| 词条 | Fiber-Optic Link Around the Globe |
| 释义 |
|logo = FLAG Telecom logo 2003.gif |logo_caption = Logo from 2003 |foundation = 1999 |industry = Telecommunication |owner = Global Cloud Xchange }}Fiber-Optic Link Around the Globe (FLAG) is a {{convert|28000|km|mi nmi|-1|abbr=off|lk=on}} long fibre optic mostly-submarine communications cable that connects the United Kingdom, Japan, India, and many places in between. The cable is operated by Global Cloud Xchange.[1] The system runs from the eastern coast of North America to Japan.[2] Its Europe-Asia segment was the fourth longest cable in the world in 2008.[3] The Europe-Asia segment was laid by Cable & Wireless Marine in the mid-1990s, and was the subject of an article in Wired magazine in December 1996 by Neal Stephenson.[2] DescriptionThe FLAG cable system was first placed into commercial service in late 1997.[4] FLAG offered a speed of 10 Gbit/s, and uses synchronous digital hierarchy technology. It carries over 120,000 voice channels via {{convert|27000|km|mi nmi|-1|abbr=off|lk=on}} of mostly undersea cable. FLAG uses erbium-doped fiber amplifiers, and was jointly supplied by AT&T Submarine Systems and KDD-Submarine Cable Systems. Its design, development, installation, and service conformed to ISO 9000 quality standards. FLAG provided a link between the European end of high-density transatlantic crossings and the Asian end of the transpacific crossings.[5] FLAG includes undersea cable segments, and two terrestrial crossings. The segments can be either direct point-to-point links, or multipoint links, which are attained through branching units. At each cable landing point, a FLAG cable station is located. The total route length exceeds {{convert|27000|km|mi nmi|-1|abbr=off}}, and comprises {{convert|1020|km|0|abbr=off}} of terrestrial crossings. Approximately {{convert|6600|km|mi nmi|-1|abbr=off}} of the submerged cable is buried {{convert|1|m|0|abbr=off}} below the sea bed. Cable burial was performed by either a submersible plough as the cable was laid, or jetting the laid cable into the sea bed via remotely operated vehicles (ROVs).[5] Over several years, the route evolved as new branches and feeder systems were considered and realised. FLAG includes two terrestrial crossings, one in Egypt, and the other in Thailand. Each of these land crossings is totally duplicated on fully different routes. As a result, any fault within one route will cause automatic protection switching to the other route within a time period of less than 50 ms.[5] Like other global undersea networks, FLAG uses erbium-doped fibre amplifiers (EDFAs). EDFAs boost the optical signals instead of the optical/electrical conversion, which is generally used in regenerative technology. These optical amplifiers use short, gain-specific lengths of fibre which are doped with erbium ions, and spliced in-line with the transmission fibre. The signal power is amplified by pumping the erbium-doped fibre (EDF) with 1,480 nm laser light which is attached through an optical coupler. The majority of the repeater components are passive. These include EDF, fused-fibre optical couplers and optical isolators. Active components include laser pump assemblies, and associated controls. The total number of components within the repeater is lesser than that of regenerative systems.[5] The FLAG terrestrial crossings do not contain repeaters for reliability reasons. The terminal stations in land crossings use optical amplifiers, high performance transmitter / receivers, and forward error correction to cross the large distances without repeaters. Amplification at the terminal output provides output signal power as high as +17 dBm, and optical amplification at the receiver improves the receiver sensitivity as much as 8 dB.[5]{{Clarify|date=March 2014|reason=Exactly what does this mean? Noise floor at +8, no errors at +8, or what? Seems 'deaf'. "As high as" is awkward for a receiver.}} The route between Alexandria and Cairo is {{convert|223|km|0|abbr=off}} long, and hence requires remote pumping in order to meet performance requirements. Remotely pumped amplifiers can be regarded as repeaters without active modules. This technology comprises short lengths of EDF spliced into the land cable. The erbium-doped sections are situated within the cable span, and are pumped by 1,480 nm pump lasers which are based at the station.[5] An upgrade to the network was announced in 2006, when the acronym was expanded to "Fibre Loop Across Globe" (FLAG).[6]{{Clarify|date=March 2014|reason=This doesn't make sense. Expanded from what? It was already FLAG.}} Segments and landing pointsCable landing points are: Europe AsiaFLAG Europe Asia (FEA) was the first segment opened for commercial use on 22 November 1997.[4][7]
AtlanticThe FLAG Atlantic 1 (FA-1) segment became operational in June 2001.[8] It was constructed as a joint venture between a FLAG Atlantic subsidiary of the parent company FLAG Telecom Holdings, and GTS Transatlantic. Alcatel Submarine Networks laid the undersea portion, and the entire cost was estimated at $1.1 billion.[4][9]
In March 2013, an upgrade for the southerly link was announced to up to 100 Gbit/s, with equipment from Ciena.[10] FLAG Alcatel-Lucent Optical NetworkThe FLAG Alcatel-Lucent Optical Network (FALCON) cable system, connecting India and several countries in the Persian Gulf, became operational in September 2006.[11] It has landing points in:[12][13]
There is an additional segment, listed as part of FALCON, but not directly connected. It has landing points in:[12]
In 2006, Kenya Data Networks announced plans for a spur from Yemen to Mombasa.[14] FLAG North Asia Loop / TigerFLAG North Asia Loop (FNAL) / Tiger became operational in stages, with the final stages completed in 2002.[15] The FNAL landing points are:[16]
West of Mumbai, FLAG has a capacity of 80 Gbit/s. The segment between Lantau, Hong Kong, and Busan, South Korea was broken by the 2006 Hengchun earthquake. DisruptionsDecember 2006 and January 2007The 2006 Hengchun earthquake on 26 December 2006, off the southwest coast of Taiwan, disrupted internet services in Asia, affecting many Asian countries. Financial transactions, particularly in the foreign exchange market were seriously affected as well.[17][18] The disruption was caused by damage to several submarine communications cables.[19] January and February 2008{{see also|2008 submarine cable disruption}}On 30 January 2008, internet services were widely disrupted in the Middle East and in the Indian subcontinent following damage to the SEA-ME-WE 4 and FLAG cables in the Mediterranean Sea.[20] BBC News Online reported 70% disruption in Egypt and 60% disruption in India.[21] Problems were reported in Bahrain, Bangladesh, Kuwait, Pakistan, Qatar, Saudi Arabia, and United Arab Emirates.[22] The respective contributions of the two cable systems to this blackout is unclear. Network outage graphs suggest that the two breaks occurred at 04:30 and 08:00 UTC.[23] The cause of the damage was not declared by either cable operator, but news sources speculated the damage was caused by a ship's anchor near Alexandria.[21][24] According to the Agence France-Presse, the Kuwaiti government attributed the breaks to "weather conditions and maritime traffic".[25] The New York Times reported that the damage occurred to the two systems separately near Alexandria and near Marseilles.[26] Egypt knew of "no passing ships" near Alexandria which has restricted waters.[27] One day later, on 1 February 2008, the FALCON cable was also reported cut {{convert|56|km|mi nmi|0|abbr=off}} off Dubai.[28][29] The first of two repair ships was in place by 5 February.[30] December 2008On 19 December 2008, internet services were widely disrupted in the Middle East, and in the Indian subcontinent, following damage to the SEA-ME-WE 4, SEA-ME-WE 3, and FLAG FEA cables in the Mediterranean Sea.[31] It is not known what has caused these multiple breaks, however, there was seismic activity in the Malta area shortly before the breaks were identified,[31] although it is thought that the damage may be due to a ship's anchor or trawler net.[32] According to FEA Cable System of Reliance Globalcom, the failure lay between Alexandria and Palermo. Reliance Globalcom completed the repair on the FLAG EUROPE ASIA (FEA) cable on 29 December 2008, at 14:15 GMT. Customer services that were affected due to the cable cut have been restored back normal with the completion of repairs.[33] August 2009Damage to FNAL caused by Typhoon Morakot was reported as affecting internet traffic to China on 18 August 2009.[34] GCHQ interceptionIn 2014, it was revealed that Skewjack was the location of the Government Communications Headquarters (GCHQ) interception point on the Reliance Communications international fibre link, copying data to GCHQ Bude, as part of GCHQ's Mastering the Internet project.[35][36][37] See also{{Portal|Telecommunications}}
Other cable systems following a substantially similar route to FLAG Europe-Asia (FEA) are:
References1. ^{{Cite web |url=http://www.telecomreviewasia.com/index.php?option=com_content&view=article&id=589:global-cloud-xchange-plans-new-india-singapore-cable&catid=3:newsflash&Itemid=232 |title=Archived copy |access-date=19 December 2014 |archive-url=https://web.archive.org/web/20141219183139/http://www.telecomreviewasia.com/index.php?option=com_content&view=article&id=589:global-cloud-xchange-plans-new-india-singapore-cable&catid=3:newsflash&Itemid=232 |archive-date=19 December 2014 |dead-url=yes |df=dmy-all }} 2. ^1 {{Cite news|title=Mother Earth Mother Board|work=Wired|date=December 1996|author=Neal Stephenson|issue=4.12|url=https://www.wired.com/wired/archive/4.12/ffglass.html|accessdate=5 October 2013}} 3. ^{{Cite news|title=The internet's undersea world|website= |publisher=The Guardian|date=1 February 2008|url=http://image.Guardian.co.uk/sys-images/Technology/Pix/pictures/2008/02/01/SeaCableHi.jpg|accessdate=16 October 2017}} 4. ^1 2 {{Cite web|title=Prospectus|author=FLAG Telecom Holdings|date=16 May 2000|publisher=US Securities and Exchange Commission|url=https://www.SEC.gov/Archives/edgar/data/1102752/000091205700024976/0000912057-00-024976.txt|accessdate=6 October 2013}} 5. ^1 2 3 4 5 {{Cite journal|last=Welsh|first=Thomas|last2=Smith|first2=Roger|last3=Azami|first3=Haruo|last4=Chrisner|first4=Raymond|title=The FLAG cable system|journal=IEEE Communications Magazine|volume=34|issue=2|pages=30–35|date=February 1996|doi=10.1109/35.481241}} 6. ^{{Cite web|title=Fibre Loop Across Globe|work=Promotional slides|date=28 December 2006|publisher=FLAG Telecom|url=http://www.FlagTelecom.com/media/Network%20Files/Flag_Final_Dec28.pdf|deadurl=yes|archiveurl=https://web.archive.org/web/20070317035922/http://www.FlagTelecom.com/media/Network%20Files/Flag_Final_Dec28.pdf|archivedate=17 March 2007|accessdate=5 October 2013}} 7. ^Coverage map > cable systems > FEA {{Webarchive|url=https://web.archive.org/web/20140322132108/http://www.relianceglobalcom.com/RGCOM_CoverageMap.html |date=22 March 2014 }}, Reliance Globalcom. 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blog|publisher=Renesys|archiveurl=https://web.archive.org/web/20080203133228/http://www.renesys.com/blog/2008/01/mediterranean_cable_break_1.shtml#more|archivedate=3 February 2008|deadurl=yes|df=dmy-all}} 24. ^{{Cite news|title=Cable damage hits internet connectivity|publisher=The Times of India|accessdate=31 January 2008|date=31 January 2008|website=TimesOfIndia.IndiaTimes.com|url=http://articles.TimesOfIndia.IndiaTimes.com/2008-01-31/india/27757001_1_cable-damage-hits-internet-undersea-cables-internet-users}} 25. ^{{Cite news|title=Indian outsourcing sector hit by internet disruption|work=AFP|accessdate=31 January 2008|date=31 January 2008|url=https://afp.Google.com/article/ALeqM5gadarOY4frbM-XSyXS0_wMfxpHig|deadurl=yes|archiveurl=https://web.archive.org/web/20080203184552/http://afp.google.com/article/ALeqM5gadarOY4frbM-XSyXS0_wMfxpHig|archivedate=3 February 2008|df=dmy-all}} 26. ^{{Cite news|issn=0362-4331|last=Timmons|first=Heather|title=2 communication cables in the mediterranean are cut|work=The New York Times|accessdate=31 January 2008|date=31 January 2008|url=https://www.nytimes.com/2008/01/31/business/worldbusiness/31cable.html?ref=business}} 27. ^{{cite news|author=Brauer, David|title=High-tech mystery: are terrorists behind recent internet disruptions?|url=http://www.MinnPost.com/stories/2008/02/04/771/high-tech_mystery_are_terrorists_behind_recent_internet_disruptions|website=MinnPost.com|publisher=MinnPost|date=4 February 2008|accessdate=4 February 2008}} 28. ^{{Cite news|title=Update on submarine cable cut|work=Daily Bulletin|publisher=Flag Telecom|date=6 February 2008|url=http://www.FlagTelecom.com/index.cfm?channel=4328&NewsID=27492|deadurl=yes|archiveurl=https://web.archive.org/web/20080219061824/http://www.FlagTelecom.com/index.cfm?channel=4328&NewsID=27492|archivedate=19 February 2008|accessdate=5 October 2013}} 29. ^{{cite news|url=http://edition.CNN.com/2008/WORLD/meast/02/01/internet.outage/index.html|work=CNN|title=Third undersea internet cable cut in mideast|date=1 February 2008|accessdate=2 May 2010}} 30. ^{{Cite news|title=Work begins to repair severed net|date=5 February 2008|website=news.BBC.co.uk|publisher=BBC News|url=http://news.BBC.co.uk/2/hi/technology/7228315.stm|accessdate=5 October 2013}} 31. ^1 {{cite news|title=Severed cable disrupts net access|website=news.BBC.co.uk|publisher=BBC News|date=19 December 2008|url=http://news.BBC.co.uk/1/hi/technology/7792688.stm|accessdate=21 December 2008}} 32. ^{{cite news|title=Third subsea cable repairs begin|website=news.BBC.co.uk|publisher=BBC News|date=23 December 2008|url=http://news.BBC.co.uk/1/hi/technology/7797162.stm|accessdate=27 December 2008}} 33. ^{{Cite web |url=http://www.iglobalcom.relianceglobalcom.com/iglobalcom/cableupdate.html |title=Reliance Globalcom cable update page |access-date=30 December 2008 |archive-url=https://web.archive.org/web/20090103005834/http://www.iglobalcom.relianceglobalcom.com/iglobalcom/cableupdate.html |archive-date=3 January 2009 |dead-url=yes |df=dmy-all }} 34. ^{{cite news|title=Damage to undersea cables disrupts int'l telecom services|publisher=Xinhua|date=18 August 2009|url=http://news.xinhuanet.com/english/2009-08/18/content_11904208.htm|accessdate=5 October 2013}} 35. ^{{cite news|url=http://www.Channel4.com/news/spy-cable-revealed-how-telecoms-firm-worked-with-gchq|title=Spy cable revealed: how telecoms firm worked with GCHQ|author=Geoff white|website=Channel4.com|publisher=Channel 4 News|location=London|date=20 November 2014|accessdate=22 November 2014}} 36. ^{{cite web|url=http://electrospaces.blogspot.com/2014/11/incenser-or-how-nsa-and-gchq-are.html|title=INCENSER, or how NSA and GCHQ are tapping internet cables|publisher=Top Level Communications|location=The Netherlands|date=30 November 2014|accessdate=30 November 2014}} 37. ^{{cite news|url=https://www.TheRegister.co.uk/2014/11/21/mastering_the_internet_snowden_disclosure/|title=GCHQ and Cable and Wireless teamed as Masters of the Internet|author=Darren Pauli|website=TheRegister.co.uk|publisher=The Register|date=21 November 2014|accessdate=22 November 2014}} External links
5 : Submarine communications cables in the Indian Ocean|Submarine communications cables in the Pacific Ocean|Submarine communications cables in the Red Sea|Submarine communications cables in the Arabian Sea|Reliance Anil Dhirubhai Ambani Group |
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