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Voice Logging
Voice logging is the practice of regularly recording telephone conversations. Business sectors which often do voice logging include public safety (e.g. 9-1-1 and emergency response systems), customer service call centers (conversations are recorded for quality assurance purposes), and finance (e.g. telephone-initiated stock trades are recorded for compliance purposes). Although voice logging is usually performed on conventional telephone lines, it is also frequently used for recording open microphones (e.g. on a stock trading floor) and for broadcast radio. Early voice loggers recorded POTS lines onto analog magnetic tape. As telephony became more digital, so did voice loggers, and starting in the 1990s, voice loggers digitized the audio using a codec and recorded to digital tape. With modern VoIP systems, many voice loggers now simply store calls to a file on a hard drive. History The original voice logging system was a large analog tape recorder developed by Magnasync in 1950. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9-1-1
, usually written 911, is an emergency telephone number for the United States, Canada, Mexico, Panama, Palau, Argentina, Philippines, Jordan, as well as the North American Numbering Plan (NANP), one of eight N11 codes. Like other emergency numbers around the world, this number is intended for use in emergency circumstances only. Using it for any other purpose (such as making false or prank calls) is a crime in most jurisdictions. In over 98% of locations in Argentina, Panama, Belize, Anguilla, Costa Rica, Ecuador, Jordan, Ethiopia, Liberia, Saudi Arabia, Philippines, Uruguay, United States, Palau, Mexico, Tonga and Canada, dialing "9-1-1" from any telephone will link the caller to an emergency dispatch office—called a Public Safety Answering Point (PSAP) by the telecommunications industry—which can send emergency responders to the caller's location in an emergency. In approximately 96 percent of the United States, the enhanced 9-1-1 system automatically pairs caller ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Old Telephone Service
Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from 1876 until 1988 in the United States when the Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) was introduced, followed by cellular telephone systems, and voice over IP (VoIP). POTS remains the basic form of residential and small business service connection to the telephone network in many parts of the world. The term reflects the technology that has been available since the introduction of the public telephone system in the late 19th century, in a form mostly unchanged despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN). Characteristics POTS is characterized by several aspects: *Bi-directional (full duplex) comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codec
A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or data stream, and hence is a type of codec. ''Endec'' is a portmanteau of encoder/decoder. A coder or encoder encodes a data stream or a signal for transmission or storage, possibly in encrypted form, and the decoder function reverses the encoding for playback or editing. Codecs are used in videoconferencing, streaming media, and video editing applications. History In the mid-20th century, a codec was a device that coded analog signals into digital form using pulse-code modulation (PCM). Later, the name was also applied to software for converting between digital signal formats, including companding functions. Examples An audio codec converts analog audio signals into digital signals for transmission or encodes them for storage. A receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VoIP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using special media delivery protocols t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Recorder
An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include the reel-to-reel tape deck and the cassette deck, which uses a cassette for storage. The use of magnetic tape for sound recording originated around 1930 in Germany as paper tape with oxide lacquered to it. Prior to the development of magnetic tape, magnetic wire recorders had successfully demonstrated the concept of magnetic recording, but they never offered audio quality comparable to the other recording and broadcast standards of the time. This German invention was the start of a long string of innovations that have led to present-day magnetic t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reel To Reel
Reel-to-reel audio tape recording, also called open-reel recording, is magnetic tape audio recording in which the recording tape is spooled between reels. To prepare for use, the ''supply reel'' (or ''feed reel'') containing the tape is placed on a spindle or hub. The end of the tape is manually pulled from the reel, threaded through mechanical guides and over a tape head assembly, and attached by friction to the hub of the second, initially empty ''takeup reel''. Reel-to-reel systems use tape that is wide, which normally moves at . All standard tape speeds are derived as a binary submultiple of 30 inches per second. Reel-to-reel preceded the development of the compact cassette with tape wide moving at . By writing the same audio signal across more tape, reel-to-reel systems give much greater fidelity at the cost of much larger tapes. In spite of the relative inconvenience and generally more expensive media, reel-to-reel systems developed in the early 1940s remained popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Cassette
The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens and his team at the Dutch company Philips in 1963, Compact Cassettes come in two forms, either already containing content as a prerecorded cassette (''Musicassette''), or as a fully recordable "blank" cassette. Both forms have two sides and are reversible by the user. Although other tape cassette formats have also existed - for example the Microcassette - the generic term ''cassette tape'' is normally always used to refer to the Compact Cassette because of its ubiquity. Its uses have ranged from portable audio to home recording to data storage for early microcomputers; the Compact Cassette technology was originally designed for dictation machines, but improvements in fidelity led to it supplanting the stereo 8-track cartridge and reel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcassette
The Microcassette (often written generically as microcassette) is an audio storage medium, introduced by Olympus in 1969. It has the same width of magnetic tape as the Compact Cassette but in a cassette roughly one quarter the size. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact cassette but in a smaller package. History Microcassettes have mostly been used for recording voice. In particular, they are commonly used in dictation machines and answering machines. Microcassettes have also been used in computer data storage and to record music. For the latter purpose, devices for recording in stereo were produced in 1982 and, for higher fidelity, microcassettes using Type IV ("metal", i.e. coated with pure metal particles rather than oxide) tape were sold. This was an attempt by Olympus to cash in on the burgeoning Walkman market; one model, the Olympus SR-11, had a built-in radio and offered a stereo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-carrier
The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls. The first version, the Transmission System 1 (T1), was introduced in 1962 in the Bell System, and could transmit up to 24 telephone calls simultaneously over a single transmission line of copper wire. Subsequent specifications carried multiples of the basic T1 (1.544 Mbit/s) data rates, such as T2 (6.312 Mbit/s) with 96 channels, T3 (44.736 Mbit/s) with 672 channels, and others. Although a ''T2'' was defined as part of AT&T's T-carrier system, which defined five levels, T1 through T5, only the T1 and T3 were commonly in use.1999 ad: On the left, in an aisle seat, a man who very much "filled" his airline seat while on the right side of the aisle is a height-challenged man whose shoe toes barely reach the floor Transmission System 1 The T-carrier is a hardware specification for carrying multiple time-division mul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-carrier
The E-carrier is a member of the series of carrier systems developed for digital transmission of many simultaneous telephone calls by time-division multiplexing. The European Conference of Postal and Telecommunications Administrations (CEPT) originally standardized the E-carrier system, which revised and improved the earlier American T-carrier technology, and this has now been adopted by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T). It was widely used in almost all countries outside the US, Canada, and Japan. E-carrier deployments have steadily been replaced by Ethernet as telecommunication networks transition towards all IP. E1 frame structure An E1 link operates over two separate sets of wires, usually unshielded twisted pair (balanced cable) or using coaxial (unbalanced cable). A nominal 3 volt peak signal is encoded with pulses using a method avoiding long periods without polarity changes. The line data rate is 2.048 Mbit/s ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual-tone Multi-frequency Signaling
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized as ITU-T Recommendation Q.23. It is also known in the UK as ''MF4''. The Touch-Tone system using a telephone keypad gradually replaced the use of rotary dial and has become the industry standard for landline and mobile service. Other multi-frequency systems are used for internal signaling within the telephone network. Multifrequency signaling Before the development of DTMF, telephone numbers were dialed by users with a loop-disconnect (LD) signaling, more commonly known as pulse dialing (dial pulse, DP) in the United States. It functions by int ... [...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 Union—Telecommunication 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 use by suicide-prevention hot lines and enabling businesses "like pizza restaurants and florists" to quickly have confidence in telephoned orders. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
