sent to the caller’s handset to indicate that the recipient’s phone is in fact ringing. Specifications In landline telephones, bells or ringtones are rung by impressing a 60 to 105-volt RMS 15 to 25 Hertz sine wave (depending on manufacturer and telecoms administration) across the conductor pair of the subscriber line, typically represented by tip and ring, in series with the (typically) −48 VDC loop supply. This signal is produced by a ringing generator at the central office. When the switching system directs a call to a particular subscriber line, a relay on the line c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phone Phreak
Phreaking is a slang term coined to describe the activity of a culture of people who study, experiment with, or explore telecommunication systems, such as equipment and systems connected to public telephone networks. The term ''phreak'' is a sensational spelling of the word '' freak'' with the ''ph-'' from '' phone'', and may also refer to the use of various audio frequencies to manipulate a phone system. ''Phreak'', ''phreaker'', or ''phone phreak'' are names used for and by individuals who participate in phreaking. The term first referred to groups who had reverse engineered the system of tones used to route long-distance calls. By re-creating the signaling tones, phreaks could switch calls from the phone handset while avoiding long-distance calling charges which were common then. These fees could be significant, depending on the time, duration and destination of the call. To ease the creation of the routing tones, electronic tone generators known as blue boxes became a stap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringtone
A ringtone is the sound made by a telephone to indicate an incoming telephone call. Originally referring to the sound of electromechanical striking of bells or gongs, the term refers to any sound by any device alerting of an incoming call. On plain old telephone services (POTS), starting in the late 19th century, the signal is created by superimposing ringing voltage on the direct current line voltage. Electronic telephones could produce a warbling, chirping, or other sounds. Variations of the cadence or tone of the ring signal, called ''distinctive ringing'', can be used to indicate characteristics of incoming calls. Modern telephones, especially smartphones, are manufactured with a preloaded selection of ringtones. Customers can buy or generate custom ringtones for installation on the device as a default ringtone or a distinctive ringtone used to indicate characteristics of incoming calls. Digital ringtones were a large market in the 2000s, at its peak generating up to $4 bill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Signaling
Line signaling is a class of telecommunications signaling protocols. Line signaling is responsible for off-hook, ringing signal, answer, ground start, on-hook unidirectional supervision messaging in each direction from calling party to called party and vice versa. After an off-hook, line signaling initiates register signaling to accomplish the exchange of telephone numbers of called party and in more modern line-signaling protocols, the calling party as well. While register signaling occurs, line signaling remains quiescent unless the calling party goes on-hook or an abnormal cessation of the call occurs, such as due to equipment malfunction or shutdown or due to network outage upstream in that call-attempt's series of spanned trunks. Line signaling can be conveyed in a single DS0 channel of a trunk. In modern PCM telecommunications, line signaling is represented by the ABCD bits in DS0 #16 of an E1 or a selected DS0 within a T1. Line signaling can also be conveyed with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as data packets, facilitating various methods of voice communication, including traditional applications like Skype, Microsoft Teams, Google Voice, and VoIP phones. Regular telephones can also be used for VoIP by connecting them to the Internet via analog telephone adapters (ATAs), which convert traditional telephone signals into digital data packets that can be transmitted over IP networks. The broader terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the delivery of voice and other communication services, such as fax, SMS, and voice messaging, over the Internet, in contrast to the traditional public switched telephone network (PSTN), commonly known as plain old telephone service (POTS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Telephone Adapter
An analog telephone adapter (ATA) or FXS gateway is a device for connecting traditional analog telephones, fax machines, and similar customer-premises devices to a digital telephone system or a voice over IP telephone network. An ATA is often built into a small enclosure with an internal or external power adapter, an Ethernet port, and one or more foreign exchange station (FXS) telephone ports. Such devices may also have a foreign exchange office (FXO) interface for providing alternative access to traditional landline telephone service. The ATA provides dial tone, ringing generator, DC power, caller ID data and other standard telephone line signaling (known collectively as BORSCHT) to the telephone connected to a modular jack. The digital interface of the ATA typically consists of an Ethernet port to connect to an Internet Protocol (IP) network, but may also be a USB port for connecting the device to a personal computer. Using such an ATA, it is possible to connect a conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stage Prop
Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Stages Repertory Theatre, a theatre company in Houston, Texas Music Performers * Stage, an American band featuring Ryan Star Albums * ''Stage'' (David Bowie album), 1978 * ''Stage'' (Great White album), 1995 * ''Stage'' (Keller Williams album), 2004 * ''Stage'', by Mónica Naranjo, 2009 * ''The Stage'' (album), by Avenged Sevenfold, or the title song (see below), 2016 * ''Stages'' (Cassadee Pope album), 2019 * ''Stages'' (Elaine Paige album), 1983 * ''Stages'' (Eric Clapton album), 1993 * ''Stages'' (Jimi Hendrix album), 1991 * ''Stages'' (Josh Groban album), 2015 * ''Stages'' (Melanie C album), 2012 * ''Stages'' (Triumph album), 1985 * ''Stages'' (Vedera album), 2009 * '' Stages: The Lost Album'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercom
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. Intercoms are used on a wide variety of properties; from houses that only require one connection between a resident and the property's entrance to multi-unit apartments that require intercom hardware to be installed in every individual apartment. Some are equipped with video and its wiring (electrical installation) can be connected to the outside with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Private Branch Exchange
A business telephone system is a telephone system typically used in business environments, encompassing the range of technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone system differs from an installation of several telephones with multiple central office (CO) lines in that the CO lines used are directly controllable in key telephone systems from multiple telephone stations, and that such a system often provides additional features for call handling. Business telephone systems are often broadly classified into key telephone systems and private branch exchanges, but many combinations (hybrid telephone systems) exist. A key telephone system was originally distinguished from a private branch exchange in that it did not require an operator or attendant at a switchboard to establish connections between the central office trunks and stations, or between stations. Technologically, private branch exchanges share lineage with central ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits, enabling telephone calls between subscribers. The term "central office" can also refer to a central location for fiber optic equipment for a fiber internet provider. In historical perspective, telecommunication terminology has evolved with time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. A central office is defined as the telephone switch controlling connections for one or more central office prefixes. However, it also often denotes the building used to house the inside plant equipment for multiple telephone exchange areas. In North America, the term ''wire center'' may be used to denote a central office location, indicating a facility that provides a telephone with a dial tone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vermilion Box
A vermilion box is a (hypothetical) portable telephone line emulator used for phreaking, whose function is to Caller ID spoofing, spoof all of the aspects of an incoming Telephone call, phone call—Direct current, DC Voltage, line voltage, an Alternating current, AC Ringing (telephony), ringing signal and caller ID—while the line is disconnected from the public switched telephone network (PSTN), as well as allow the user to communicate with the recipient if the call is answered. Its use requires a physical connection to the circuit somewhere between the target premises and the Telephone exchange, exchange (in either the local loop or the access network), but when properly applied, results in a stealth-intensive incoming call that appears completely genuine but which cannot be electronically traced. Typically, the user physically disconnects the target line from the network or causes an outage in the system, connects the vermilion box, and then initiates the illicit call. Compone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caller ID
Caller identification (Caller ID) is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment when the call is being set up. The caller ID service may include the transmission of a name associated with the calling telephone number, in a service called Calling Name Presentation (CNAM). The service was first defined in 1993 in International Telecommunication UnionTelecommunication Standardization Sector (ITU-T) Recommendation Q.731.3. The information received from the service is displayed on a telephone display screen, on a separately attached device, or on other displays, such as cable television sets when telephone and television service is provided by the same vendor. Value to society includes allowing suicide-prevention hotlines to quickly identify a caller, and enabling businesses (for an example, restaurants and florists) to quickly have co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
