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Simultaneous Voice And Data
In telecommunications, a system that supports simultaneous voice and data (SVD) is one that can transceive both voice and primary data concurrently over one PSTN modem. Background Before telecommunication networks began to support data related services, the bearer channel was dedicated solely to voice information. When support for data related services was originally released, the bearer channel was switched between being dedicated to voice information or dedicated to primary data information, depending on the subscriber's needs at any given time. Eventually, support for simultaneous voice and data transmission was added to modems and mobile devices, to enable subscribers to use voice and data services at the same time. Types * Digital Simultaneous Voice and Data, or DSVD, defined by the ITU-T V.70 standard. * Analog Simultaneous Voice and Data, or ASVD, defined by the ITU-T V.61 standard. * Data over signalling, or DoS, wherein data is multiplexed onto the signalling chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. ''Telecommunication'' is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transceiver
In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. These two related functions are often combined in a single device to reduce manufacturing costs. The term is also used for other devices which can both transmit and receive through a communications channel, such as ''optical transceivers'' which transmit and receive light in optical fiber systems, and ''bus transceivers'' which transmit and receive digital data in computer data buses. Radio transceivers are widely used in wireless devices. One large use is in two-way radios, which are audio transceivers used for bidirectional person-to-person voice communication. Examples are cell phones, which transmit and receive the two sides of a phone conversation using radio waves to a cell tower, cordless phones in which both the phone handset ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted. A datum is an individual value in a collection of data. Data is usually organized into structures such as tables that provide additional context and meaning, and which may themselves be used as data in larger structures. Data may be used as variables in a computational process. Data may represent abstract ideas or concrete measurements. Data is commonly used in scientific research, economics, and in virtually every other form of human organizational activity. Examples of data sets include price indices (such as consumer price index), unemployment rates, literacy rates, and census data. In this context, data represents the raw facts and figures which can be used in such a manner in order to capture the useful information out of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha .... The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators. These consist of telephone lines, fiber optic cables, microwave transmission links, Routing in cellular networks, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers which allow most telephones to communicate with each other. Originally a network of fixed-line Analog signal processing, analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information. The goal is to produce a signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from light-emitting diodes to radio. Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines. These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset. By the 1970s, higher speeds of 1,200 and 2,400 bit/s for asynchronous dial connections, 4,800 bit/s for synch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearer Channel
A bearer channel is a DS-0 that carries call content i.e. one that does not carry signaling In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' .... In the common-channel signaling scheme for telecommunications, signaling is sent out-of-band, while all other traffic rides bearer channels. When a call is set up, the Bearer Capability is negotiated, and this is used to determine what type of traffic is sent across the bearer channel. Bearer channels are the most prevalent types of DS-0s in the Digital Transmission Hierarchies. The most well known example of a bearer channel is the ISDN B channel. See also * Bearer service {{DEFAULTSORT:Bearer Channel Telephony signals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MODEM
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information. The goal is to produce a signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from light-emitting diodes to radio. Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines. These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset. By the 1970s, higher speeds of 1,200 and 2,400 bit/s for asynchronous dial connections, 4,800 bit/s for synch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-T V
The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Communication Technology such as X.509 for cybersecurity, Y.3172 and Y.3173 for machine learning, and H.264/MPEG-4 AVC for video compression, between its Member States, Private Sector Members, and Academia Members. The first meeting of the World Telecommunication Standardization Assembly (WTSA), the sector's governing conference, took place on 1 March of that year. ITU-T has a permanent secretariat called the Telecommunication Standardization Bureau (TSB), which is based at the ITU headquarters in Geneva, Switzerland. The current director of the TSB is Chaesub Lee (of South Korea), whose first 4-year term commenced on 1 January 2015, and whose second 4-year term commenced on 1 January 2019. Chaesub Lee succeeded Malcolm Johnson of the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Over Signalling
Data over signalling (sometimes data over signaling) or DoS, is a technique in telecommunications in which primary data is sent over a signalling channel instead of the subscriber's bearer channel A bearer channel is a DS-0 that carries call content i.e. one that does not carry signaling In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used a .... Background Data over signalling was designed as a solution to the problem of transceiving simultaneous voice and data. Data over signalling can be utilized when the signalling channel is either channel associated or common. However, it is easier to implement when the signalling channel is channel associated, as the system does not have to demultiplex the data and signalling between multiple subscribers. DoS was designed so that mobile telephony subscribers could maintain a voice session on their bearer channel while still accessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combined Voice And Data
{{Disambiguation ...
Combined may refer to: * Alpine combined (skiing), the combination of slalom and downhill skiing as a single event ** Super combined (skiing) * Nordic combined (skiing), the combination of cross country skiing and ski jumping as a single event * The Combined (Group), a criminal organization See also * * Combo (other) * Combine (other) * Combination (other) A combination is a mathematical collection of things in a context where their specific order is irrelevant. Combination, combinations, or combo may also refer to: * Combination (chess), a relatively long sequence of chess moves, involving tempo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplexing
In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a physical transmission medium. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now widely applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910. The multiplexed signal is transmitted over a communication channel such as a cable. The multiplexing divides the capacity of the communication channel into several logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, extracts the original channels on the receiver end. A device that performs the multiplexing is called a multiplexer (MUX), and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Activity Detection
Voice activity detection (VAD), also known as speech activity detection or speech detection, is the detection of the presence or absence of human speech, used in speech processing. The main uses of VAD are in speech coding and speech recognition. It can facilitate speech processing, and can also be used to deactivate some processes during non-speech section of an audio session: it can avoid unnecessary coding/transmission of silence packets in Voice over Internet Protocol (VoIP) applications, saving on computation and on network bandwidth. VAD is an important enabling technology for a variety of speech-based applications. Therefore, various VAD algorithms have been developed that provide varying features and compromises between latency, sensitivity, accuracy and computational cost. Some VAD algorithms also provide further analysis, for example whether the speech is voiced, unvoiced or sustained. Voice activity detection is usually independent of language. It was first investigat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
