The U.S. Navy relies upon satellite and other communications systems to make sure ships, planes, and sailors can share information across the Seven Seas. In peacetime, those systems are a given. But what happens in wartime, when satellites are shot down and other forms of comms are jammed or otherwise disrupted?
That's a very good question. The United States, NATO, and other key allies rely to a tremendous extent on satellite communications—which makes those satellites target No. 1 in a future war.
The Defense Advanced Research Projects Agency (DARPA) is developing a solution: TUNA. TUNA stands for Tactical Underwater Network Architecture, a portable, temporary communications network made up of floating communications buoys linked by fiber optic cable.
Also see related information on DARPA TUNA program and development of the WEBS.
DARPA Tactical Undersea Network Architectures (TUNA), http://www.darpa.mil/program/tactical-undersea-network-architectures
University of Washington Applied Physics Laboratory and Columbia Power Wave Energy Buoy that Self-deploys (WEBS), https://www.youtube.com/watch?v=M4nMUmxmCpY&feature=youtu.be