 | This article needs additional citations for verification .(January 2021) |
A cable landing point is the location where a submarine or other underwater cable makes landfall. The term is most often used for the landfall points of submarine telecommunications cables and submarine power cables. The landing will either be direct (in the case of a point-to-point cable system) or via a branch from a main cable using a submarine branching unit. The branch can be several kilometres long.
Cable landing points are usually carefully chosen to be in areas:
Such locations are rare, and will usually be the shared landfall point for several cable systems.
Frequently, there will be a nearby cable landing station, or cable termination station, which may well be shared between multiple cable systems, but in some cases, the cable may be laid many miles inland before reaching its termination point.
A cable landing station may or may not be required, depending on whether, for example, the submarine cable requires power in order to provide power to submarine repeaters or amplifiers. The voltages applied to the cables can be high—3,000 to 4,000 volts for a typical trans-Atlantic telecommunications cable system, and 1,000 volts for a cross-channel telecommunications cable system. Submarine power cables can operate at many kilovolts: for example, the Fenno-Skan power cable operates at 400 kV DC.
A cable termination station is the point at which the submarine cable connects into the land-based infrastructure or network. A cable termination station may be the same facility as the cable landing station, or may be many miles away. The termination station will usually be the point where high-capacity 'backhaul' land-based network connects to areas of high demand, which are usually centres of high population density, rather than the usually remote locations of cable landing points/landing stations/termination stations. A good example of this is the Endeavour cable system which connects Australia to Hawaii. The cable landing point in Sydney is Tamarama Beach, some distance from the cable termination station in Paddington.
For power cables the term cable termination station is not strictly determined. It is either the point where the underwater cable ends and where the overhead powerline starts or if the whole line is implemented as cable, the first cable sleeve on the land. However one can also say that the substation or HVDC static inverter plant, where the connection to the grid is made describe as cable termination station. However, this station can be far away from the coast.
Though Guam is a United States territory, some U.S. long-distance plans and courier services list Guam as an international location. As a result of Guam's being added to the North American Numbering Plan (NANP) in 1997, calls made to the U.S., Canada, or other participating countries from Guam only require the caller to dial a 1 followed by the area code.
TAT-14 was the 14th consortium transatlantic telecommunications cable system. In operation from 2001 to 2020, it used wavelength division multiplexing. The cable system was built from multiple pairs of fibres—one fibre in each pair was used for data carried in one direction and the other in the opposite direction. Although optical fibre can be used in both directions simultaneously, for reliability it is better not to require splitting equipment at the end of the individual fibre to separate transmit and receive signals—hence a fibre pair is used. TAT-14 used four pairs of fibres—two pairs as active and two as backup. Each fibre in each pair carried 16 wavelengths in one direction, and each wavelength carried up to an STM-256. The fibres were bundled into submarine cables connecting the United States and the European Union in a ring topology.
A transatlantic telecommunications cable is a submarine communications cable connecting one side of the Atlantic Ocean to the other. In the 19th and early 20th centuries, each cable was a single wire. After mid-century, coaxial cable came into use, with amplifiers. Late in the 20th century, all cables installed used optical fiber as well as optical amplifiers, because distances range thousands of kilometers.
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.
A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems.
Until January 1, 2007, Blaabjerg was a municipality in Ribe County on the west coast of the Jutland peninsula in southwest Denmark. The municipality covered an area of 254 km2, and had a total population of 6,509 (2005). Its latest mayor was Preben Olesen. The site of its municipal council was the town of Nørre Nebel.
The Baltic Cable is a monopolar HVDC power line running beneath the Baltic Sea that interconnects the electric power grids of Germany and Sweden. Its maximum transmission power is 600 megawatts (MW).
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, contraspiralling wire strands or both. A longitudinal wire may be necessary with dielectric spiral foils to short out each turn.
In telecommunications, structured cabling is building or campus cabling infrastructure that consists of a number of standardized smaller elements called subsystems. Structured cabling components include twisted pair and optical cabling, patch panels and patch cables.
A submarine power cable is a transmission cable for carrying electric power below the surface of the water. These are called "submarine" because they usually carry electric power beneath salt water but it is also possible to use submarine power cables beneath fresh water. Examples of the latter exist that connect the mainland with large islands in the St. Lawrence River.
Extra-low voltage (ELV) is an electricity supply voltage and is a part of the Low voltage band in a range which carries a low risk of dangerous electrical shock. There are various standards that define extra-low voltage. The International Electrotechnical Commission (IEC) and the UK IET define an ELV device or circuit as one in which the electrical potential between two conductors or between an electrical conductor and earth (ground) does not exceed 50 V AC or 120 V DC.
In a hierarchical telecommunications network, the backhaul portion of the network comprises the intermediate links between the core network, or backbone network, and the small subnetworks at the edge of the network.
VSNL Northern Europe is a telecommunications cable system with both submarine and terrestrial parts, connecting England and the Netherlands.
Gondwana-1 is a submarine communications cable network connecting New Caledonia and Australia brought into service in mid-2008.
The West Africa Cable System (WACS) is a submarine communications cable linking South Africa with the United Kingdom along the west coast of Africa that was constructed by Alcatel-Lucent. The cable consists of four fibre pairs and is 14,530 km in length, linking from Yzerfontein in the Western Cape of South Africa to London in the United Kingdom. It has 14 landing points, 12 along the western coast of Africa and 2 in Europe completed on land by a cable termination station in London. The total cost for the cable system is $650 million. WACS was originally known as the Africa West Coast Cable (AWCC) and was planned to branch to South America but this was dropped and the system eventually became the West African Cable System.
The MONET cable system is a subsea fibre optic telecommunications cable completed in December 2017. Final splicing occurred in November 2016. Monet connects the cities of Praia Grande and Fortaleza in Brazil with Boca Raton in the United States.
NJFX, also known as New Jersey Fiber Exchange, is a Wall Township, NJ-based data center and subsea cable landing station operator. The company offers Tier 3 data center, meet-me room and colocation services, and a cable landing station on a 58 acre campus.
Havfrue (Mermaid) is a submarine communications cable privately owned by Aqua Comms, Facebook, Google and Bulk Infrastructure, linking the United States, Ireland and Denmark.
Submarine rescue is the process of locating a sunk submarine with survivors on board, and bringing the survivors to safety. This may be done by recovering the vessel to the surface first, or by transferring the trapped personnel to a rescue bell or deep-submergence rescue vehicle to bring them to the surface. Submarine rescue may be done at pressures between ambient at depth, and sea level atmospheric pressure, depending on the condition of the distressed vessel and the equipment used for the rescue. Self-rescue of submarine personnel by buoyant free ascent at ambient pressure is considered submarine escape. Survivors may require recompression treatment for decompression illness.