SEA-ME-WE 4

From Wikipedia, the free encyclopedia

The route of the submarine cable (red); the blue segment is terrestrial
The route of the submarine cable (red); the blue segment is terrestrial

South East Asia–Middle East–Western Europe 4 (SEA-ME-WE 4) is an optical fibre submarine communications cable system that carries telecommunications between Singapore, Malaysia, Thailand, Bangladesh, India, Sri Lanka, Pakistan, United Arab Emirates, Saudi Arabia, Sudan, Egypt, Italy, Tunisia, Algeria and France.[1]

The cable is approximately 18,800 kilometres long, and provides the primary Internet backbone between South East Asia, the Indian subcontinent, the Middle East and Europe.[1][2]

Contents

[edit] Network topology

The SEA-ME-WE 4 system is divided into four segments with seventeen landing points:[3]

Segments
Landing points

1. Marseille, France

2. Annaba, Algeria

3. Bizerte, Tunisia

4. Palermo, Italy

5. Alexandria, Egypt

6. Cairo, Egypt (overland)

7. Suez, Egypt (overland/return)

8. Jeddah, Saudi Arabia

9. Fujairah, United Arab Emirates

10. Karachi, Pakistan

11. Mumbai, India

12. Colombo, Sri Lanka

13. Chennai, India

14. Cox's Bazar, Bangladesh

15. Satun, Thailand

16. Melaka/Malacca, Malaysia

17. Tuas, Singapore

[edit] History

The SEA-ME-WE 4 cable system was developed by a consortium of 16 telecommunications companies which agreed to construct the project on March 27, 2004.[2] Construction of the system was carried out by Alcatel Submarine Networks (now Alcatel-Lucent Submarine Networks, a division of Alcatel-Lucent) and Fujitsu.[2] The eighteen month construction project was completed on December 13, 2005 with a cost estimate of US$500 million.[4][2] Segment 1 construction, running 8,000 kilometres from Singapore to India, was done by Fujitsu, which also provided the submarine repeater equipment for Segment 4.[4]

[edit] Damage to SEA-ME-WE 4

For more details on this topic, see 2008 submarine cable disruption.

On January 30, 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 Telecom cables in the Mediterranean Sea. Disruptions of 70 percent in Egypt, and 60 percent in India were reported along with problems in Bahrain, Bangladesh, Kuwait, Pakistan, Qatar, Saudi Arabia and United Arab Emirates.[5][6] In India, small users felt the impact while ISPs could service large users who have more lucrative contracts.[7]

While the respective contributions of the two cable systems to this blackout is unclear, network outage graphs show anomalies at 0430 UTC and again at 0800 UTC.[8] The FALCON submarine communications cable was reported severed off the coast of Dubai in the Persian Gulf on 1 February 2008, making it the third over a two day period.[9]

Though the cause of the damage to SEA-ME-WE 4 or FLAG has not been declared by either cable operator and 12 hours of video before and after the incident show no ships being in the area,[10] a number of sources speculate these were caused by a ship's anchor near Alexandria,[5][10] while the Kuwait government attributes the breaks to "weather conditions and maritime traffic."[11] The New York Times reported that the damage occurred to the two systems separately near Alexandria and Marseilles.[12] The water near Alexandria is restricted and Egypt knew of "no passing ships" at the time.[7]

Currently, SEA-ME-WE 3 is the only remaining cable connecting Europe to the Middle East via Egypt. Data transmission capacity between India and Europe has been reduced by 75 percent, causing much of the traffic between these sites to be rerouted through the Pacific and Atlantic Oceans.[9]

[edit] Management and administration

The SEA-ME-WE 4 cable system was proposed and developed by the SEA-ME-WE 4 Consortium. The Consortium continues to maintain and operate the system. It comprises 16 telecommunications companies:[13][4]

The consortium is a hierarchical organisation which operates, manages and administers the cable system. At the top of the hierarchy is the Management Committee,[14] which steers the project.[13] Bodies subordinate to the Management Committee include the Procurement Group; Operation and Maintenance; the Financial & Administrative Subcommittee; Assignment, Routing and Restoration; and Investment and Agreement. Other bodies in the organisation are the Central Billing Party which is subordinate to the Financial & Administrative Subcommittee, and the Network Administrator which is subordinate to Assignment, Routing and Restoration.[14]

Videsh Sanchar Nigam Limited, the network administrator for the cable system and Telekom Malaysia Berhad, is responsible for the Central Billing Party.[1][15]

[edit] Applications

SEA-ME-WE 4 is used to carry "telephone, internet, multimedia and various broadband data applications".[2] The SEA-ME-WE 3 and the SEA-ME-WE 4 cable systems are intended to provide redundancy for each other.[2] The two cable systems are complementary, but separate, and 4 is not intended to replace 3.[2] Both derive from the same series of projects (SEA-ME-WE), but have different emphases. SEA-ME-WE 3 is far longer at 39 000 kilometres[16] (compare to SEA-ME-WE 4's 18 800 kilometres) and extends from Japan and Australia along the bottom of the Eurasian landmass to Ireland and Germany.[17] SEA-ME-WE 4 has a faster rate of data transmission at 1.28 terabits per second against SEA-ME-WE 3's 10 gigabits per second.[16] SEA-ME-WE 3 provides connectivity to a greater number of countries over a greater distance, but SEA-ME-WE 4 provides far higher data transmission speeds intended to accommodate for increasing demand for high-speed internet access in developing countries.[2]

[edit] Technologies

The cable uses dense wavelength-division multiplexing (DWDM),[1] allowing for increased communications capacity per fibre compared to fibres carrying non-multiplexed signals and also facilitates bidirectional communication within a single fibre. DWDM does this by multiplexing different wavelengths of laser light on a single optical fibre so that multiple optical carrier signals can be concurrently transmitted along that fibre. Two fibre pairs are used with each fibre pair able to carry 64 wavelengths at 10 gigabits per second per wavelength.[4] This enables terabit per second speeds along the SEA-WE-ME 4 cable,[2] with a total capacity of 1.28 Tbit/s.[4]

[edit] References

  1. ^ a b c d About Us. SEA-ME-WE4 Network Administration System. Videsh Sanchar Nigam Limited (2004). Archived from the original on 2007-07-06. Retrieved on 2008-01-31.
  2. ^ a b c d e f g h i About SEA-WE-ME 4. South East Asia-Middle East-Western Europe 4. Sri Lanka Telecom. Archived from the original on 2007-07-05. Retrieved on 2008-01-31.
  3. ^ Cable System Configuration. South East Asia-Middle East-Western Europe 4. Sri Lanka Telecom. Archived from the original on 2007-08-04. Retrieved on 2008-01-31.
  4. ^ a b c d e Fujitsu Completes Construction of SEA-ME-WE 4 Submarine Cable Network. Fujitsu Press Release. Fujitsu (2005-12-13). Archived from the original on 2007-03-17. Retrieved on 2008-01-31.
  5. ^ a b "Severed cables disrupt Internet", BBC News, 2008-01-31. Retrieved on 2008-01-31. 
  6. ^ The Associated Press. "Cable Break Causes Wide Internet Outage", The New York Times, 1 February 2008. Retrieved on 2008-02-01. 
  7. ^ a b Brauer, David. "High-tech mystery: Are terrorists behind recent Internet disruptions?", MinnPost.com, MinnPost, February 4, 2008. Retrieved on 2008-02-04. 
  8. ^ Zmijewski, Earl (2008-01-30). Mediterranean Cable Break. Renesys Blog. Renesys. Retrieved on 2008-01-31.
  9. ^ a b "New cable cut compounds net woes", BBC News Online, BBC, 2008-02-01. Retrieved on 2008-02-01. 
  10. ^ a b "Ships did not cause Internet cable damage", Khaleej Times Online, 2008-02-03. Retrieved on 2008-02-03. 
  11. ^ Agence France Press. "Indian outsourcing sector hit by Internet disruption", Google News, 2008-01-31. Retrieved on 2008-01-31. 
  12. ^ Timmons, Heather. "2 Communication Cables in the Mediterranean Are Cut", The New York Times, 2008-01-31. Retrieved on 2008-01-31. 
  13. ^ a b The Management Committee (MC). South East Asia-Middle East-Western Europe 4. Sri Lanka Telecom. Archived from the original on 2007-02-10. Retrieved on 2008-01-31.
  14. ^ a b Organization Structure. South East Asia-Middle East-Western Europe 4. Sri Lanka Telecom. Archived from the original on 2007-08-04. Retrieved on 2008-01-31.
  15. ^ Home page. SMW 4 Central Billing Party (CBP). Telekom Malaysia Berhad. Archived from the original on 2007-07-07. Retrieved on 2008-01-31.
  16. ^ a b Mediterranean Cable Break. REACH : Network. Reach Global Services Limited. Archived from the original on 2007-06-21. Retrieved on 2008-02-01.
  17. ^ Cable System Configuration. South East Asia-Middle East-Western Europe 3. Sri Lanka Telecom. Archived from the original on 2007-07-14. Retrieved on 2008-02-01.

[edit] External links