The Primary Nodes were installed in 2012 in collaboration with prime contractor L-3 MariPro and subcontractor TE Subcom. The Primary Nodes serve as terminal points on the backbone cable, and 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 installed in environmentally benign areas while 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, which form part of the secondary infrastructure, at the science work sites.
Primary Nodes also provide extra ports for future expansion that may span distances of >100 km.