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High-speed Voice And Data Link
High-speed voice and data link (HVDL) is a high speed voice and data provisioning method that allows telcos and ISPs to provide up to three voice channels and data (up to 1Mbit/s) on a copper pair over extremely long local loops. Most DSL technologies (Etherloop in particular) work well up to about 18,000 feet (5.5 km) on a 24 AWG copper pair. Reach DSL supports lengths up to approximately 32,800 feet (10 km). HVDL has a theoretical maximum loop length of approximately 112,000 feet (approximately 34 km). Such a distance would require repeater(s) and would probably only support a connection of 128 kbit/s. The ideal speed for this service is 512 kbit/s or 384 kbit/s. This is programmed directly from the COT line card. The signal is sent from the telco's central office as an Ethernet style signal and is demuxed at the customer's premises by a POTS/Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Provisioning
In telecommunication, provisioning involves the process of preparing and equipping a network to allow it to provide new services to its users. In National Security/Emergency Preparedness telecommunications services, ''"provisioning"'' equates to ''"initiation"'' and includes altering the state of an existing priority service or capability. The concept of network provisioning or service mediation, mostly used in the telecommunication industry, refers to the provisioning of the customer's services to the network elements, which are various equipment connected in that network communication system. Generally in telephony provisioning this is accomplished with network management database table mappings. It requires the existence of networking equipment and depends on network planning and design. In a modern signal infrastructure employing information technology (IT) at all levels, there is no possible distinction between telecommunications services and "higher level" infrastructure. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Company
A telephone company, also known as a telco, telephone service provider, or telecommunications operator, is a kind of communications service provider (CSP), more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many telephone companies were at one time government agencies or privately owned but state-regulated monopolies. The government agencies are often referred to, primarily in Europe, as PTTs (postal, telegraph and telephone services). Telephone companies are common carriers, and in the United States are also called local exchange carriers. With the advent of mobile telephony, telephone companies now include wireless carriers, or mobile network operators. Most telephone companies now also function as internet service providers (ISPs), and the distinction between a telephone company and an ISP may disappear completely over time, as the current trend for supplier convergence in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Loop
In telephony, the local loop (also referred to as the 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. At the edge of the carrier access network in a traditional public telephone network, the local loop terminates in a circuit switch housed in an incumbent local exchange carrier or telephone exchange. Infrastructure Traditionally, the local loop was an electrical circuit in the form of a single pair of conductors from the telephone on the customer's premises to the local telephone exchange. Single-wire earth return lines had been used in some countries until the introduction of electric tramways from the 1900s made them unusable. Historically the first section was often an aerial open-wire line, with several conductors attached to porcelain insulators on cross-arms on "telegra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etherloop
Etherloop is a kind of DSL technology that combines the features of Ethernet and DSL. It allows the combination of voice and data transmission on standard phone lines. Under the right conditions it will allow speeds of up to 6 megabits per second over a distance of up to 6.4 km (21,000 feet). Etherloop uses half-duplex transmission, and as such, is less susceptible to interference caused by poor line quality, bridge taps, etc. Also, etherloop modems can train up through line filters (although it is not recommended to do this). Etherloop has been deployed by various internet service providers in areas where the loop length is very long or line quality is poor. Some Etherloop modems (those made by Elastic Networks) offer a "Central Office mode", in which two modems are connected back to back over a phone line and used as a LAN extension. An example of a situation where this would be done is to extend Ethernet to a building that is too far to reach with straight Ethernet. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate. There are several different types of repeaters; a telephone repeater is an amplifier in a telephone line, an optical repeater is an optoelectronic circuit that amplifies the light beam in an optical fiber cable; and a radio repeater is a radio receiver and transmitter that retransmits a radio signal. A broadcast relay station is a repeater used in broadcast radio and television. Overview When an information-bearing signal passes through a communication channel, it is progressively degraded due to loss of power. For example, when a telephone call passes through a wire telephone line, some of the powe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Card
A line card or digital line card is a modular electronic circuit designed to fit on a separate printed circuit board (PCB) and interface with a telecommunications access network. A line card typically interfaces the twisted pair cable of a plain old telephone service (POTS) local loop to the public switched telephone network (PSTN). Telephone line cards perform multiple tasks, such as analog-to-digital and digital-to-analog conversion of voice, off-hook detection, ring supervision, line integrity tests, and other BORSCHT functions. In some telephone exchange designs, the line cards generate ringing current and decode DTMF signals. The line card in a subscriber loop carrier is called a subscriber line interface card (SLIC). A line card can terminate a line supporting voice POTS service, ISDN service, DSL service, or proprietary ones. Some line cards are capable of terminating more than one type of service. Since an access network element is usually intended to interface many ... [...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] |
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET. The original 10BASE5 Ethernet uses coaxial cable as a shared medium, while the newer Ethernet variants use twisted pair and fiber optic links in conjunction with switches. Over the course of its history, Ethernet data transfer rates have been increased from the original to the latest , with rates up to under development. The Ethernet standards include several wiring and signaling variants of the OSI physical layer. Systems communicating over Ethernet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Customer-premises Equipment
In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation point ("demarc"). The demarc is a point established in a building or complex to separate customer equipment from the equipment located in either the distribution infrastructure or central office of the communications service provider. CPE generally refers to devices such as telephones, routers, network switches, residential gateways (RG), set-top boxes, fixed mobile convergence products, home networking adapters and Internet access gateways that enable consumers to access providers' communication services and distribute them in a residence or enterprise with a local area network (LAN). A CPE can be an active equipment, as the ones mentioned above, or passive equipment such as analogue telephone adapters (ATA) or xDSL-splitters. This inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Circuits
Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquiry studying them. There are many disagreements about its precise definition. John Peters argues that the difficulty of defining communication emerges from the fact that communication is both a universal phenomenon and a specific discipline of institutional academic study. One definitional strategy involves limiting what can be included in the category of communication (for example, requiring a "conscious intent" to persuade). By this logic, one possible definition of communication is the act of developing meaning among entities or groups through the use of sufficiently mutually understood signs, symbols, and semiotic conventions. An important distinction is between verbal communication, which happens through the use of a language, and non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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