https://www.youtube.com/watch?v=HtP5taXF9FY
DARPAs Tactical Undersea Network Architecture (TUNA) program recently completed its initial phase, successfully developing concepts and technologies aimed at restoring connectivity for U.S. forces when traditional tactical networks are knocked offline or otherwise unavailable. The program now enters the next phase, which calls for the demonstration of a prototype of the system at sea. TUNA seeks to develop and demonstrate novel, optical-fiber-based technology options and designs to temporarily restore radio frequency (RF) tactical data networks in a contested environment via an undersea optical fiber backbone.