|
D-side (UK Telephone Cabling)
In a UK telephone line, the term D-side or distribution side refers at any point on a local loop connection between a customer's premises and a telephone exchange to the wires (or pairs of copper wires) leaving into the direction of the customer. Conversely, E-side is the exchange side of a telephone line, that is the wires leaving any connection point into the direction of the telephone exchange. These terms are used, for example, by technicians of Openreach, Virgin Media Virgin Media is a British telecommunications company which provides telephone, television and internet services in the United Kingdom. Its headquarters are at Green Park in Reading, England. It is owned by Virgin Media O2, a 50:50 joint ventu ... and other UK phone companies when referring to wiring connections going from a Primary Connection Point (PCP) telecoms cabinet to a point closer to a residence or business known as the "Distribution Point" (DP). On its way, it may pass through a Secondary Connec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Line
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user. Telephone lines are used to deliver landline telephone service and Digital subscriber line (DSL) phone cable service to the premises. Telephone overhead lines are connected to the public switched telephone network. The voltage at a subscriber's network interface is typically 48 V between the ring and tip wires, with tip near ground and ring at -48 V. In the United States In 1878, the Bell Telephone Company began to use two-wire circuits, called the local loop, from each user's telephone to end offices which performed any necessary electrical s ... [...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] |
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] |
Twisted Pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. For additional noise immunity, twisted-pair cabling may be shielded. Cable with shielding is known as shielded twisted pair (STP) and without as unshielded twisted pair (UTP). Explanation A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twisting ensures that the two wires are on ave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Openreach
Openreach Limited is a company wholly owned by BT Group plc, that maintains the telephone cables, ducts, cabinets and exchanges that connect nearly all homes and businesses in the United Kingdom to the national broadband and telephone network. It was established in 2006 following an agreement between BT and the UK's telecoms regulator, Ofcom, to implement certain undertakings, pursuant to the Enterprise Act 2002, to ensure that rival telecom operators have equality of access to BT's local network. Openreach manages BT's local access network which connects customers to their local telephone exchange, starting at the main distribution frame (MDF) in the exchange and ending at the network termination point (NTP) at the end user's premises. Openreach also manages the connections between the MDF and the BT Wholesale/local-loop unbundling (LLU) termination points located in the exchange, often referred to as jumper connections. In March 2017, after various negotiations with, and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgin Media
Virgin Media is a British telecommunications company which provides telephone, Cable television, television and Internet access, internet services in the United Kingdom. Its headquarters are at Green Park in Reading, Berkshire, Reading, England. It is owned by Virgin Media O2, a 50:50 joint venture between Liberty Global and Telefónica. Virgin Media owns and operates its own optical fiber, fibre-optic cable television, cable network in the United Kingdom, although in most areas optical fibre does not reach customer premises, instead going to a nearby street cabinet to provide a fibre to the cabinet service. As of 31 December 2012, it had a total of approximately 4.8 million cable customers, of whom around 3.79 million were supplied with its television services (Virgin TV), around 4.2 million with broadband internet services and around 4.1 million with fixed-line telephony services. At the same date, it had around 3 million mobile telephony customers. Since the acquisition of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serving Area Interface
The serving area interface or service area interface (SAI) is an outdoor enclosure or metal box that allows access to telecommunications wiring. Alternate names *Access point (AP) *Cabinet (cab) *B-box (breakout box) *Cross box *Cross-connect box *Jumper wire interface (JWI) *Outside plant interface (OPI) *Pedestal (ped) *Primary cross-connection point (PCP) (UK)"Multimedia Telecommunications" (BT Telecommunications Series), B. Whyte (Ed.), Springer 1997 *Secondary cross-connection point (SCP) (UK) *Telecom cabinet Function The SAI provides the termination of individual twisted pairs of a telephony local loop for onward connection back to the nearest telephone exchange (US: " central office" (CO)) or remote switch, or first to transmission equipment such as a subscriber loop carrier multiplexer and then to the exchange main distribution frame (MDF). In the United Kingdom, the components from the PCP onwards to the customer are known as "D-side" (distribution side), and from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cable Fault Location
Cable fault location is the process of locating periodic faults, such as insulation faults in cables. In this process, mobile shock discharge generators are among the devices used. Cable faults Cable faults are damage to cables which effect a resistance in the cable. If allowed to persist, this can lead to a voltage breakdown. There are different types of cable faults, which must first be classified before they can be located. The insulation of the cable plays a significant role in this. While paper-impregnated cables are particularly susceptible to external chemical and thermal influences, in high-voltage PE or XLPE cables the polyethylene insulation of the conductor is affected, leading to partial breakdowns and cracks that “eat away” the insulation. Screening faults A contact between conductor and screen generates a varying resistance. Phase faults The contact between multiple conductors generates a varying resistance. Sheath faults Sheath faults are damage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Networks
Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics * Networks, a graph with attributes studied in network theory ** Scale-free network, a network whose degree distribution follows a power law ** Small-world network, a mathematical graph in which most nodes are not neighbors, but have neighbors in common * Flow network, a directed graph where each edge has a capacity and each edge receives a flow Biology * Biological network, any network that applies to biological systems * Ecological network, a representation of interacting species in an ecosystem * Neural network, a network or circuit of neurons Technology and communication * Artificial neural network, a computing system inspired by animal brains * Broadcast network, radio stations, television stations, or other electronic media outlets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Telephone Exchange")
