operation management Essay

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Subsea High Bandwidth Data Transfer Using Fiber
Optic Technologies
Richard T. Jones

Jeremy Lucas

Research and Development, Fiber Optics
Teledyne ODI / Teledyne Oil & Gas
Daytona Beach, USA rjones@teledyne.com Reliability Department
Teledyne ODI / Teledyne Oil & Gas
Daytona Beach, USA jlucas@teledyne.com Abstract— High bandwidth data transfer is critical in applications where large quantities of information are being transmitted. This is of particular interest to the Ocean Science
Community, which relies on collecting data from sensors on the ocean floor.
Multiple approaches for data transfer are illustrated, and the strengths and weaknesses of each are highlighted in this paper
Fiber Optic technology has been widely adopted in subsea communications due to the inherent reliability and the passive nature of fiber optics. A brief history of subsea fiber optic interconnects is developed, with an accent on projects in the
Oceanographic arena. An overview of the reliability of fiber optic wet-mate connectors in subsea is reported, augmented with an emphasis on case histories for subsea fields in Oil & Gas markets where the largest quantities of fiber optic connectors have been deployed.
Advancements for subsea connectivity are discussed, specifically related to a novel approach utilizing existing technology. This approach utilizes standard electrical wet-mate connectors on either end. Marinized media converters are contained within the back shells of each electrical connector which convert the
Ethernet signal from electrical to optical. The optical signal can then be transmitted over distances far exceeding standard subsea electrical Ethernet capabilities. In this way, optical Ethernet performance can be achieved with standard electrical Ethernet hardware interfaces extending the step out distance from 100 m
(limit of standard electrical Ethernet subsea jumpers) to up to 10 km. use. However, the maximum data transfer rates achievable are insufficient for technologies that demand data transfer rates in excess of 20 kb/sec. Electrical DSL offers higher bandwidth than modem technology at reasonably long distances, but the available bandwidth decreases as a function of length and still does not provide enough bandwidth for many data rich technologies (200 – 3000 kb/sec, up to 15 km). Electrical
Ethernet has proven to be reliable and high bandwidth, but is limited to short step out distances (< 100 meters). Electrical
Ethernet is extensively used for short distance subsea communications in the Oil & Gas market. In cases where step out distances are too long or bandwidth requirements are too great, optical Ethernet is utilized. Optical Ethernet is reliable with high bandwidth and is not limited to short lengths, but comes with higher cost of implementation. This cost is not limited to the optical wet-mate connectors, but also includes the optical infrastructure required in the electronics module to which the optical connectors are mated.
A graphical representation of these data transfer paradigms is shown in
Fig. 1.

Keywords–data transfer; bandwidth; fiber optics; wet-mate; connector; Ethernet



As the sensors used in the subsea environment increase in number and capability, the amount of data transmitted by these sensors continues to increase. This data must be collected and transmitted back topside where it can be reduced and utilized.
Some of the approaches to provide data transfer bandwidth explored in this paper include electrical modems, electrical
DSL, electrical Ethernet and optical Ethernet.
Conventional electrical modems can transmit data over long distances. This technology is by far the most mature for subsea

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Figure 1. Data Transfer Paradigms for subsea bandwidth

In Fig. 1, the red arrows denote that the technology can expand in the directions shown.