The Optical Networking and Communication
Conference & Exhibition

Moscone Center,
San Francisco, California, USA

Will SDM Truly Revolutionize the Submarine Communication Industry?

Wednesday, March 11, 2020
2:00 PM - 4:00 PM

Room number: 2


Pascal Pecci, ASN, France; Valey Kamalov, Google, USA; Mei Du, Tata Communications, USA


Subsea cable capacity has been growing at a dramatic rate over the past years. Until early 2018, the main effort in meeting the demand for capacity growth is to increase the capacity per fiber pair (FP). The technology has advanced in each element of submarine cable building blocks:

  • fiber design with large effective area (110, 130 and then 150)
  • high power repeater (20+ dBm)
  • more spectral efficiency (5+ b/s/Hz) transponders
  • broad transmission bandwidth (40nm, 72nm with C+L)

However, the capacity per FP faces the Shannon limit and the power for submarine network is limited by the power feeding equipment (PFE).

Recently, the new paradigm- Spatial division multiplexing (SDM) cable has been introduced, where the number of FPs within one cable has been increased (12 FPs, 16FPs…).  The main effort shifted from maximizing the capacity per FP to maximizing the capacity per cable. During this workshop, experts will discuss the impact on each element of the submarine cable linked to the new SDM cable paradigm and will give their insight on the future of submarine communication.

Topics to cover:

  1. Definition and drivers for SDM cable in subsea cable
  2. SDM cable impacts on subsea cable components
    1. Cable/fiber design: linear vs. non-linear regime
    2. Repeater design:  very high power (20+dBm per Fiber Pair) to pump farming (16-18dBm per FPs)
    3. Branching Unit: ROADM unit equipped with WSS vs. FPs switched BU
    4. SLTE:  Approaching Shannon limit vs. low cost SLTE 
  3. SDM cable impact to subsea network topology: point to point vs. mesh subsea network
  4. Open cable access: managed spectrum vs. managed FP as a granularity

Tim Stronge; Telegeography, USA
Massimiliano Salsi; Google, USA
Priyanth Mehta; Ciena, Canda
Eduardo Mateo; NEC Corporation, Japan
Olivier Courtois; ASN, France
Masaaki Hirano; Sumitomo Electric Industries Ltd., Japan
Stephen Grubb; Facebook Inc., USA

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