131 relations: Acoustics, Amplitude modulation, Amplitude-shift keying, Analog signal, Analog transmission, Analog-to-digital converter, ASCII, Asymmetric digital subscriber line, Asynchronous serial communication, Automatic repeat request, AXE telephone exchange, Baseband, Bit, Bitstream, Bus (computing), Bus network, Byte, Cable modem, Channel access method, Character (computing), Check digit, Classical mechanics, Claude Shannon, Clock, Codec, Coding theory, Communication, Communication channel, Communication protocol, Computer, Computer engineering, Computer network, Computer science, Copper conductor, Cryptography, Data, Data compression, Data link layer, Data migration, Data storage, Data transmission, Data transmission circuit, Digital data, Digital radio, Digital signal, Digital signal processing, Digital television, Digital-to-analog converter, Digitization, Electrical engineering, ..., Electromagnetic field, Equalization (communications), Error detection and correction, Ethernet hub, Fiber to the x, Flow control (data), Forward error correction, Frame synchronization, Frequency modulation, Frequency-shift keying, Harry Nyquist, History of the telephone, IEEE 1394, Information, Information theory, Infrared, Integrated Services Digital Network, Inter-process communication, IPTV, Line code, Local area network, Media (communication), Medium access control, Mesh networking, Microwave, Microwave transmission, Mobile telephony, Modem, Modulation, Multicast, Multidrop bus, Multiplexing, Network security, Node-to-node data transfer, Optical fiber, Optics, OSI model, Parallel communication, Parallel port, Parity bit, Passband, Peripheral, Phase-shift keying, Physical layer, Point-to-point (telecommunications), Presentation layer, Pulse-code modulation, Radio frequency, Ralph Hartley, Repeater, Ring network, RS-232, Sampling (signal processing), Self-synchronizing code, Serial communication, Serial port, Signal, Signal element, Signal processing, Signaling (telecommunications), Simplex communication, Solid-state electronics, Star network, Telecommunication, Telegraphy, Telemetry, Telephone exchange, Teleprinter, Time-division multiplexing, Transmission, Transmission (telecommunications), Transmission Control Protocol, USB, Videotelephony, Voice over IP, Voltage, Wideband, Wireless, Wireless access point, Wireless network, 2G. Expand index (81 more) » « Shrink index
Acoustics is the branch of physics that deals with the study of all mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound.
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave.
Amplitude-shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave.
An analog signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal.
Analog transmission is a transmission method of conveying information using a continuous signal which varies in amplitude, phase, or some other property in proportion to that information.
In electronics, an analog-to-digital converter (ADC, A/D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal.
ASCII, abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication.
Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide.
Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal.
Automatic repeat request (ARQ), also known as automatic repeat query, is an error-control method for data transmission that uses acknowledgements (messages sent by the receiver indicating that it has correctly received a data frame or packet) and timeouts (specified periods of time allowed to elapse before an acknowledgment is to be received) to achieve reliable data transmission over an unreliable service.
The AXE telephone exchange is a product line of circuit switched digital telephone exchanges manufactured by Ericsson, a Swedish telecom company.
Baseband is a signal that has a very narrow and near-zero frequency range, i.e. a spectral magnitude that is nonzero only for frequencies in the vicinity of the origin (termed f.
The bit (a portmanteau of binary digit) is a basic unit of information used in computing and digital communications.
A bitstream (or bit stream), also known as binary sequence, is a sequence of bits.
In computer architecture, a bus (a contraction of the Latin omnibus) is a communication system that transfers data between components inside a computer, or between computers.
A bus network is a network topology in which nodes are directly connected to a common linear (or branched) half-duplex link called a bus.
The byte is a unit of digital information that most commonly consists of eight bits, representing a binary number.
A cable modem is a type of network bridge that provides bi-directional data communication via radio frequency channels on a hybrid fibre-coaxial (HFC) and radio frequency over glass (RFoG) infrastructure.
In telecommunications and computer networks, a channel access method or multiple access method allows several terminals connected to the same multi-point transmission medium to transmit over it and to share its capacity.
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language.
A check digit is a form of redundancy check used for error detection on identification numbers, such as bank account numbers, which are used in an application where they will at least sometimes be input manually.
Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars and galaxies.
Claude Elwood Shannon (April 30, 1916 – February 24, 2001) was an American mathematician, electrical engineer, and cryptographer known as "the father of information theory".
A clock is an instrument to measure, keep, and indicate time.
A codec is a device or computer program for encoding or decoding a digital data stream or signal.
Coding theory is the study of the properties of codes and their respective fitness for specific applications.
Communication (from Latin commūnicāre, meaning "to share") is the act of conveying intended meanings from one entity or group to another through the use of mutually understood signs and semiotic rules.
A communication channel or simply channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking.
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.
A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming.
Computer engineering is a discipline that integrates several fields of computer science and electronics engineering required to develop computer hardware and software.
A computer network, or data network, is a digital telecommunications network which allows nodes to share resources.
Computer science deals with the theoretical foundations of information and computation, together with practical techniques for the implementation and application of these foundations.
Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s.
Cryptography or cryptology (from κρυπτός|translit.
Data is a set of values of qualitative or quantitative variables.
In signal processing, data compression, source coding, or bit-rate reduction involves encoding information using fewer bits than the original representation.
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking.
Data migration is the process of transferring data between computer storage types or file formats.
Data storage is the recording (storing) of information (data) in a storage medium.
Data transmission (also data communication or digital communications) is the transfer of data (a digital bitstream or a digitized analog signal) over a point-to-point or point-to-multipoint communication channel.
In telecommunication, a data transmission circuit is the transmission media and the intervening equipment used for the data transfer between data terminal equipments (DTEs).
Digital data, in information theory and information systems, is the discrete, discontinuous representation of information or works.
Digital radio is the use of digital technology to transmit and/or receive across the radio spectrum.
A digital signal is a signal that is being used to represent data as a sequence of discrete values; at any given time it can only take on one of a finite number of values.
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.
Digital television (DTV) is the transmission of television signals, including the sound channel, using digital encoding, in contrast to the earlier television technology, analog television, in which the video and audio are carried by analog signals.
In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal.
Digitization, at WhatIs.com in Collins English Dictionary less commonly digitalization, is the process of converting information into a digital (i.e. computer-readable) format, in which the information is organized into bits.
Electrical engineering is a professional engineering discipline that generally deals with the study and application of electricity, electronics, and electromagnetism.
An electromagnetic field (also EMF or EM field) is a physical field produced by electrically charged objects.
In telecommunication, equalization is the reversal of distortion incurred by a signal transmitted through a channel.
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction or error control are techniques that enable reliable delivery of digital data over unreliable communication channels.
An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ethernet devices together and making them act as a single network segment.
Fiber to the x (FTTX) or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications.
In data communications, flow control is the process of managing the rate of data transmission between two nodes to prevent a fast sender from overwhelming a slow receiver.
In telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels.
In telecommunication, frame synchronization or framing is the process by which, while receiving a stream of framed data, incoming frame alignment signals (i.e., a distinctive bit sequences or syncwords) are identified (that is, distinguished from data bits), permitting the data bits within the frame to be extracted for decoding or retransmission.
In telecommunications and signal processing, frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave.
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal.
Harry Nyquist (born Harry Theodor Nyqvist,; February 7, 1889 – April 4, 1976) was a Swedish-born American electronic engineer who made important contributions to communication theory.
This history of the telephone chronicles the development of the electrical telephone, and includes a brief review of its predecessors.
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer.
Information is any entity or form that provides the answer to a question of some kind or resolves uncertainty.
Information theory studies the quantification, storage, and communication of information.
Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network.
In computer science, inter-process communication or interprocess communication (IPC) refers specifically to the mechanisms an operating system provides to allow the processes to manage shared data.
Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks.
Some signals are more prone to error than others when conveyed over a communication channel as the physics of the communication or storage medium constrains the repertoire of signals that can be used reliably.
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building.
Media are the collective communication outlets or tools used to store and deliver information or data.
In IEEE 802 LAN/MAN standards, the medium access control (MAC) sublayer (also known as the media access control sublayer) and the logical link control (LLC) sublayer together make up the data link layer.
A mesh network is a local network topology in which the infrastructure nodes (i.e. bridges, switches and other infrastructure devices) connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data from/to clients.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between and.
Microwave transmission is the transmission of information or energy by microwave radio waves.
Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location.
A modem (modulator–demodulator) is a network hardware device that modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information.
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.
In computer networking, multicast is group communication where data transmission is addressed to a group of destination computers simultaneously.
A multidrop bus (MDB) is a computer bus in which all components are connected to the electrical circuit.
In telecommunications and computer networks, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium.
Network security consists of the policies and practices adopted to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources.
In telecommunications, node-to-node data transfer is the movement of data from one node of a network to the next.
An optical fiber or optical fibre is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair.
Optics is the branch of physics which involves the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.
The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.
In data transmission, parallel communication is a method of conveying multiple binary digits (bits) simultaneously.
A parallel port is a type of interface found on computers (personal and otherwise) for connecting peripherals.
A parity bit, or check bit, is a bit added to a string of binary code to ensure that the total number of 1-bits in the string is even or odd.
A passband is the range of frequencies or wavelengths that can pass through a filter.
A peripheral device is "an ancillary device used to put information into and get information out of the computer." Three categories of peripheral devices exist based on their relationship with the computer.
Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave).
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer.
In telecommunications, a point-to-point connection refers to a communications connection between two Communication endpoints or nodes.
In the seven-layer OSI model of computer networking, the presentation layer is layer 6 and serves as the data translator for the network.
Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals.
Radio frequency (RF) refers to oscillatory change in voltage or current in a circuit, waveguide or transmission line in the range extending from around twenty thousand times per second to around three hundred billion times per second, roughly between the upper limit of audio and the lower limit of infrared.
Ralph Vinton Lyon Hartley (November 30, 1888 – May 1, 1970) was an electronics researcher.
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it.
A ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring.
In telecommunications, RS-232, Recommended Standard 232 is a standard introduced in 1960 for serial communication transmission of data.
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal.
In coding theory, especially in telecommunications, a self-synchronizing code is a uniquely decodable code in which the symbol stream formed by a portion of one code word, or by the overlapped portion of any two adjacent code words, is not a valid code word.
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus.
In computing, a serial port is a serial communication interface through which information transfers in or out one bit at a time (in contrast to a parallel port).
A signal as referred to in communication systems, signal processing, and electrical engineering is a function that "conveys information about the behavior or attributes of some phenomenon".
In signal theory, a signal element is a part of a signal that is distinguished by its.
Signal processing concerns the analysis, synthesis, and modification of signals, which are broadly defined as functions conveying "information about the behavior or attributes of some phenomenon", such as sound, images, and biological measurements.
In telecommunication, signaling has the following meanings.
Simplex communication is a communication channel that sends information in one direction only.
Solid-state electronics means semiconductor electronics; electronic equipment using semiconductor devices such as semiconductor diodes, transistors, and integrated circuits (ICs).
A Star network is one of the most common computer network topologies.
Telecommunication is the transmission of signs, signals, messages, words, writings, images and sounds or information of any nature by wire, radio, optical or other electromagnetic systems.
Telegraphy (from Greek: τῆλε têle, "at a distance" and γράφειν gráphein, "to write") is the long-distance transmission of textual or symbolic (as opposed to verbal or audio) messages without the physical exchange of an object bearing the message.
Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to receiving equipment for monitoring.
A telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises.
A teleprinter (teletypewriter, Teletype or TTY) is an electromechanical typewriter that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations.
Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern.
Transmission may refer to.
In telecommunications, transmission (abbreviations: TX, Xmit) is the process of sending and propagating an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless.
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite.
USB (abbreviation of Universal Serial Bus), is an industry standard that was developed to define cables, connectors and protocols for connection, communication, and power supply between personal computers and their peripheral devices.
Videotelephony comprises the technologies for the reception and transmission of audio-video signals by users at different locations, for communication between people in real-time.
Voice over Internet Protocol (also voice over IP, VoIP or IP telephony) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.
Voltage, electric potential difference, electric pressure or electric tension (formally denoted or, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's circuit laws) is the difference in electric potential between two points.
In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel.
Wireless communication, or sometimes simply wireless, is the transfer of information or power between two or more points that are not connected by an electrical conductor.
20018 In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows a Wi-Fi device to connect to a wired network.
A wireless network is a computer network that uses wireless data connections between network nodes.
2G (or 2-G) is short for second-generation cellular technology.
Asynchronous data transfer, Asynchronous data transmission, Asynchronous transmission, Comms, Data Communications, Data Transfer, Data communication, Data communications, Data signal, Data transfer, Digital Communication, Digital Telecommunications, Digital communication, Digital communications, Digital signal (communications), Digital telecommunication, Digital telecommunications, Digital transmission, Information transmission, Network Transmission, Synchronous data transfer, Synchronous data transmission, Synchronous transmission, Transmitted Data.