88 relations: Alarm indication signal, American National Standards Institute, American wire gauge, Analog signal, AT&T, AT&T Communications, Bandwidth (signal processing), Baud, Bell Labs, Bell System, Bipolar encoding, Bipolar violation, Bit, Bit rate, Bitstream, BNC connector, Bridge tap, Carrier system, Carrier wave, Channel bank, Chicago, Coaxial cable, Codec, Communication protocol, Communications in Japan, Companding, Comparison of T-carrier and E-carrier systems, Competitive local exchange carrier, Copper conductor, CSU/DSU, Data terminal equipment, Data transmission, Data-rate units, Digital Signal 1, Digital Signal 3, Direct current, E-carrier, Electric Lightwave, Empiricism, European Conference of Postal and Telecommunications Administrations, Extended superframe, Frame synchronization, Frequency-division multiplexing, Guard band, Hertz, High-bit-rate digital subscriber line, Integrated Services Digital Network, L-carrier, Level 3 Communications, List of interface bit rates, ..., Loading coil, Local loop, Megabit, Microwave transmission, Modified AMI code, Multiplexing, Nyquist rate, Operations, administration and management, Optical Carrier transmission rates, Outside plant, Plesiochronous digital hierarchy, Pulse-code modulation, Qwest, Repeater, Robbed-bit signaling, Signalling System No. 7, Specification (technical standard), STM-1, Superframe, Synchronous optical networking, Telecommunications in South Korea, Telephone call, Telephone exchange, Ternary signal, Time-division multiple access, Time-division multiplexing, TPx Communications, Trunking, TW Telecom, Twisted pair, Utility tunnel, Verizon Communications, Videotelephony, Voice frequency, Windstream Holdings, XO Communications, 12-channel carrier system, 4B3T. Expand index (38 more) » « Shrink index
Alarm indication signal (AIS) (also called “all ones” because of the data and framing pattern) is a signal transmitted by an intermediate element of a multi-node transport circuit that is part of a concatenated telecommunications system to alert the receiving end of the circuit that a segment of the end-to-end link has failed at a logical or physical level, even if the system it is directly connected to is still working.
The American National Standards Institute (ANSI) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.
American wire gauge (AWG), also known as the Brown & Sharpe wire gauge, is a logarithmic stepped standardized wire gauge system used since 1857 predominantly in North America for the diameters of round, solid, nonferrous, electrically conducting wire.
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.
AT&T Inc. is an American multinational conglomerate holding company headquartered at Whitacre Tower in Downtown Dallas, Texas.
AT&T Communications, Inc., was a division of the AT&T Corporation that, through 23 subsidiaries, provided interexchange carrier and long distance telephone services.
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.
In telecommunication and electronics, baud (symbol: Bd) is a common measure of the speed of communication over a data channel.
Nokia Bell Labs (formerly named AT&T Bell Laboratories, Bell Telephone Laboratories and Bell Labs) is an American research and scientific development company, owned by Finnish company Nokia.
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.
In telecommunication, bipolar encoding is a type of return-to-zero (RZ) line code, where two nonzero values are used, so that the three values are +, −, and zero.
A bipolar violation, bipolarity violation, or BPV, is a violation of the bipolar encoding rules where two pulses of the same polarity occur without an intervening pulse of the opposite polarity.
The bit (a portmanteau of binary digit) is a basic unit of information used in computing and digital communications.
In telecommunications and computing, bit rate (bitrate or as a variable R) is the number of bits that are conveyed or processed per unit of time.
A bitstream (or bit stream), also known as binary sequence, is a sequence of bits.
The BNC (Bayonet Neill–Concelman) connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable.
Bridged tap or bridge tap is a long-used method of cabling for telephone lines.
A carrier system is a telecommunications system that transmits information, such as the voice signals of a telephone call and the video signals of television, by modulation of one or multiple carrier signals above the principal voice frequency or data rate.
In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an input signal for the purpose of conveying information.
In telecommunications, a channel bank is a device that performs multiplexing or demultiplexing ("demux") of a group of communications channels, such as analog or digital telephone lines, into one channel of higher bandwidth or higher digital bit rate, such as a DS-1 (T1) circuit, so that all the channels can be sent simultaneously over a single cable called a trunkline.
Chicago, officially the City of Chicago, is the third most populous city in the United States, after New York City and Los Angeles.
Cross-sectional view of a coaxial cable Coaxial cable, or coax (pronounced), is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield.
A codec is a device or computer program for encoding or decoding a digital data stream or signal.
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.
The nation of Japan currently possesses one of the most advanced communication networks in the world.
In telecommunication and signal processing companding (occasionally called compansion) is a method of mitigating the detrimental effects of a channel with limited dynamic range.
The DS designations are used in connection with the North American hierarchy only.
A competitive local exchange carrier (CLEC), in the United States and Canada, is a telecommunications provider company (sometimes called a "carrier") competing with other, already established carriers (generally the incumbent local exchange carrier (ILEC)).
Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s.
A CSU/DSU (Channel Service Unit/Data Service Unit) is a digital-interface device used to connect data terminal equipment (DTE), such as a router, to a digital circuit, such as a Digital Signal 1 (DS1) T1 line.
Data terminal equipment (DTE) is an end instrument that converts user information into signals or reconverts received signals.
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 telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system.
Digital Signal 1 (DS1, sometimes DS-1) is a T-carrier signaling scheme devised by Bell Labs.
A Digital Signal 3 (DS3) is a digital signal level 3 T-carrier.
Direct current (DC) is the unidirectional flow of electric charge.
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.
Electric Lightwave, formerly known as Integra was a privately owned provider of fiber-based, carrier-grade networking, communications and technology solutions, headquartered in Vancouver, Washington, United States.
In philosophy, empiricism is a theory that states that knowledge comes only or primarily from sensory experience.
The European Conference of Postal and Telecommunications Administrations (CEPT) was established on June 26, 1959, as a coordinating body for European state telecommunications and postal organizations.
In telecommunications, extended superframe (ESF) is a T1 framing standard.
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, frequency-division multiplexing (FDM) is a technique by which the total bandwidth available in a communication medium is divided into a series of non-overlapping frequency bands, each of which is used to carry a separate signal.
In radio, a guard band is an unused part of the radio spectrum between radio bands, for the purpose of preventing interference.
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.
High-bit-rate digital subscriber line (HDSL) is a telecommunications protocol standardized in 1994.
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.
The Transcontinental Cable System or L-carrier system was developed by AT&T to create a high capacity transmission facility using coaxial cable, a fairly new medium for HF to RF signal transmission invented in 1927 by Lloyd Espenschied of Bell Telephone Laboratories for long distance communications.
Level 3 Communications was an American multinational telecommunications and Internet service provider company headquartered in Broomfield, Colorado.
This is a list of interface bit rates, is a measure of information transfer rates, or digital bandwidth capacity, at which digital interfaces in a computer or network can communicate over various kinds of buses and channels.
A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance.
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.
The megabit is a multiple of the unit bit for digital information.
Microwave transmission is the transmission of information or energy by microwave radio waves.
Modified AMI codes are a digital telecommunications technique to maintain system synchronization.
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.
In signal processing, the Nyquist rate, named after Harry Nyquist, is twice the bandwidth of a bandlimited function or a bandlimited channel.
Operations, administration and management or operations, administration and maintenance (OA&M or OAM) are the processes, activities, tools, and standards involved with operating, administering, managing and maintaining any system.
Optical Carrier transmission rates are a standardized set of specifications of transmission bandwidth for digital signals that can be carried on Synchronous Optical Networking (SONET) fiber optic networks.
In telecommunication, the term outside plant has the following meanings.
The plesiochronous digital hierarchy (PDH) is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fibre optic and microwave radio systems.
Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals.
Qwest Communications International, Inc. was a large United States telecommunications carrier.
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it.
In communication systems, robbed-bit signaling is a scheme to provide maintenance and line signaling services on many T1 digital carrier circuits using channel-associated signaling (CAS).
Signaling System No.
A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service.
The STM-1 (Synchronous Transport Module level-1) is the SDH ITU-T fiber optic network transmission standard.
In telecommunications, superframe (SF) is a T1 framing standard.
Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs).
Communications services improved dramatically in the 1980s with the assistance of foreign partners and as a result of the development of the electronics industry.
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.
In telecommunication, a ternary signal is a signal that can assume, at any given instant, one of three states or significant conditions, such as power level, phase position, pulse duration, or frequency.
Time-division multiple access (TDMA) is a channel access method for shared-medium networks.
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.
In telecommunications, trunking is a method for a system to provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually.
TW Telecom (styled tw telecom), was a business telecommunications company headquartered in Littleton, Colorado, United States.
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility.
A utility tunnel, utility corridor, or utilidor is a passage built underground or above ground to carry utility lines such as electricity, steam, water supply pipes, and sewer pipes.
Verizon Communications Inc., or simply Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones Industrial Average.
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.
A voice frequency (VF) or voice band is one of the frequencies, within part of the audio range, that is being used for the transmission of speech.
Windstream Holdings, Inc., also doing business as Windstream Communications or Windstream, is a provider of voice and data network communications (broadband, VoIP, MPLS), and managed services (virtual servers, managed firewall, data storage, cloud-based voice, etc.), to businesses in the United States.
XO Communications (previously Nextlink Communications, Concentric Network Corporation and Allegiance Telecom, Inc. is a telecommunications company owned by XO Holdings, Inc (OTCBB: XOHO). XO provides managed and converged Internet Protocol (IP) network services for small and medium-sized enterprises. XO delivers services through a mix of fiber-based Ethernet and Ethernet over Copper (EoC). In addition, the company has external network-to-network interface (E-NNI) agreements with traditional carriers and cable companies.
In the U.S. telephone network, the 12-channel carrier system was an early frequency-division multiplexing system standard, used to carry multiple telephone calls on a single twisted pair of wires, mostly for short to medium distances.
4B3T, which stands for 4 (four) Binary 3 (three) Ternary, is a line encoding scheme used for ISDN PRI interface.