Regional Cable Observatory Solutions

To deliver high power and broadband communication to the ocean floor requires a number of changes to existing technology developed to bridge oceans from shore to shore. The dry-dry solution is well mastered and although it evolves over time following technological innovations, adapting it to become a dry-wet solution represents a major technical challenge. The cabled observatory system developed for the Canadian part of the north-east pacific time-series undersea networked experiment (NEPTUNE) encompasses major breakthroughs in several areas, including optical transmission, ocean engineering and powering. This paper will discuss how an industrial team led by Alcatel- Lucent along with partners L-3 Communications MariPro and Texcel Technology, in good coordination with the experts and scientists at the University of Victoria in Canada, have managed the design and development effort in all these fields. The unique optical design using a distributed WDM scheme and off-the-shelf compact metro equipment will be described. The simple yet powerful and robust IP architecture which allows accurate timing distribution based on precision timing protocol (PTP) will also be detailed. The paper will show how novel ocean engineering solutions have been used to enable the NEPTUNE science nodes to be ROV serviceable at 3500 meters water depth. Without contest, the major challenge has been the new parallel powering system, which delivers 9 KW of useable power per science node. The development of key subsystems including the medium voltage power converter, low voltage power subsystem, communications subsystem, high current optical repeaters, branching units and shore based power feeding equipment will be explained. Finally, the capabilities of the NEPTUNE Canada design to be extended to cover the needs of the full NEPTUNE Regional Cabled Observatory (RCO) or to be deployed for other applications such as undersea neutrino telescopes or tsunami detection systems will be assessed.