Transatlantic telephone cable

From Wikipedia, the free encyclopedia

A transatlantic telephone cable is a submarine communications cable that carries telephone traffic under the Atlantic Ocean.

When the first transatlantic telegraph cable was laid in 1858 by businessman Cyrus West Field, it operated for only a month; 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 (Transatlantic No. 1) was the first submarine transatlantic telephone cable system. It was laid between Gallanach Bay, near Oban, Scotland and Clarenville, Newfoundland between 1955 and 1956. It was inaugurated on September 25, 1956, initially carrying 36 telephone channels. In the first 24 hours of public service there were 588 London-US calls and 119 from London to Canada. The capacity of the cable was soon increased to 48 channels. TAT-1 was finally retired in 1978.

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 cables.

Cable Name Date(s) in service Type Initial No. of channels Final No. of channels Western end Eastern end
TAT-1 1956-1978 Galvanic 36 48 Newfoundland Scotland
TAT-2 1959-1982 Galvanic 48 72 Newfoundland France
TAT-3 1963-1986 Galvanic 138 276 New Jersey England
TAT-4 1965-1987 Galvanic 138 345 New Jersey France
TAT-5 1970-1993 Galvanic 845 2112 Rhode Island Spain
TAT-6 1976-1994 Galvanic 4,000 10,000 Rhode Island France
TAT-7 1978-1994 Galvanic 4,000 10,500 New Jersey England
TAT-8* 1988-2002 Fiber-optic 40,000 - USA England, France
TAT-9 1992-2004 Fiber-optic 80,000 - USA, Nova Scotia Spain, France, United Kingdom
TAT-10 1992-2003 Fiber-optic 2 x 565 Mbit/s - USA Germany
TAT-11 1993-2003 Fiber-optic 2 x 565 Mbit/s - USA France
TAT-12/13 1996- Fiber-optic 12 x 2.5 Gbit/s - USA x 2 United Kingdom, France
TAT-14 2000- Fiber-optic 64 x 10 Gbit/s - USA x 2 United Kingdom, France, Netherlands, Germany, Denmark
CANTAT-1 1961-1986 Galvanic 80 - Newfoundland Scotland
CANTAT-2 1974-1992 Galvanic 1,840 - Nova Scotia England
CANTAT-3 1994- Fiber-optic 2 x 2.5 Gbit/s Nova Scotia Iceland, Faroe Islands, England, Denmark, Germany
PTAT-1 1989-2004 Fiber-optic 3 x 140 Mbit/s? New Jersey & Bermuda Ireland & United Kingdom

* first fiber optic cable.

The TAT series of cables constitute a large percentage of all north Atlantic cables. All TAT cables are consortia joint ventures between a number of telecommunications companies, e.g. British Telecom. CANTAT are Transatlantic Telephone cables terminating in Canada rather than the USA. There are a number of private non-TAT cables.

Cable name Date(s) Nominal Capacity Owner
Gemini (decommissioned) 1998   Cable & Wireless
Apollo 2002 3.2 Tbit/s Cable & Wireless
AC-1 1998 120 Gbit/s Global Crossing
Yellow/AC-2 2000   Level 3
FLAG Atlantic 2000   Reliance Communications
VSNL Transatlantic 2001 5.1 Tbit/s sold by Tyco to VSNL in 2005
Hibernia Atlantic 2001 320 Gbit/s CVC Acquisition Company

[edit] Other Atlantic cables

SAT-2, SAT-3/WASC/SAFE, ATLANTIS-2, COLUMBUS III.

[edit] See also

[edit] External links