• China-US CN(China-US Cable Network or CUCN) is the first submarine cable system with direct cable routes linking the U.S. and China, reaching several countries in the Asia-Pacific region. This trans-pacific subsea optical fiber cable system was planned in 1997 and put into service in early 2000, constructed by a consortium including AT&T, China Telecom, NTT, KT, CHT etc.. China-US CNsubsea cable consists of four optical fiber pairs in its northern trans-pacific trunk between Chongming cable landing station and Bandon cable landing station, and southern trans-pacific trunk between Shantou cable landing station and San Lius Obispo cable landing station, as well as the western and eastern trunks linking Shantou- Chongming, and Bandon-San Lius Obispo respectively, with branches to Japan, Korea, Taiwan and Guam. China-US CNwas designed with 8x2.488 Gbps (STM-16) SDH over DWDM, a total of 80 Gbps trans-pacific system capacity with SDH self-healing ring protection. China-US CNwas the largest trans-pacific subsea cable system as of its commencement of service.

    China-US CN was early retired in December 2016.

  • COLUMBUS III is a 9,900 km transatlantic submarine cable linking the US, Portugal, Spain and Italy. COLUMBUS III, with 2 fiber pairs and a design capacity of 20 Gbps. was ready for service in December 1999 and decommissioned in December 2020.

    The Columbus III consortium comprises:

    • AT&T,
    • Verizon,
    • Telxius,
    • Portugal Telecom,
    • Tata Communications,
    • Telecom Italia Sparkle,
    • Telkom South Africa,
    • Telecom Argentina,
    • Instituto Costarricense de Electricidad,
    • Embratel,
    • Cyta,
    • CANTV,
    • Ukrtelecom


    The Columbus III cable lands at:

    • T1: Hollywood, FL, United States
    • T2: Ponta Delgada, Azores Island, Portugal
    • T3: Carcavelos, Lisboa, Portugal
    • T4: Conil, Spain
    • T5: Mazara del Vallo, Sicily, Italy


    Columbus III Cable Route
    Columbus III Cable Route


    The COLUMBUS-III cable system consists of five segments, S1, S2, S3, S4, and S5, with two optical fiber pairs per segment, initially designed to operate at 2.5 Gbps per wavelength per fiber pair in a trunk and branch structure configured as a collapsed ring. COLUMBUS-III was initially be configured with two wavelengths, designed to support up to eight wavelengths per fiber pair. The capacity of each fiber pair comprises thirty-two Basic System Modules (BSM), with each BSM containing 63 Minimum Investment Units (MIUs). Each fiber pair was equipped at the outset with a capacity of 1008 MIUs.

    The COLUMBUS-III cable system also has four other terminal segments: Segment A, B, C and D, as shown in the figure below: 

    Columbus III Cable System
    Columbus III Cable System Segments


    In 2009, the Columbus III consortium selected Xtera to upgrade the system capacity to 160 Gbps, with Xtera’s advanced 20 Gbps Differential Phase Shift Key (DPSK) Submarine Line Terminal Equipment (SLTE).

    The COLUMBUS-III cable system was decommissioned in December 2020, with its COLUMBUS-III Azores-Portugal portion connecting Lisbon and Azores Island remaining service.

  • Japan-US CN (Japan-US Cable Network or JUSCN) is the first high capacity trans-pacific subsea cable system using DWDM technology of 10 Gbps per wavelength. Japan-US CNconsists of four fiber pairs, each operating at 10 Gbps DWDM, with design capacity of 640 Gbit/s. Initially, Japan-US CNoperated at 80 Gbit/s with two lit fiber pairs, expanding to 400 Gbps in mid 2001 by lighting the two remaining fiber pairs each with 16 wavelengths at 10 Gbps per wavelength, further upgrading to 1.28 Tbps in early 2008.

    The Japan-US CN was decommisioned in July 2023, 22 years after its ready for service in 2001.

    In Feburary 2024, the Japan-US CN consortium selected Mertech Marine to provide a turnkey decommissioning service for the Japan–US submarine cable system, encompassing the recovery and recycling of shore-ends in both Japan and the USA and the removal of spare cable from the associated cable storage depots.

  • The TAT-14 is a 15,428 km transatlantic submarine cable system, connecting the United States to the United Kingdom, France, the Netherlands, Germany, and Denmark. The TAT-14 cable system was ready for service on March 21, 2001, and retired on December 15, 2020.

    The TAT-14 consortium comprises 11 carriers, namely, AT&T, BT, C&W, Deutsche Telekom, France Telecom, KPN, MCII, PGE, Sprint, Swisscom and Telia.

    The TAT-14 cable lands at:

    • Manasquan, NJ, USA,
    • Tuckerton, NJ, USA,
    • Widemouth, the United Kingdom,
    • St Valery-en-Caux, France,
    • Katwijk,  the Netherlands,
    • Norden, Germany, and
    • Blaabjerg, Denmark

    The TAT-14 cable system consists of four fiber pairs, each initially operating with 40 x 10 Gbps DWDM.

    Designed with a partial SDH ring protection network structure, the TAT-14 cable system has a initial system capacity of 1.87Tbs calculated as: 
    Southern route: 41 x 10Gbs channels + 640 Gbs SDH capacity 
    Northern route: 18 x 10Gbs channels + 640 Gbs SDH capacity 
    Total = 1.87 Tbs

    TAT-14 was upgraded later to have a total system capacity of 9.38Tbps.

    In September 1998, KDD Submarine Cable Systems Inc.(KDD-SCS) was awarded the Supply Contract f as the sole supplier for the TAT-14 Cable Network. The Contract Value was approximately US$1.2 billion (Approximately 170 billion yen). KDD-SCS' subcontractors for the TAT-14 cable project included Mitsubishi Electric Corp., TOSHIBA CORP., Ocean Cable Co., Ltd, etc. At that time, KDD-SCS won contracts for large-scale cable systems in the Pacific and Atlantic Oceans, including PC-1, JAPAN-US Cable Network, and TAT-14 Cable Network, with a total contract value of approximately 300 billion yen. As a result, KDD-SCS toasted to be the top of the world, superseding its antecessors, ALCATEL Submarine Networks (France) and TYCO Submarine Systems (U.S.A.), in terms of contract amount as well as technology.

    In May 2011, Mitsubishi Electric signed a contract to upgrade the TAT-14 Cable Network with 40Gbps DWDM technology. 

    On December 15, 2020, the TAT-14 consortium decommissioned the TAT-14 cable system, making its lifetime of 19 years and 9 months. The TAT-14 is the first trans-atlantic cable to be decommissioned since the Gemini cable in 2003.

    In April 2021, Subsea Environmental Services and Red Penguin Associates (advisors) were awarded the contract to decommission the TAT-14 telecommunications cable system, to remove and recycle of shore-ends in the US, UK, France, Denmark and the Netherlands as well as the deep-water segments in the North Atlantic.


    TAT-14 Cable System


  • The TPC-5 Cable Network (TPC-5 CN) is the first self-healing trans-Pacific undersea optic fiber ring network. The TPC-5 CN consists two optic fiber pairs, stretching 22560 km, linking six cable landing stations in Japan, Guam, Hawaii and the US mainland. The TPC-5 CN forms a four-fiber-ring automatic protection switching network among the six cable landing stations, each fiber pair capable of 5 Gbps transmission.

    The southern route of the TPC-5 CN was put into service in 1995, while its northern route was ready for service on December 31, 1996. The consortium member invested totally US$1.24 billion in the TPC-5 cable network.