|
Terrestrial Cable
__NOTOC__ A terrestrial cable is a communications cable which crosses land, rather than water. Terrestrial cable may be subterranean (buried) or aerial (suspended from poles), and may be fiber or copper. The term "terrestrial cable" is principally used to distinguish it from submarine cable, although some overlap exists between the two. Major terrestrial cable systems include the Europe-Persia Express Gateway and the family of Eurasia terrestrial cable networks. See also * Aerial cable * Utility pole * Undergrounding * Direct-buried cable * List of terrestrial fibre optic cable projects in Africa This is a list of terrestrial fibre optic cable projects in Africa. While submarine communications cables are used to connect countries and continents to the Internet, terrestrial fibre optic cables are used to extend this connectivity to landl ... References External links Eurasia terrestrial cable networksThe Operation of Cross-Border Terrestrial Fibre-Optic Networks in A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Line
In electrical engineering, a transmission line is a specialized cable or other structure designed to conduct electromagnetic waves in a contained manner. The term applies when the conductors are long enough that the wave nature of the transmission must be taken into account. This applies especially to radio-frequency engineering because the short wavelengths mean that wave phenomena arise over very short distances (this can be as short as millimetres depending on frequency). However, the theory of transmission lines was historically developed to explain phenomena on very long telegraph lines, especially submarine telegraph cables. Transmission lines are used for purposes such as connecting radio transmitters and receivers with their antennas (they are then called feed lines or feeders), distributing cable television signals, trunklines routing calls between telephone switching centres, computer network connections and high speed computer data buses. RF engineers commonly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Cable
An aerial cable or air cable is an insulated cable usually containing all conductors required for an electrical distribution system (typically using aerial bundled cables) or a telecommunication line, which is suspended between utility poles or electricity pylons. As aerial cables are completely insulated there is no danger of electric shock when touching them and there is no requirement for mounting them with insulators on pylons and poles. A further advantage is they require less right of way than overhead lines for the same reason. They can be designed as shielded cables for telecommunication purposes. If the cable falls, it may still operate if its insulation is not damaged. As aerial cables are installed on pylons or poles, they may be cheaper to install than underground cables, as no work for digging is required, which can be very expensive in rocky areas. Use Aerial cables are mostly used for telecommunication systems or for power transmissions with voltages bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility Pole
A utility pole is a column or post typically made out of wood used to support overhead power lines and various other public utilities, such as electrical cable, optical fiber, fiber optic cable, and related equipment such as Distribution transformer, transformers and street lights. It can be referred to as a transmission pole, telephone pole, telecommunication pole, power pole, hydro pole, telegraph pole, or telegraph post, depending on its application. A Stobie pole is a multi-purpose pole made of two steel joists held apart by a slab of concrete in the middle, generally found in South Australia. Electrical wires and cables are routed overhead on utility poles as an inexpensive way to keep them insulated from the ground and out of the way of people and vehicles. Utility poles can be made of wood, metal, concrete, or composites like fiberglass. They are used for two different types of power lines: ''sub transmission lines'', which carry higher voltage power between substations, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiber-optic Cable
A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable is used. Different types of cable are used for different applications, for example, long distance telecommunication, or providing a high-speed data connection between different parts of a building. Design Optical fiber consists of a core and a cladding layer, selected for total internal reflection due to the difference in the refractive index between the two. In practical fibers, the cladding is usually coated with a layer of acrylate polymer or polyimide. This coating protects the fiber from damage but does not contribute to its optical waveguide properties. Individual coated fibers (or fibers formed into ribbons or bundles) then have a tough ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper Conductor
Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor. Copper is the electrical conductor in many categories of electrical wiring.Pops, Horace, 2008, Processing of wire from antiquity to the future, Wire Journal International, June, pp 58-66 Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Copper and its alloys are also used to make electrical contacts. Electrical wiring in buildings is the most important market for the copper industry. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors. Properties of copper Electrical conductivity Electrical conductivity is a measure of how well a material transports an electric charge. This is an essential property i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Communications Cable
A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables laid beginning in the 1850s carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858. Subsequent generations of cables carried telephone traffic, then data communications traffic. Modern cables use optical fibre technology to carry digital data, which includes telephone, Internet and private data traffic. Modern cables are typically about in diameter and weigh around for the deep-sea sections which comprise the majority of the run, although larger and heavier cables are used for shallow-water sections near shore. Submarine cables first connected all the world's continents (except Antarctica) when Java was connected to Darwin, Northern Terr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe-Persia Express Gateway
On June 8, 2011, a consortium of four leading telecom carriers from four countries signed the Construction and Maintenance Agreement for the new cable system — Europe-Persia Express Gateway (EPEG). The EPEG will be a brand new high capacity fiber optic cable system which links Europe with the Middle East and a possibility of further extension to Persian Gulf regional countries and the Indian subcontinent. The system will pass from Frankfurt across Eastern Europe, Russia, Azerbaijan, Iran and Persian Gulf to Barka, Sultanate of Oman. EPEG members Cable & Wireless, Rostelecom, Omantel Oman Telecommunications Company (Omantel) is the first telecommunications company in Oman and is the primary provider of internet services in the country. The government of Oman owns a 51% share in Omantel. Omantel acquired 65% of WorldCall Pakist ..., and TIC ( Telecommunication Infrastructure Company of I.R.Iran) will build and develop part of the network which operates through their own country. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Cable
An aerial cable or air cable is an insulated cable usually containing all conductors required for an electrical distribution system (typically using aerial bundled cables) or a telecommunication line, which is suspended between utility poles or electricity pylons. As aerial cables are completely insulated there is no danger of electric shock when touching them and there is no requirement for mounting them with insulators on pylons and poles. A further advantage is they require less right of way than overhead lines for the same reason. They can be designed as shielded cables for telecommunication purposes. If the cable falls, it may still operate if its insulation is not damaged. As aerial cables are installed on pylons or poles, they may be cheaper to install than underground cables, as no work for digging is required, which can be very expensive in rocky areas. Use Aerial cables are mostly used for telecommunication systems or for power transmissions with voltages bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undergrounding
In civil engineering, undergrounding is the replacement of overhead cables providing electrical power or telecommunications, with underground cables. It helps in wildfire prevention and in making the power lines less susceptible to outages during high winds, thunderstorms or heavy snow or ice storms. An added benefit of undergrounding is the aesthetic quality of the landscape without the powerlines. Undergrounding can increase the capital cost of electric power transmission and distribution but may decrease operating costs over the lifetime of the cables. History Early undergrounding had a basis in the detonation of mining explosives and in undersea telegraph cables. Electric cables were used in Russia to detonate mining explosives in 1812, and to carry telegraph signals across the English Channel in 1850. With the spread of early electrical power systems, undergrounding began to increase as well. Thomas Edison used underground DC “street pipes” in his early distributio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct-buried Cable
Direct-buried cable (DBC) is a kind of communications or transmissions electrical cable which is especially designed to be buried under the ground without any other cover, sheath, or duct to protect it. Most direct-buried cable is built to specific tolerances to heat, moisture, conductivity, and soil acidity. Unlike standard telecommunications and power cables, which have only a thin layer of insulation and a waterproof outer cover, DBC consists of multiple layers of heavy metallic-banded sheathing, reinforced by heavy rubber covers, shock absorbing gel, wrapped thread-fortified waterproof tape, and stiffened by a heavy metal core. DBC is preferable in some areas since it is more resistant to being the focus of lightning discharges. Communications Most cable of this kind is coaxial or bundled fiber-optic cable. In the 20th century much of it was filled cable. Direct-buried cable is cheaper and easier to lay than other kinds of cable that require protection from the earth. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Terrestrial Fibre Optic Cable Projects In Africa
This is a list of terrestrial fibre optic cable projects in Africa. While submarine communications cables are used to connect countries and continents to the Internet, terrestrial fibre optic cables are used to extend this connectivity to landlocked countries or to urban centers within a country that has submarine cable access. In most of the world, a large number of such cables exist, often amounting to robust Internet backbones. The lack of such high-speed cables poses a great problem for most African countries. The construction of both submarine cables and their terrestrial extensions is thus considered an important step to economic growth and development to many African countries. Countries Algeria Angola Benin Botswana Burkina Faso Burundi Cameroon Chad Cote d'Ivoire Democratic Republic of Congo Djibouti Egypt eSwatini Ethiopia Gambia Ghana Guinea Kenya Liberia Madagascar Malawi Mali Mauritania Morocco Mozambique Namibia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Cables
A shielded cable or screened cable is an electrical cable that has a common conductive layer around its conductors for electromagnetic shielding. This shield is usually covered by an outermost layer of the cable. Common types of cable shielding can most broadly be categorized as foil type (hereunder: metallised film Metallised films (or metallized films) are polymer films coated with a thin layer of metal, usually aluminium. They offer the glossy metallic appearance of an aluminium foil at a reduced weight and cost. Metallised films are widely used for decorati ...), contraspiralling wire strands (braided or unbraided) or both. A longitudinal wire may be necessary with dielectric spiral foils to short out each turn. The shield acts as a Faraday cage – a surface that reflects electromagnetic radiation. This reduces both the Electromagnetic interference, interference from outside noise onto the signals and the signals from radiating out and potentially disturbing other devices ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Direct-buried Cable")