Actively Controllable Switching for Tree Topology Seafloor Observation Networks

Cabled ocean observatory systems that provide abundant power and broad bandwidth communication enabling undersea science have been evolving during the last decade. To establish such permanent infrastructure in the ocean, the technology of cable network switching and fault isolation with very high reliability is essential. In this paper, we review existing switching methods as applied to a constant voltage tree topology network. We propose an actively controllable method that can configure each branch of the network only by changing the feeding current; the current level implicitly conveys the switching information. A laboratory prototype demonstrated the features of backbone switching with zero current and low voltage (less than 20 V), and active controllability of the switch.