Transatlantic communications cable


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 century, all used optical fiber, and most now use optical amplifiers.

History

When the first transatlantic telegraph cable was laid in 1858 by Cyrus West Field, it operated for only three weeks; subsequent attempts in 1865 and 1866 were more successful. Although a telephone cable was discussed starting in the 1920s, to be practical, it needed a number of technological advances which did not arrive until the 1940s. Starting in 1927, transatlantic telephone service was radio-based.
TAT-1 was the first transatlantic telephone cable system. It was laid between Gallanach Bay, near Oban, Scotland and Clarenville, Newfoundland between 1955 and 1956 by the cable ship Monarch. It was inaugurated on September 25, 1956, initially carrying 36 telephone channels. In the first 24 hours of public service, there were 588 London–U.S. calls and 119 from London to Canada. The capacity of the cable was soon increased to 48 channels. Later, an additional three channels were added by use of C Carrier equipment. Time-assignment speech interpolation was implemented on the TAT-1 cable in June 1960 and effectively increased the cable's capacity from 37 to 72 speech circuits. TAT-1 was finally retired in 1978. Later coaxial cables, installed through the 1970s, used transistors and had higher bandwidth. The Moscow–Washington hotline was initially connected through this system.

Current technology

All cables presently in service use fiber optic technology. Many cables terminate in Newfoundland and Ireland, which lie on the great circle route from London, UK to New York City, US.
There have been a succession of newer transatlantic cable systems. All recent systems have used fiber optic transmission, and a self-healing ring topology. Late in the 20th century, communications satellites lost most of their North Atlantic telephone traffic to these low-cost, high-capacity, low-latency cables. This advantage only increases over time, as tighter cables provide higher bandwidth – the 2012 generation of cables drop the transatlantic latency to under 60 milliseconds, according to Hibernia Atlantic, deploying such a cable that year.
Some new cables are being announced on the South Atlantic: SACS and SAex.

TAT cable routes

The TAT series of cables constitute a large percentage of all North Atlantic cables. All TAT cables are joint ventures between a number of telecommunications companies, e.g. British Telecom. CANTAT cables terminate in Canada rather than in the US.
NameIn serviceTypeInitial channelsFinal channelsWestern endEastern end
TAT-11956–1978Galvanic3651NewfoundlandScotland
TAT-21959–1982Galvanic4872NewfoundlandFrance
TAT-31963–1986Galvanic138276New JerseyEngland
TAT-41965–1987Galvanic138345New JerseyFrance
TAT-51970–1993Galvanic8452,112Rhode IslandSpain
TAT-61976–1994Galvanic4,00010,000Rhode IslandFrance
TAT-71978–1994Galvanic4,00010,500New JerseyEngland
TAT-81988–2002Fiber-optic40,000–New JerseyEngland, France
TAT-91992–2004Fiber-optic80,000–New Jersey, Nova ScotiaSpain, France, England
TAT-101992–2003Fiber-optic2 × 565 Mbit/s–USGermany, Netherlands
TAT-111993–2003Fiber-optic2 × 565 Mbit/s–New JerseyFrance
TAT-12/131996–2008Fiber-optic12 × 2.5 Gbit/s–US × 2England, France
TAT-142001–Fiber-optic3.2 Tbit/s–New Jersey × 2England, France, Netherlands, Germany, Denmark
CANTAT-11961–1986Galvanic80–NewfoundlandEngland
CANTAT-21974–1992Galvanic1,840–Nova ScotiaEngland
CANTAT-31994–2010Fiber-optic2 × 2.5 Gbit/sNova ScotiaIceland, Faroe Islands, England, Denmark, Germany
PTAT-11989–2004Fiber-optic3 × 140 Mbit/s?New Jersey & BermudaIreland & England

Private cable routes

There are a number of private non-TAT cables.
Cable nameReady for serviceCable length Nominal capacityLatency Landing pointsOwner
Gemini May 1998under 100 msnorth: Charlestown, US-RI; Oxwich Bay, GB-WLS; south: Manasquan, US-NJ; Porthcurno, GB-ENGVodafone
AC-1May 199814,301 km120 Gbit/s65 msBrookhaven, US-NY; Whitesands Bay, GB-ENG; Beverwijk, NL-NH; Sylt, DE-SHLevel 3 Communications
Columbus IIIDecember 19999,833 kmHollywood, US-FL; Ponta Delgada, PT; Carcavelos, PT; Conil de la Frontera, ES-AN; Mazara del Vallo, ITvarious telecom operators
Yellow/AC-2September 20007,001 km640 Gbit/sunder 100 msBellport, US-NY; Bude, GB-ENGLevel 3 Communications
Hibernia AtlanticApril 200112,200 km320 Gbit/s, upgraded to 10.16 Tbit/s59 msLynn, US-MA; Herring Cove, CA-NS; Dublin, IE-L; Southport, GB-ENG; Coleraine, GB-NIRGTT Communications, Inc.
FLAG AtlanticJune 200114,500 kmunder 100 msIsland Park, US-NY; Plerin, FR-BRE; Skewjack, GB-ENG; Northport, US-NYGlobal Cloud Xchange
Tata TGN-AtlanticJune 200113,000 km5.1 Tbit/sunder 100 msWall Township, US-NJ; Highbridge, GB-ENGSold by Tyco to Tata Communications in 2005
ApolloFebruary 200313,000 km3.2 Tbit/sunder 100 msManasquan, New Jersey, US-NJ; Lannion, FR-BRE; Bude, GB-ENG; Shirley, US-NYVodafone
Greenland ConnectMarch 20094,780 kmMilton, CA-NL; Aasiaat, GL-QA; Sisimiut, GL-QE; Maniitsoq, GL-QE; Nuuk, GL-SM; Qaqortoq, GL-KU; Landeyjar, ISTELE Greenland
Hibernia ExpressSeptember 20154,600 kmHalifax, CA-NS; Cork, IE-M; Brean, GB-ENGGTT Communications, Inc.
AEConnectJanuary 20165,522 km4 × 10 Tbit/s 54 msShirley, US-NY; Killala, IE-C
MAREAFebruary 20186,600 km160 Tbit/sVirginia Beach, US-VA; Bilbao, ES-PVFacebook, Microsoft, Telefónica
MidgardsormenQ2 2019 7,848 kmVirginia Beach, US-VA; Blaabjerg, DK; Mo i Rana, NO
DunantQ3 2020 6,400km250 Tbit/sVirginia Beach, US-VA; Saint-Hilaire-de-Riez, FRGoogle

South Atlantic cable routes

Cable nameReady for serviceLengthLanding pointsOwner
Atlantis-2February 20008,500 kmCarcavelos, PT; El Médano, ES-CN; Praia, CV; Dakar, SN; Fortaleza, BR-CE; Las Toninas, AR-Bvarious telecom operators
EulaLinkQ1 20185,900 kmSines, PT; Fortaleza, BR-CE; Santos, BR-SPTelebras, IslaLink
SAexQ2 201813,050 kmVirginia Beach, US-VA; Jamestown, SH-HL; Yzerfontein, ZA-WC; Mtunzini, ZA-NLSAEx International Ltd.
SACSQ3 20186,165 kmFortaleza, BR-CE; Luanda, AOAngola Cables
SAILQ4 20185,900 kmFortaleza, BR-CE; Kribi, CMCamtel, China Unicom