components   of   the   various   Federal   agencies. Essentially, all branches of the Federal Government, both civilian and military, are part of the NCS. Each department  and  branch,  however,  has  its  individual organization, methods, and procedures. DEFENSE COMMUNICATIONS SYSTEM The  Defense  Communications  System  (DCS) exists to support the three military departments (Navy, Army, Air Force) and other Department of Defense activities. The circuits that make up the DCS are government-owned  or  leased  and  are  point-to-point circuits that are long-haul and worldwide. The DCS combines many of the communication elements of the three military forces into a single communications system. Although  the  Naval  Telecommunications  System (NTS) and the DCS are two different communications systems  (fleet  and  ashore,  respectively),  they  are constantly intermixed. For example, as often happens, a naval message originated aboard ship and destined for a shore activity leaves the ship over the NTS, but final routing  is  accomplished  over  the  DCS  circuits.  The interface between the NTS and DCS is always provided by the shore communications facility. DEFENSE INFORMATION SYSTEMS AGENCY The Defense Information Systems Agency (DISA) gives operational direction to the DCS. With reference to the DCS, the DISA must ensure that the system is operated and improved so as to meet the continual long-haul, point-to-point requirements that arise. The DISA functions under the management of a director who is appointed by the Secretary of Defense. The  director  is  a  flag-rank  officer  and  is  responsible  for coordinating  the  combined  communications  elements of the three military departments. MISSION  OF  NAVAL COMMUNICATIONS The  mission  of  naval  communications  is  to  provide and   maintain   reliable,   secure,   and   rapid communications, based on war requirements, to meet the   needs   of   naval   operating   forces.   Naval communications must also satisfy the requirements of the Defense Communications System (DCS) and the National Communications System (NCS). Naval communications must always be ready to shift to the requirements of wartime. Our peacetime organization and training must be capable of making this shift rapidly and with a minimum of changes. Without this capability, our forces would be severely handicapped, and vital defense information would never reach its destination. For this reason, we have a well-defined    communications    structure,    with responsibilities assigned to each element, from the Chief of Naval Operations (CNO) down to individual fleet  units. POLICY  OF  NAVAL COMMUNICATIONS The policy of naval communications is to: l l l l l Establish  and  maintain  effective  communica- tions within the Department of the Navy; Encourage at all levels of command an effort to improve techniques, procedures, and efficiency; Cooperate with the military services, Defense Information Systems Agency (DISA), and other departments   and   agencies   of   the   U.S. Government and allied nations; Encourage development of the amateur and commercial  communications  activities  of  the United States to enhance their military value and to safeguard the interests of the nation; and Promote the safety of life at sea and in the air by maintaining communications facilities with the U.S.  Merchant  Marine,  aircraft  over  sea,  and appropriate  U.S.  and  foreign  communication stations. NAVAL   TELECOMMUNICATIONS SYSTEM The word “telecommunications” includes all types of   information   systems   in   which   electric   or electromagnetic   signals   are   used   to   transmit information between or among points. The Naval Telecommunications  System  (NTS)  is  comprised  of  all the  end  terminal  processing  equipment,  transmission, switching, cryptographic, and control devices used to transmit operational information in the Navy. 2-2