SINGLE AUDIO SYSTEM (SAS)

SINGLE AUDIO SYSTEM (SAS) The Single Audio System (SAS) was developed to fulfill the requirement for an integrated secure/non- secure shipboard voice communications system. It consists of telephone sets, voice-signal switching de- vices, various control devices, and field changes to existing equipment, in conjunction with other ele- ments of the overall shipboard radio communications system. The SAS is essentially the baseband (AM and/or FM ) hf, vhf, or uhf audio subset of the ship- board exterior communications system. It incorporates voice communications circuits, user control over the operating mode (both secure and nonsecure), and various degrees of operator control over voice circuit selection. Figure 2-13 shows the major equipment groups, subsystems, and their interrelationship. There are two versions of SAS: an automated system (ASAS) and a manual system (MSAS). The voice switching equipment and means provided for user control over circuit selection are the two primary differences. Information in this section applies to both ASAS and MSAS, unless otherwise specified. There is no specific list of equipment that makeup every SAS installation. There can be different types and quantities of equipment in each of the groups identified in figure 2-13. Equipment types and quantities are dictated by the communications requirements of individual ships and ship classes. The publication, Operation and Maintenance Instructions, Single Audio System, NAVELEX EE109-CA-OMI- 010/El10 SAS, identifies, in tables 1-1 and 1-2, the SAS equipment commonly used in the fleet. SYSTEM CAPABILITIES The SAS incorporates basic capabilities for setting up and operating voice communications circuits. An SAS installation provides the unique capability to communicate in a secure or nonsecure mode, at the discretion of the operator, from a single telephone or NTDS device. This single audio interface with various crypto or plain subsystems is the essence of the SAS. The SAS provides the following options: The user can select the transmit operating mode except for FLTSATCOM secure voice and PLAIN configurations. The system can notify the user of the transmit operating mode selected, both visually and with audio indications. The system can notify the user by visual indica- tion if the voice station equipment is not con- nected to a crypto or plain subsystem. The system can notify the user of any incoming secure (CIPHER) signals by both visual and audio indications except for the FLTSATCOM secure voice configuration. The user can select a voice channel and have it indicated visually. In addition to these capabilities, the ASAS version has the following features: A processor controlled, programmable voice Figure 2-13.—Single Audio System (SAS). 2-14