Primary Nodes: Delivering Power and Bandwidth
(Click to enlarge) Credit: OOI Regional Scale Nodes program and the Center for Environmental Visualization, University of Washington
Primary nodes are terminal points on the backbone cable that have connection points for instruments and underwater robots. Their function is to distribute power and bandwidth (10 Gb/sec on each port) to areas where distributed networks of sensors are deployed and to high-power and high-bandwidth moorings that span the entire water column. Primary Nodes are placed in environmentally benign areas and extension cables extend to the scientific work sites.
The Primary Nodes also function as “housekeepers” for system control, out-of-band communications, and engineering monitors. They house Medium Voltage Converters that convert the 10 kVdc primary level voltage to 375 Vdc levels. This lower power is sent to Low- and Medium-Power Nodes at the science work sites. Finally, Primary Nodes provide extra ports for future expansion that may span distances of >100 km.
Junction Nodes: Serving Sensitive Sites
Direct power and communications to experimental sites (including >300°C black smokers, dense animal communities on the seafloor, methane seeps, and gas hydrate deposits) are provided by Low- and Medium-Power Junction Nodes and Junction Boxes.
The RSN infrastructure provides 375 Vdc to 12 V power to sensor arrays on the seafloor and water-column moorings, and 10 Gb/s to 1 Gb/s bandwdith. Eight instrument ports provide 12 to 48V and 10/100BASE-T, RS232 or RS485 data links. Nodes can be daisy-chained, thereby providing extensive expansion capabilities for future science and education efforts.
