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.
Contents
History
When the first transatlantic telegraph cable was laid in 1858 by businessman Cyrus West Field, it operated for only three weeks; subsequent attempts in 1865 and 1866 were more successful.[1] Although a telephone cable was discussed starting in the 1920s[citation needed], to be practical it needed a number of technological advances which did not arrive until the 1940s[citation needed]. Starting in 1927, transatlantic telephone service was radio-based.[2]
TAT-1 (Transatlantic No. 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.[3] 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 (TASI) was implemented on the TAT-1 cable in June 1960 and effectively increased the cable's capacity from 37 (out of 51 available channels) to 72 speech circuits. TAT-1 was finally retired in 1978. Later coaxial cables, installed through the 1970s, used transistors and had higher bandwidth.
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 (the shortest route) from London, UK to New York City, USA.
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 speed – the 2012 generation of cables drop the transatlantic latency to under 60 milliseconds, according to Hibernia Atlantic, deploying such a cable that year.[4][5]
Some new cables are being announced on the South Atlantic: SACS(South Atlantic Cable System)[6] and SAex(South Atlantic Express) [7]
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 USA.
| Name | In service | Type | Initial channels | Final channels | Western end | Eastern end |
|---|---|---|---|---|---|---|
| TAT-1 | 1956–1978 | Galvanic | 36 | 51 | Newfoundland | United Kingdom |
| TAT-2 | 1959–1982 | Galvanic | 48 | 72 | Newfoundland | France |
| TAT-3 | 1963–1986 | Galvanic | 138 | 276 | New Jersey | United Kingdom |
| TAT-4 | 1965–1987 | Galvanic | 138 | 345 | New Jersey | France |
| TAT-5 | 1970–1993 | Galvanic | 845 | 2,112 | 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 | United Kingdom |
| TAT-8 | 1988–2002 | Fiber-optic | 40,000 | – | USA | United Kingdom, France |
| TAT-9 | 1992–2004 | Fiber-optic | 80,000 | – | USA, Nova Scotia | Spain, France, United Kingdom |
| TAT-10 | 1992–2003 | Fiber-optic | 2 × 565 Mbit/s | – | USA | Germany, Netherlands |
| TAT-11 | 1993–2003 | Fiber-optic | 2 × 565 Mbit/s | – | USA | France |
| TAT-12/13 | 1996–2008 | Fiber-optic | 12 × 2.5 Gbit/s | – | USA × 2 | United Kingdom, France |
| TAT-14 | 2001– | Fiber-optic | 3.2 Tbit/s | – | USA × 2 | United Kingdom, France, Netherlands, Germany, Denmark |
| CANTAT-1 | 1961–1986 | Galvanic | 80 | – | Newfoundland | United Kingdom |
| CANTAT-2 | 1974–1992 | Galvanic | 1,840 | – | Nova Scotia | United Kingdom |
| CANTAT-3 | 1994–2010 | Fiber-optic | 2 × 2.5 Gbit/s | Nova Scotia | Iceland, Faroe Islands, United Kingdom, Denmark, Germany | |
| PTAT-1 | 1989–2004 | Fiber-optic | 3 × 140 Mbit/s? | New Jersey & Bermuda | Ireland & United Kingdom |
Private cable routes
There are a number of private non-TAT cables.
| Cable name | Date(s) | Nominal capacity | Latency (ms) | Landings | Owner |
|---|---|---|---|---|---|
| Gemini (decommissioned) | 1998 | Under 100 ms | Vodafone (originally Cable & Wireless) | ||
| Apollo | 2002 | 3.2 Tbit/s | Under 100 ms | Vodafone/Alcatel-Lucent (originally Cable & Wireless)[8] | |
| AC-1 | 1998 | 120 Gbit/s | 65 ms[5] | Level 3 Communications (originally Global Crossing) | |
| Yellow/AC-2 | 2000 | 640 Gbit/s | Under 100 ms | Level 3 Communications | |
| FLAG Atlantic | 2000 | Under 100 ms | Reliance Communications | ||
| VSNL Transatlantic | 2001 | 5.1 Tbit/s | Under 100 ms | Sold by Tyco to VSNL in 2005 | |
| Hibernia Atlantic | 2001 | 320 Gbit/s, upgraded to 10.16 Tbit/s[9] | Under 70 ms | CVC Acquisition Company | |
| Emerald Express | 2014 (scheduled)[10] | 4 × 10 Tbit/s (four strand 100 × 100 Gbit/s) | 54 ms | Moncton; St. John's; Grindavík, Iceland; Belfast; Dublin; Shirley, New York | Emerald Atlantis |
| Hibernia Atlantic | 2012 | Unknown (four strand) | 59 ms[5] | Herring Cove (near Halifax, Canada) | CVC Acquisition Company |
South Atlantic cable routes
| Cable name | Date(s) | Landing | Owner |
|---|---|---|---|
| SACS | 2016 | Luanda; Fortaleza | Angola Cables |
| SAex | 2017 | Mtunzini; Yzerfontein; Saint Helena; Fortaleza | SimplCom South Africa |
See also
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Short-Wave System for Transatlantic Telephony, by Polkinghorn and Schlaack BSTJ, 1935
- ↑ "Being First Telephone Cable to Connect Hemispheres" Popular Mechanics, March 1954, p. 114.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://www.nec.com/en/press/201411/global_20141104_04.html
- ↑ http://www.techcentral.co.za/16tbits-saex-cable-deal-signed/35811/
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- Lua error in package.lua at line 80: module 'strict' not found.
- Aronsson's Telecom History Timeline[dead link]
- Timeline of Submarine Communications Cables, 1850–2008
- Submarine Cable Landings Worldwide
